Solar Pool Heating Challenges

Web Based Control and Monitoring

2011-11-27T12:32:00.000-08:00

As a solar thermal company, its really important to us that we be able to monitor the performance of our solar heaters. What we've learned in our 14 year struggle with this technology is that we also need to do control. We can't justify the cost of a separate monitoring device with separate power supply when it should all just be built into a standard solar controller. So that's what we did. We spent much of 2011's R and D budget on developing a web based solar controller that does monitoring of energy. As a side benefit from this work we realized that we also had a web based home automation system. We can control home thermostats with a web interface. We can also control boilers. That means that we can provide you with a spreadsheet on your computer screen (on a web page) that allows you to set schedules for your boiler. Most commercial swimming pools we run into are looking to save money on their sometimes $20,000 a year energy bills yet they are running their boilers on thermostats set at 84 degrees all the time no matter what? So why not just use a regular programmable thermostat on the boiler? Why not just do all this with existing building management systems? What's wrong with the IP thermostats that are on the market today?

The answer is plenty. We felt this whole industry needed a re-boot. Home automation, building automation and even internet based thermostats that are available today (sort of) all grew up over the last 20 years in the PC age.

COMMERCIAL BUILDING AUTOMATION:

Let's start with commercial building automation systems since Gord (my brother the IT expert) and I just finished single handedly installing two commercial solar heating systems for the City of Richmond BC. Neither system needed a solar controller because the engineer, an ex Siemens building automations guy, felt that the building automation systems were already there and control just meant a few lines of code. Now that these jobs are done we can all see that it wasn't nearly that simple and the end result is that the building management systems are not capable of storing more than 2 weeks worth of data. Also, nobody can view anything outside the local network. I don't know if these systems are working or not. The controls company provided a portal via the local network allowing certain data to be monitored in a certain way but I can't show you online and I can't control anything online. The problems stem from the fact that the local network is secure. To allow control from the internet or even monitoring in this case requires a web server on the local network. The IT people for the city are rightfully not too keen on this. These solutions are afterthoughts. The technology is all PC based so you have to store the local data on a pc. That was all fine until the internet came along with ipods and ipads and all of a sudden all this data had to be accessible on the internet. No problem. Just tunnel through the firewall and access the pc that is on the local network. Problem. That's exactly what network security is all about preventing. End result. We have no remote access, no control capability. We have $12,000 worth of building automation doing the job of a $100 solar controller.

HOME THERMOSTATS:

Look at any of the internet based home thermostats available through any of the big names. They require full access to your previously secure home network. They require a web server built into every one of your thermostats. They require an ethernet cable and power to each thermostat. OK fine if you have a new house and you've run bundles of wires to each thermostat in the home. If you've done that you already have a home automation system. If you're like me, you have 2 wires going to your thermostat. You short circuit them at the thermostat when heat is called for by the mercury bulb style room temperature adjuster and the 24VAC zone is activated. What we can do with our technology is replace the thermostat with a very simple and low cost thermostat that has a thermistor attached to it. The thermistor tells us the room temperature. A switch on the thermostat switches between manual and automatic mode. Manual means the thermostat itself controls the room temp just like before. Auto means the room temp is controlled by a spreadsheet online. Its super easy to program. You can see every temperature every hour for every day and you can change them in blocks with a simple scheduling interface and as you make changes you see the temperatures in the spreadsheet. No more trying to remember how to use the programmable thermostat interface. The main unit that is ethernet connected is plugged in in one place in the basement. It wires up in series with the wires going from the boiler control to the thermostat. I have a 6 zone system in my house. It wires to 6 thermostats and 6 zones are all controlled online. We've developed a way to do this where it is secure and does not require a web server or a computer. I don't want to baffle you with tech talk at this stage but the key to all this is the unit itself is nothing more than a client on the local network. It initiates the contact with the web server and the web server is on the internet not on the unit itself. It initiates contact no differently than when your computer initiates contact with this web site so you can read what you're reading right now. There is no security issue. Plug one ethernet cable into the main unit and you're done. We tried doing this all wirelessly through the local wireless network but this proved fussy and we ended up scaring people in terms of security (unwarranted fears abound) and we had nothing buit issues with the wireless network and the internet connection to it. We ended up becoming the person's internet support system. We scrapped all that and went ethernet port only. In a short time wireless bridges got a lot cheaper so we can still do all this wirelessly through an off the shelf bridge and none of it is our problem. Get internet to the ethernet port on our unit and it works.

BOILER CONTROLS

The same internet based thermostat programmable scheduling can be done for a boiler on a commercial (or residential for that matter) gas heater for a pool. Our unit is a solar controller and boiler controller. The most basic unit has two outputs. The inputs are 4 temperatures and a pressure and a flow rate. Among the features are the ability to set what we call a control type. An example of a control type would be when solar is on gas is off. Another control type would be that the gas heater fires to meet the desired setpoint automatically far enough in advance such that the pool temp setpoint is achieved. For example if you want the pool to be 83F at 9 am but you're letting the pool cool off overnight as much as it wants, this control type would mean that the gas heater would start firing x hours before 9 am in order to make sure the pool was 83F at 9 am. Any control type you can think of can be configured by our programmer and posted to our server so that when your controller posts data on the next 15 minute cycle it picks up the program update and you're able to use that control type instantly. This type of customization after the fact is not expensive because we don't charge for building the library of control types based on your needs. Its 5 minutes of work changing your interface. The savings possible from monitoring and controlling a gas heater that is running all year can be enough to pay for the system in one month. That's a better payback period than we could ever see from a solar heater...and it puts us in an industry where companies achieve Fortune 50 status. Get ready for the launch of this technology in January 2012. This technology is how Hot Sun will survive the current killer combination of low natural gas prices, poor economy, and the resignation that global warming is too big a problem and too long term a problem to pay much heed to when jobs and short term economies take a higher priority in the minds of voters.

Green Jobs

2011-09-07T15:37:00.000-07:00

Where are all the green jobs we were promised? What went wrong? We spent billions of tax dollars in subsidies that were supposed to jump start a green economy? From my perspective its very simple. First of all you can't realign an entire economy in the first half of the first term of a new presidency! What has happened so far is just testing the waters, making some mistakes and learning from them. As cynical as I am about political involvement in the economy, real progress has been made. Alternative energy has come to the forefront of our thinking. Solar electric technology, wind, biomass and others have been given a great demonstration and even an industry kick start. Some of the major players are now going bankrupt. What do you expect when you give a big company millions of dollars in subsidies to commercialize their technology? You not only create a business culture that depends on that subsidy and wastes it, you hurt that company's competitors who are trying to accomplish the same goals with all the real market forces to fight with. Governments picking winners and backing them seems to me like a desperate last resort effort to save a dying economy. I learned recently that one of my biggest competitors was given millions of dollars to develop a low cost solar hot water heater using unglazed solar panels. We already did just that in 1994. I'm jealous and bitter about this. I can't help thinking I missed out and I deserve some free money from the unsuspecting taxpayers but that's crazy. That flies in the face of everything we at Hot Sun have stood for from the beginning. None of this means to imply that "programs" are always a bad thing. The reality is that solar needs help. Fossil fuels are so cheap. The playing field needs to be leveled somehow. It just means we need to do better. We need to co-ordinate these programs so they all work together toward a common goal, in this case apparently, creating jobs. Or was it to get us off foreign oil? Or was it global warming we were concerned about? On one hand we closed the Chicago carbon exchange when congress quashed any idea that we might have any kind of cap and trade system for carbon. On the other hand we offer a subsidy of 30% in the form of a federal tax credit for qualifying solar technology. The qualifying technology is solar electric and solar hot water. Both those technologies have long payback periods. They aren't viable economically without the subsidies, at least not yet. The technology that doesn't qualify is our technology. Pool heating. Solar pool heating makes economic sense and we can see payback periods of as little as 2 years. Look at this monitored site in Kamloops British Columbia.

http://www.powerstripsolar.com/Control/Kamloops

So why subsidize technology that is not as viable as other technology? Is it that pool heating isn't important? You don't have to heat your pool and pools are just for rich people. Or are they? Pools are actually for middle class families with children growing up, the pools that are used anyway.

But here's the good news. All this attention to these less viable technologies has created interest in doing what we can with solar energy. People woke up and said yes, let's solar power our future. The question is starting to become how? We're almost at the point in history where the public and the government purchasing agents have recognized that solar is great but its too expensive. Now that the economics questions are being asked we're slowly getting the attention of various potential clients who are just starting to understand that small scale solar hot water heating is kind of hopeless. You only spend $300 a year heating hot water for your house and a solar hot water heater is $8,000. We can do one with unglazed panels that won't produce as much as the glass covered beast that saves about $150/year. We can only save maybe $100 a year but we can do it for $2500. Even so there's no real market and no-one doing this wants to take a compromise on performance. When a buyer gets educated and still wants to do it she's not doing it for the short term payback anyway. She's investing in cool technology to improve her home and she is thinking long term. Large scale hot water heating is where the economics play a role. We'll soon finish an installation in Richmond BC on an Aquatic Center. We're preheating 16 showers with a 5000 gallon tank and 2000 sq ft of Powerstrip When you're heating hot water you're really heating cold water up to hot water and if the load is large you can put up a lot of solar and collect a lot of energy just heating water from 10 to 30C. That's all the roof space that is available so why put expensive solar panels on it that operate more efficiently at 60C when the highest the collectors will ever get is 30C? This project would never have gone ahead if the City of Richmond hadn't first decided they wanted solar heating. They took their time and didn't get caught up in the now expired grants in Canada. They hired an engineering firm to play judge and jury and ultimately designer and general contractor. We're just getting started with some smarter approaches. Ironically it only happened because the industry did get a boost from the subsidies and those benefits will take a long time to play their way thru the system. Its worth mentioning since it is so ironic and comical that we never took advantage of any of the subsidies to get to this stage as a technology developing company. The ones who did are mostly starving and close to bankruptcy now that the grants are gone. The exact same thing will happen in the US if and when the tax credit disappears. We need to learn from the tax credits. One thing the US could learn from Canada is that you have to cancel the tax credits to learn what their spin off benefits really are. With the grants in Canada we were stuck. Nobody was looking at anything but how to take their share of the free money. Our technology was overlooked.

In BC there is a carbon tax that increases over time. Its not going away. Very smart politically. It is why 30% of our sales are in BC this year. Last year our sales in BC were 3%. The subsidies in the US will not do anything if there isn't something long term like a carbon tax to motivate the market in the right direction. Nobody likes a new tax but if done right it can mean lower taxes elsewhere so its just a tax shift not a new tax. Without cap and trade or a carbon tax or carbon regulation there is no point in subsidizing solar energy in the US. Burning things to create energy will always be cheaper than trying to collect solar energy or even wind. We have to make the conscious decision as a society that we are going to reduce our dependence on fossil fuel. We were on the right track for a while but we got sidetracked with the bad economy. We need to keep our eye on the target and keep moving in the right direction. We've only just begun. People aren't even thinking carbon tax in the US yet. That attitude has to change before anything can begin because without a carbon tax we'll just burn oil and gas and when that is gone or if it gets more expensive we'll burn the forests and when they are all gone we can still burn each other's dead bodies. Without some kind of regulation you can't blame us for just burning the planet to keep ourselves warm. Its complicated and it'll take time so please don't give up on the alternative energy/ green movement before we've begun.

Cheap Solar

2011-07-19T14:02:00.000-07:00

Cost is an issue with solar energy. It always has been. Its not really that solar is so expensive, even PV and fancy hot water systems. The issue is really that energy is so inexpensive. To compete with natural gas at $1/therm we really have to pay attention to what we do to collect solar energy. This is why Hot Sun Industries has always believed in unglazed technology. You don't need all that insulation and glazing to deliver a large percentage of the solar gain to the load as long as the load is low temperature as in a swimming pool or in the first 2/3 of the ramp up from cold city water to hot water. Now within the category of unglazed solar collectors we have some significant variation. The market demands the lowest price and many have attempted to bring the cost of solar down and they have done so successfully simply by cutting out a lot of the middle men. Middle men like Hot Sun. To get cost down you cut out the resellers who implement the systems by marrying the mechanical systems of solar and pool together so that the investment actually works. There are also roofing issues and plumbing issues. Of course what happens is we at Hot Sun get calls every day from people who have purchased the lowest cost items available and then they have questions for our experts. We want to help but its totally unfair of us to provide the expertise while our bottom line minded competitors walk away with not just the profits but with the freedom from any liability associated with the advise their untrained support personnel might have not provided. Sorry for the venom in that last sentence. Our answer to this is to provide expertise on forums and blogs so today I've invited Eric O'Brien to tell everyone about his experience buying some 2x20 SunHeater solar panels and let's see if we can make the cheap stuff work at least for a little while until he's proven to himself that solar is a fabulous technology in terms of power capability. Once he and others reading this blog finish their experiments with the cheapest solar they can find they will naturally value the investment and realize it is worth spending a little more in the replacement phase in order to get something that is less problematic and can be fitted to the roof without making a mess of the home and the integrity of the roof membrane. So fire away Eric and anyone else who wants to get in on the discussion. Let's expose the internet solar industry for what it is. Lowballers selling the cheapest thing they can with minimal support. With no expertise you have no warranty recourse because nobody knows what is wrong. Eric's case is typical and it demonstrates the importance of understanding pressure issues. Nobody understands pressure so you really need to buy solar from someone who does because without that understanding things just plain fail and nobody knows why and it isn't the fault of the solar manufacturer.

Canadian Government Funds Solar Energy Solutions Using Wrong Technology

2010-12-09T09:16:00.000-08:00

In the rush to jump start the green economy and promote the use of renewable energy, Municipalities all over Canada are rushing to put the lag bolts through the rooftops of the buildings over their public pools. Solar thermal is the buzzword of the day in these circles and the gold rush is on. These pools are used year round and this is Canada. Regular swimming pool solar panels made of plastic with no glass over them are fine in the US but in Canada the thinking is that we need insulated boxed and glazed collectors and high tech selective surfaces. That is the sum total of the entire analysis that went into some of the current federal funding initiatives and resultant mad rush on the part of municipalities to take advantage of it without time to consider the options.

Saskatoon's Lawson and Harry Bailey Pools have already completed their investments in "solar thermal". A computer simulation study was done using the software developed by NRCan (the same organization responsible for some of the funding for these projects) and verified with high level monitoring on three sites using unglazed swimming pool heating solar panels. This study indicates that there is not a significant extra solar gain possible with the more expensive collector types just a much higher cost and much longer payback periods As it turns out there isn't as much sun available in winter and what can be collected can not be collected efficiently even with the more expensive technology. In the season when the most sun is available, it turns out that low cost unglazed swimming pool heating solar panels are more efficient per area not just per dollar. The return on investment is at least 3 times faster with this more appropriate technology and that return on investment is predicted to be less than 10 years. That's without any rebate from the taxpayer. The unglazed plastic collectors carry a 15 year warranty and entire contract installations can be guaranteed fully for 10 years.

Solar systems can be installed as ESCO's, energy service contracts where the savings from the system pays the capital cost over time. This free market job creating activity is sabotaged by the government rebate program and what can inadvertently happen is that we end up coming to the wrong conclusion. We conclude in the end that solar pool heating isn't viable when in fact it is. On the other hand the government rebate program fosters awareness of all things solar and this can motivate decision makers into investigating what solar opportunities may exist.

Dryden Ontario's municipal pool just completed their newest solar mistake, a repeat of history. They just replaced an existing boxed and glazed collector system without any analysis of the economics whatsoever. Its not even that technology has improved, its that the technology was there the whole time and nobody looked at any of the history. Richmond BC had plans to make the same mistake on all of their pools this year. Hopefully we convinced them otherwise with another simulation study in time. The list goes on and on.

These simulation studies are available at http://www.h2otsun.com/PG3.html and details on the actual software used and our own verifications of it and the history are available at http://www.h2otsun.com/enerpool.html

Ken Wright, Pres
Hot Sun Industries Ltd.,
Burnaby BC
Hot Sun Industries Inc
Poway CA
604 298 7095

The Carbon Conundrum

2010-11-25T11:58:00.000-08:00

Miscalculation of carbon content in fuel throws off footprint calculations.

Everyone agrees that we have to reduce the amount of carbon we are putting into the atmosphere. Even if you don't believe global warming is an immediate threat, you agree its just a matter of time. No realistic person believes that human beings can continue to consume the earth's energy resources and pump the resulting carbon into the atmosphere indefinitely. No-one has ever questioned Al Gore's carbon concentration in the atmosphere charts showing an exponential increase since the beginning of the industrial revolution. We all agree on this so why can't we seem to get it together enough to start doing something about it? Those most concerned want a carbon tax because obviously we need to put a price on carbon if we are to move collectively toward a reduced carbon emissions future. Problematically there is usually too high a political cost to enacting carbon tax legislation although it was implemented successfully by Gordon Campbell's Liberal government in British Columbia. He's now had to resign over his implementation of an additional tax that came as a result of harmonizing the federal goods and service tax with the provincial sales tax. British Columbians seemed more concerned about how a tax was implemented than the merits of the change in taxation itself!

Cap and trade it touted as a way to price carbon with less political cost but even cap and trade has little hope of becoming legislation any time soon in North America. The Chicago Carbon Exchange will soon be closed down because with republican control of the senate there is no hope for cap and trade legislation in the US. Similarly in Canada the conservative controlled senate has vetoed against the Climate Accountability Act of 2006, an act that demanded government reduce carbon emissions to 1990 levels by 2020. Maybe the right wing isn't so short-sighted. Maybe the conservatives are actually being practical in this case. How on earth can any good liberal think that a cap and trade system could actually be administered fairly without corruption. Looking at the Chicago Carbon Exchange web site we see that there are horrendous multiple levels of impossible legalistic approvals required for anyone to try to sell carbon credits. In that massive bureaucracy there is no establishment of any kind of standard for quantifying how much carbon there is in a gallon of fuel.

Interestingly when we look at carbon footprint calculations everywhere from the iphone app to the carbon equivalent calculation done on a monitored solar energy system we see irreconcilable differences. People do not understand carbon. What is it? Its in the form of carbon dioxide, a harmless weightless gas. How can I possibly be responsible for putting 4 tons of it in the air just from the use of my one vehicle? It doesn't seem right. Its all very mysterious. The scientists are up to something. Citizens the world over are concerned about carbon but their only quantification, their only count is their energy costs. Energy costs are so artificially low that for typical wealthy North Americans these provide almost no motivation to reduce carbon output whatsoever. Furthermore the dollars we pay for energy in different ways do not represent the distribution of carbon. In other words, how much carbon is in the $200 natural gas bill for heating my house in December or heating my pool in April vs how much carbon is in the $200 plane ticket I just bought to fly to Mexico for a vacation. How much carbon is in the gallon of gasoline vs the same $3.00 worth of electricity. What about the transportation of the natural gas to the home or the carbon used refining the propane? Some carbon calculators give the weight of carbon dioxide instead of carbon. Carbon dioxide has two oxygen molecules weighing 16 each compared to that one molecule of carbon weighing 12. Do we care about the oxygen? Is that part of the carbon footprint we should be worried about? I don't think so but I'm not exactly sure and I have a degree in mechanical engineering and 24 years full time doing energy calculations in order to try to sell you a solar swimming pool heater. The point is that we are nowhere near even being able to quantify the carbon that we are all so concerned about. We have to know how much before we can even begin to talk about putting a price on it and maybe we don't even need a price on it. Maybe people will strive to reduce their footprint if they can just figure out what it is.

At Hot Sun we've stumbled upon part of the solution accidentally. We've been developing our own web based solar monitoring and boiler control technology. You can see this in action in real time at http://www.h2otsun.com/Gordon/coronado Historically solar pool heating has not been done successfully with commercial pools because of setpoint conflicts with boiler controls. We've always needed better boiler controls especially when a solar heater complicates the situation. We've barged ahead in the last few years installing megawatts of solar pool heaters at large commercial facilities like the Coronado High School and they don't work. Monitoring was the key to learning why. Look at the Coronado calendar and notice that the solar was never "firing" Nov 20 through Nov 25, 2010. It should have been but the boiler setpoint hysteresis was a little high and at one point someone turned the boiler up to 92F and forgot to turn it back down. $100 was wasted. Nobody knew. The need for this higher level of sophisticated control of boiler and solar that our new web based monitoring will allow will solve this problem but it opened the doors for solving other bigger and more general problems. Of course we will publish on the web site for the home or business or facility in question the equivalent carbon as well as dollars saved. Its the carbon that became interesting because if we're keeping track of the carbon reduction then it becomes really easy and interesting to keep track of all the carbon used in (for example) the household over time. Plug in odometer readings and dates, data from utility bills once a year, airmiles flown, and suddenly you are aware of your carbon footprint and carbon becomes something measurable and measured. Now it means something to walk the kids to school to school or pay attention to an inefficient boiler. People who want to do something about carbon at a personal level suddenly can see the effect of small changes in terms of carbon instead of dollars. At the end of "An Inconvenient Truth" Al Gore suggested we all change our lightbulbs to compact flourescent and we all did and our electricity bill didn't change. Who can blame us all for losing interest and even turning sceptical on the whole global warming alarmist movement. Hey Al, What about that oversized mansion you call home? For all we know he may use less carbon in his household than someone in a much smaller house. He could defend himself by showing us his carbon footprint. We are all demanding that government do something when we are clearly being wasteful personally and unwilling to accept additional Pigovian taxes to force us to burn less. Stay tuned for online carbon footprint quantifiers. Step one is not to price carbon. Step one is to measure it!

Ken Wright is President of
Hot Sun Industries Inc of
Poway California www.h2otsun.com

Hot Sun implements solar swimming pool heating solutions, the only solar energy solution where we want you to know the numbers!

Solar Heating is Flexible

2010-04-27T13:44:00.000-07:00

Up until just a few years ago, solar swimming pool heating was far and away the largest use of "solar energy". The reason is simple and straightforward. It makes economic sense. It competes head on against very inexpensive natural gas for heating swimming pools. The unglazed (no glass over the collector) plastic collector is low cost per area exposed to the sun and when heating low temperature water like a swimming pool (or even pre-heating domestic hot water) the efficiency is high. In other words a large portion of the solar energy exposed to the collector is collected and delivered as energy to the load. This simple and obvious combination makes for the most cost effective and therefore most viable solar energy solution. Over the last 37 years this solar energy market has thrived but there have been ups and downs.

The first low cost unglazed solar collectors for swimming pool heating were introduced around 1969 under the trade name "Solaroll". The product was made of a synthetic rubber called EPDM. It was a flexible collector. It thrived. In 1972 Freeman Ford, the founder of "Fafco" introduced the first rigid collector. This collector, still in production today, was made of a type of polypropylene. The header pipes are permanently attached to the absorber sections in the factory resulting in fixed size collectors. 4x12 has become the most common size. The advantages to this design are that they are low cost to manufacture and low cost to install. Solaroll by comparison, required the installer, dealer, or homeowner to attach all the headers to the flexible fin-tubing after cutting the fin-tubing to length. This extra work traded off with the extra capability in terms of being able to fit the collector to the space. In addition these original flexible collectors could be used in areas where freezing was an issue. If water is trapped inside a rigid collector and it freezes the tubes break and the remedies require sealing off entire flow cores in a way that is unsatisfactory to many consumers. The flexible Solaroll on the other hand could be mounted flat on a roof where water will not drain out. It could freeze solid with water in it. This was the state of the art in the industry 30 years ago? What happened since? Solaroll no longer exists and Fafco was copied over and over again and today 75% of all solar pool heating is done with rigid polypropylene boards sold under brand names like Aquatherm, Solar Industries Aquasol, Techno-Solis, Vortex, Heliocol , and others. Most in the industry can tell you through their own bias that the flexible synthetic rubber collectors like Solaroll had a fatal flaw. Chlorine in the swimming pools caused the flexible material to break down and turn the pool black. This phenomenon is sometimes known as black pool disease. One of the big chemical companies proposed a solution. It was a polypropylene based flexible extrusion called Santoprene. As the story goes, it broke down faster than EPDM and the result was massive business failures in the industry. From this point forward the rigid polypropylene collector industry thrived.

But the rigid 4x12 panels were limiting. They couldn't be applied to flat roofs without fear of freeze damage and they had to be bolted down on flat roofs which is risky in terms of roof leaks. Available space could not be fully utilized and what could be less esthetically appealing than big black rectangles strapped down on a rooftop. Where there is demand there is supply. The epdm rubber tubing collectors came back, slowly and gradually. Its been 30 years since the major fallout, long enough that the whole history can be denied and denial truly is the name of the game. Even yours truly, a so called solar expert was taken. Enersol Solar products has been selling the same extrusion for over 27 years. Hot Sun installed a 2000 sq ft system in North Carolina using Enersol EPDM and it took only 3 years in the field for the system to start churning black crud into the pool.

Enersol did lab testing and concluded the epdm was not the same epdm their solar panels were made of. There must be something else breaking down somewhere in that 100 feet if 1.5" pvc pipe and 31,752 feet of 1/8" ID epdm tubing covering over 2000 sq ft!! Hot Sun was the first company selling EPDM (since 1990)to actually admit that they knew what was happening when the report of black crud in the pool came in. Luckily Hot Sun had decided this was risky long ago and had developed a plastic based alternative. The experience in North Carolina was the final straw. Hot Sun now sells nothing but plastic based flexible extrusion. We have a warehouse full of quarantined epdm if anyone is interested.

There is an undeniable appeal to using EPDM. Its cheap and its tough. It usually lasts long enough that these issues occur well into the lifespan when most people don't even remember who they bought their systems from. People generally aren't willing to sue over a few thousand dollars worth of material that has saved them thousands of dollars in pool heating cost. The important thing for most people is to get the system operating again asap!. As a result we see more and more epdm solar products on the market each year. Its an inconvenient truth but aren't we all guilty of ignoring these in our everyday lives? Its human nature and that is going to be the topic of upcoming blogs. Human nature and how it relates to energy politics. Global warming denial. First some final words on flexible collectors. Hot Sun's solution is not without its downsides too. There is no perfect answer. We have to use a mechanical or an adhesive connection to join the tubing and the headers. It takes more time to assemble. Theoretically flexible plastic is not as strong as flexible epdm so we have to be more careful with system pressure but what we've found are better and better thermoplastics such that today our flexible plastic is as strong as most competing epdm products with one major distinction. Powerstrip is guaranteed not to break down for 25 years. EPDM products can't have water left in them over winter due to "freezing issues". That mindbender really means that if you leave water in the epdm tubing and it heats up the black crud will come off the solar panel and go into the pool. Freezing seems to trigger the release, we think just due to the physical stretching. We don't believe anyone else has even tried to resolve the issues with epdm in the solar business. The seal manufacturers have certainly acknowledged this problem. Here we're talking about chlorine in drinking water (much lower concentrations) and city water temperatures. The effect is known to double with every 10 degree increase in temperature. The solutions are special compounds that are very expensive and even then the effect is just reduced. No-one in any major company that employed lawyers and sold large scale industrial processes would dare apply epdm to heated water that was sanitized with chlorine especially when the chlorine by-products, the real culprits, the chloramines, remain in the water indefinitely as they do in a swimming pool. It doesn't happen every time and many times it takes 15 years. Each manufacturer has some 20 year old examples of cases where it didn't happen and those cases are pointed to as proof that it must be something wrong with your chemistry. Its so unbelievable that this kind of thing goes on that it is hard to make the case against those that are guilty but it is human nature to deny threats to one's livelihood. In this mature industry the approach is sales based. Its business. Its not a problem until another major legal fallout makes it a problem.

Meanwhile Hot Sun continues its technology based approach and the technical gap widens. Our approach is more difficult but stick with us. It'll be worth it in the end. Rome wasn't built in a day. Today Kevin in my blog about in floor cleaning decided he couldn't take the pool builder's resistance any longer and he told me he was backing out of the solar job. Stick with it and pay the price Kevin. Somebody has to defeat the ignorance otherwise the status quo wins out. Once you do win out, the rewards will come. The dumb pool builders will be replaced with smart ones as the information age continues and you will be the expert they all come to. Its all about expertise.

Cooling Your Pool With Solar

2010-04-16T12:10:00.000-07:00

In many climates pools gets too warm just from the direct sun heating them. A common joke we used to hear in the early decades of solar pool heating was that my pool is already solar heated. Its warm all summer just from the direct sun. Its true. The top surface area of the pool sees the same solar energy per square foot as the solar collectors up on the roof. The pool is also losing some of this energy at the same time same as the collectors. If the pool is in the shade it still has the same losses but 100% of pool top surface area in collector area is missing from the energy balance equation. That is why shading on the pool is almost a one to one relationship in terms of how we have to size solar. For every square foot of shading on the pool we need almost one sq ft of solar collector to get that pool back to the same temperature it would be at if it was in the sun. A shaded pool is a cold pool so we get a lot of demand for solar from these homeowners. When we factor in the shading AND size the system to extend the season as we normally would we're sometimes telling people to expect the pool to be 30 degrees F warmer than they are used to. Pools that are in the sun have the opposite problem. They get too hot on their own even with the cover off. Today I had an e-mail from someone in Slidell Louisiana asking about cooling a pool with solar and I thought I'd share my response.

Yes solar is very effective as a pool cooler. Many companies used to include the automatic cooling feature in their automatic controls but over time eliminated that feature because solar turning on automatically in the middle of the night woke everyone up. Air flushing through the pipes makes noise. We had one customer who left the system in cooling mode for 2 years without knowing it. For these reasons we don't automatically keep the pool temperature down. We just turn solar on manually at night on purpose.

Its hard to quantify it because its radiation heat loss as well as convection but it definitely does work as a pool cooler. Its very important in heating pools that we don't run solar when the sun isn't out because it will cool the pool. The more common use is as a house cooler. In this case the solar gain is taken off the house reducing or eliminating air conditioning loads. Now the pool gets too hot so you run solar at night to cool the pool. In other words you run solar all the time manually not automatcally (you just switch the auto controller to test mode). Heating beats cooling because the sun is hotter than the night sky so you are still looking for ways to cool the pool but what isn't in question is the value of being able to pump water thru the black thing on the roof.

My best guess is that on a day you might gain 10 degrees from solar you might lose 3 degrees from running solar at night. Once we have these systems monitored we'll be able to look at this kind of thing quantitatively in the real world instead of trying to employ the Stefan-Boltzmann equation based on an equivalent night sky temperature that depends on cloud cover to calculate radiation heat loss and then add that to estimated convective losses. Real life is so much more real. Nobody has proven global warming mathematically. We need to see glaciers melting and extreme hurricanes before anyone pays attention. I use global warming as an example of how complex the heat balance on a swimming pool can be. The variables are too variable for anyone to be able to say with certainty what is happening but we have done a lot of work toward the goal of predicting what will happen to a pool after we solar heat it and a big part of that work is verification. Our charts under sizing have been verified hundreds of times on real situations. Whenever anyone asks us to quantify our claims we point right to the charts for an area close to them and we extrapolate up or down based on the variables. We try hard to not make unsubstantiated claims. You lose credibility really quick when you start playing salesman and telling people what you think they want to hear. Its a very tough habit for any professional salesman to break so if you're a salesman break the habit. Get technical. We have to be diligent about our technical approach to this industry.

Getting Feedback from Solar Pool Heaters

2010-04-15T16:43:00.000-07:00

It used to be that there were 3 companies making differential thermostats that controlled solar pool heaters. On residential jobs we're almost always controlling a 24vac 3 way valve. Three way means three ports. Really they should be called 2 way because the flow comes in one leg and can only go out two other ways. Solar on or solar off. Compool, Goldline, and Heliotrope controlled the market for these low tech analog controllers. We liked Heliotrope because it was a small company like us and it was technically based. Whenever we had an issue they were all over it not just satisfying the customer but also addressing the technical issue so they could build the solution into their product for next time. They were small enough to be able to do that. You can see pictures and more on automation at www.h2otsun.com/auto.html One of the things we didn't like about any of these controllers was the relays. Solar controllers with the relay feature can bypass the timer for the pool pump and turn the pool pump on when solar needs it on. This way you can leave your 2HP pump running the 3 hours a day you're used to in your futile attempt to save electricity cost and minimize noise. Both of those problems were caused by the fact the pump was over-sized in the first place by the way. The relays in these analog controllers were mechanical not solid state. These became the single largest headache we had in those days. Goldline led the pack toward going digital first with a solid state relay. Great but their relay only switched one leg of the 220VAC pump power. I don't think that is up to any electrical code anywhere. I've seen sparks a few times thinking both power legs were off when I went to rewire a pump. I always short things out with a screwdriver to make sure there is no power. I'm a power coward. I stayed alive that way. Don't be a hero. If you can't get access to the breaker and you're relying on the switch or the relay, put signs up (and locks) so nobody touches anything while you work. Short everything out with a screwdriver with a well insulated handle first and even then, don't touch the bare wires. Why die if you don't have to. You're only making $200 an hour here. Its not worth it.

Heliotrope had a big fire and burned to the ground about 8 years ago. The owner, Sam Dawson, first retired on the insurance money. Then he brought the business back to life and sold it to his son-in-law. In between those times we decided it was time for a digital solar controller. Maurice Duteau is the owner of Temco Controls in Shanghai. He and I graduated from Mechanical Engineering at UBC in 1984 together. That's him with the 4 pound rainbow I guided him to last summer. Temco now looks after our header pipe production as well as our roof sensors and strap brackets and strap clamps. He had a staff of low paid engineers he put on the controller project. We developed a wonderful solar controller with every feature I could imagine. The menu tree allowed you to lock out spa mode when solar was on and you were in pool mode. (The pipe to the spa was used as our low pressure return in many cases meaning you can't use spa mode without solar off first). We could adjust the differential wherever we wanted. We could control the pool pump on a programmable schedule. We could lock out the gas heater on a weekly schedule. That was just the beginning. What I really wanted in a solar controller was monitoring. I want to know how much energy was being produced. I wanted to be able to take real data off a real system and prove that solar pool heating in that situation paid for itself in x months. Its just a matter of logging a temperature difference and a flow rate. Maurice and I worked on this thing for years. We got sidetracked over and over but we kept at it. It was starting to get messy because we needed this unit to be UL or ETL approved and this proved to be expensive. Even low cost ETL meant hundreds of dollars a month in fees so they could make sure our manufacturing stayed in compliance. Understandable but too expensive and risky for a small group like us. Then suddenly we learned that Pentair had come out with the Suntouch. It was a digital controller and it had nice optional 3HP solid state relays that could switch both legs of power. It had all the digital control capabilities we'd built into ours and it could control pool spa valves, tie into an Intellichlor salt water system and most of all it could control the VS3050 pump. Pentair was too big and this was too good and too cheap for us to compete so we gave up immediately and have been sucking up to Pentair ever since.

The Suntouch is great and Pentair has been great with service and support but the Suntouch is built by a pool company. It has no failsafe features for solar and it can't really do much to optimize the gas heater function when used with solar on commercial pools and of course the idea of monitoring and keeping track of energy delivered was far off Pentair's radar.

A few years went by

Our dealer in new Zealand, Dave Collier at DSC Solar is a controls guy and he's been working on a wireless solar controller that will log the data we want. Its the coolest technology in the world because it allows us to watch what is happening from anywhere online. He's been slogging away at this for years but like Hot Sun and Pentair, the big guys beat us to the punch. Wireless is all the rage right now and finally a development kit came on the market about 2 months ago. My brother the electronics whiz bought one and almost caught up to Dave overnight. We now have the capability for about $100 in materials (plus $300 for an optional flow meter) to log the energy produced and collect the data wirelessly through a local wireless internet connection assuming one is present. If no wireless internet connection is present we can walk by with a laptop and download the data. Storage is huge so we can do that annually. We're planning several sites to incorporate this technology and in each case we want that wireless connection so we can show the world. This technology will send an e-mail or trigger whatever function we want if a set point is reached. For example if collector pressure exceeds a setpoint an e-mail sends out automatically alerting to the problem. We can watch online the energy being used by the gas heater if we want. We can adjust the program that controls the gas heater remotely if we find it is using more fuel than we want to allow. We can alert the customer long before the sting of several months of early season gas heater use shows up in the form of a gas bill. If the flow drops because the filter needs to be cleaned an automatic e-mail can be sent. By monitoring the energy we will be able to demonstrate the true economics and the true capability of this technology. We're very excited to be presenting this technology very soon. Its long overdue. We get around the UL requirements because it only uses 24vac and it can be built right into the Suntouch controller. With the pressure sensor we have now solved the riddle of how to deal with all the variable speed drive pumps and the concern that a seal will fail and collectors will be exposed to high pressure. What could be better than shutting the solar or the pump off and e-mailing the serviceman or the customer or both. Watch for this option on our web site www.h2otsun.com

In-Floor Cleaning

2010-04-10T10:39:00.000-07:00

In-floor cleaning system on pools are common in Arizona. Not too common elsewhere. A distributor head that looks like an octopus distributes flow from one set of nozzles on the pool floor to another moving dirt along and toward the drain where it is sucked up by the pool pump into the filter for removal later. The dirt gets kicked up of course and technology has changed so sometimes the idea is the nozzles just kick the dirt up everywhere and skimmers and bottom drains take the dirty water to the filter. Its a wonderful concept but it requires a lot more pump power than otherwise. Normally we'll see 2HP pumps on these pools. A pool without in-floor cleaning would only need 1/2 or 3/4HP. The power requirement is threefold higher before we even consider the load. The infloor cleaning system requires more pressure. That means the pump works harder. That means it uses more energy so a pool with a 2HP pump and infloor cleaning running the same 8 hours a day might consume 5-10 times the energy as a pool without the feature. That means 5-10 times the electricity bill.

We are working with a dealer in Tucson at this moment, Kevin, we'll call him. Kevin's PV (photovoltaic solar electric systems for electricity) company just installed a $90,000 solar electric system for a customer and the new pool is getting solar heated as well. The customer is more comfortable with Kevin than the pool company's recommended solar company who wants to put large coils of polyethylene pipe on the roof. Kevin has demonstrated our flat roof no roof penetration ballasted Powerstrip system (not published on www.h2otsun.com yet) to the customer and he's impressed. The problem is the pool company wants to install a 2HP pool pump with infloor cleaning. We've recommended a variable speed pump to minimize operating cost and to allow fine tune adjustment of the pump after the fact so minimal energy is wasted with the infloor cleaning feature. They finally gave in and agreed to this but not without a lot of resistance based on the premise that in-floor cleaning systems need to operate all the time the pump is on. If that is true then there is little electricity savings to be had. What we believe to be the case is that infloor cleaning does not have to be on all the time. Customers we have talked to have reported that 2 hours a day is plenty. With a variable speed pump we can program infloor cleaning to come on for 2 hours near the end or start of the filtration cycle. During these times the load is high but we can minimize it by setting the pump speed just right. With a Pentair VS 3050 (our preferred vfd pump) for example, we have the choice of 3050 different operating speeds. Not only do we get to set the speed just right but at any one operating point the motor on this variable speed pump will be 92% efficient whereas a regular motor on a regular pump is more like 55%. That's the motor. The pump that is attached to the motor also has an efficiency that must be multiplied by the pump efficiency to get the overall efficiency (we call the whole thing the pump normally). The pump part of the pump will be more efficient on a single speed pump because the impeller and housing are designed for that one speed instead of 3050 speeds but the difference isn't as much as the motor. Overall we typically see efficiency 30% better with a VS3050 pump (pump/motor combo) than we do a single speed pump doing exactly the same thing. I have this data straight from the horse's mouth. My friends at Pentair gave me access to actual test data that was done leading to the Title 20 law in CA (Jan 2008) that stated that anything over 3/4HP was illegal on a residential pool (retrofits and new construction). There's talk that variable speed pumps may become mandatory next round. Its socialism I tell you and its the best kind. The pool industry proved that it is incapable of taking efficiency into consideration in their pool designs so Arnold had to step in and terminate their oversizing habits. Now its not just me and a few top pool design teachers spouting off about 1/2HP vs 2HP. Now the pool builders themselves are all about energy efficiency in CA. Not so much in AZ.

Ironically its easier to tie solar into a pool with an oversized pump than it is after we've successfully solved the pressure problem by changing out the customer's pool pump for something sized more reasonably (or gone variable speed). If the pool is simply a pool with infloor cleaning its definitely a pressure situation so we employ a pressure design. Something like case 7 at http://www.h2otsun.com/pk is appropriate. Note that with a high pressure design what we are doing is regulating the pressure. Its easy. We just limit the flow we allow to go to solar. We don't divert flow to solar. The pressure wants to send the water up to solar. The pressure is higher than the roof height. What we are doing is limiting the amount of flow we allow to go to solar and dropping the pressure to the solar collectors. It sounds so easy but its just the beginning because we need to get this low pressure water from the solar panels back to the pool still. We need another pipe that isn't under pressure. Water won't flow from the low pressure solar panels to the high pressure pool plumbing unless we pump it and that would be crazy. We're not adding another pump to force the water from solar back into the pressured plumbing. The best analogy I have ever come up with for this is the kitchen sink. If you open the tap on the kitchen sink you are just opening a valve teed off the pressure line. You aren't diverting anything. The pressure drives the flow from high pressure to low pressure. Once the water leaves the tap its at zero pressure (zero gage pressure equals atmospheric pressure which is 14 psi- zero is atmospheric on any gage). Water flows because it has a place to flow to that is not under pressure. The drain pipe from the sink to the sewer is open so its under no pressure so water flows there. If we tried to force the water back into the pressured pipe it came from it wouldn't flow and the whole kitchen tap line would go under that full system pressure. Note that with no flow the whole thing is under full pressure. You can't regulate pressure without having a low pressure place to return the low pressure water to the pool through. Its a great analogy and occasionally a pool builder stops arguing all-knowingly when this analogy is made and many times we've opened the door of doubt just enough that we start to see an opportunity to win another one over to our side. Our side, by the way, is the side that says we all have a lot to learn from each other and if we are protective and defensive we aren't open to learning anything from anyone. That's old school. New school is the public is smart and has access to this kind of information so you better get with the program if you don't want to get embarrassed by someone like Kevin who admits right up front he has no pool mechanical experience yet there he is making a pool builder with 30 years experience look foolish and costing the pool builder and his gravy train of kickbacks for recommending a truly bad solar company and product, one customer at least. Its unfortunate that the solar guys have to argue with the pool guys in the first place. We are the mechanical design experts and we are the ones who have to take responsibility for a very long time for this large array of thin black plastic expanding and contracting on the roof top freezing in winter to boiling in summer not to mention the rest of the pool mechanical system. Pool builders don't take responsibility if the filter explodes. The solar guys gets blamed and so he should if he is guilty of ignorance. Pool builders need to learn to respect the territory of the solar installer. These days a solar installer has to be responsible for what he installs so he has to follow manufacturer's recommendations. Solar pool heaters need to be designed. In this industry the big players have no standards. They have specs and those specs are surely called on in the event of a major warranty hassle but those specs are not understood by their people in the field. We're writing the book on this. If the pool has infloor cleaning we need somewhere else to deliver the solar heated water. We need a separate pipe to the pool or if its a pool/ spa combo a separate pipe to the spa. Usually there are other inlets to the pool that we can utilize but sometimes not. Think about what makes sense here.

My own personal pool mechanical design premise is that all pool design should start from the idea that the pump needs to be sized right. What has happened historically is that pumps have always been oversized just to be sure. Filtering, solar, salt water, ozone, and vacuuming all require minimal power. 3/4HP is plenty on any residential pool. In floor cleaning, spa jets, waterfalls all require much higher power and should all be on a separate higher power pump that only runs when one of these features is activated. Infloor cleaning would need to have its own filter to accomodate my pool mechanical design philosophy. That adds cost and takes up space so that is no good but I truly believe that if a pool builder simply took 5 minutes to sit down with the customer and give him some choices he'd not only upsell to the better arrangement he'd also eliminate the chance that any of his competitors would win the customer's confidence. In the two pump scenario the job of the solar designer is easy. We just tie in after the filter and divert the flow to solar and return the water before the gas heater. Its Figure 1a in the installation manual you can download at www.h2otsun.com off the navigation bar at the left. The two pump idea never flew well so most pool spa combo pools we run into are single pump systems and that pump is oversized and now that electricity cost (and global warming) is an issue people aren't happy about what the pool company did to them. The retrofit solution is the variable speed pump. In solar /filtering mode the speed is low and electricity cost is low and the pump runs all day quietly. When a higher speed function is called for solar is off and isolated from the pressure by the seals in the 3 way valve as well as the return line check valve and the higher speed kicks in along with higher pressure and everyone is happy..... until the check valve or the 3 way valve leak...We need a failsafe so what we use is a spring loaded check valve. If pressure ever goes too high it'll exhaust water and let you know there is a problem. This is a perfect lead in to my next article which I promise will be a lot more interesting and contemporary. Understanding pressure and flow as it relates to solar design in these first two blogs is absolutely critical. Once you understand what causes pressure and how to solve pressure issues you can tackle any pool mechanical design issue you come across and its really smart to do that before you start adding solar heaters with hundreds of extra feet of plumbing and thin black tubing all over the customers roof. Somebody has to look at the big picture and the pool builders haven't done it in the past so we have to. The situation is entirely different when dealing with commercial pools. There we have design employed. Not so in residential.

Pool Mechancial Systems and Solar Pool Heating

2010-04-09T13:31:00.000-07:00

Ken Wright is president of Hot Sun Industries Inc, a San Diego based manufacturer and distributor of solar swimming pool heating technology. This blog chronicles the ongoing struggle of one entrepreneur and his noble staff attempting to take a technology approach to solar pool heating…..technology in concert with a swimming pool industry sometimes set in its ways. Hot Sun’s main web site is www.h2otsun.com Welcome to our blog. I trust you'll find our experiences in the field worthy of publication.

Since many of my readers will be our solar dealers looking for on-going training and many solar energy people have no specific swimming pool knowledge it is necessary that we first cover some of the basics of how swimming pools normally work. We all know that a pool mechanical system in its simplest form consists of a pump drawing water from the skimmer baskets and the bottom drain, pumping the water through a filter and returning it through "inlets" to the pool. Its normally all plumbed up with 2" and 1.5" pvc pipe. The pump runs long enough each day to theoretically turn the water over at least once a day. On commercial pools where the health department oversees things generally the requirement is that pools are turned over once in 6 hours. Filters are either sand, cartridge or diatomaceous earth. Sand filters are my favorite. They restrict flow more than the others but they are simpler and easier to clean. "Backwashing" is running the pool water backwards through the filter dumping dirty water to drain. Cartridge filters use a removable paper cartridge so the restriction is minimal when the filter is clean but cleaning requires removal and manual work with a hose. DE filters (diatomaceous earth) are just cartridge filters with a special compound packed in so that the water is treated with the magic earth. These filters also boast of finer particle filtration. Its all nonsense as far as I'm concerned. The job of the chlorine is to oxidize the contaminants into particles that can be filtered out. Pools with sand filters are every bit as crystal clear as pools with DE as far as I could ever tell but then again I've only visited about 15,000 pools in my career. Pool service guys have spent their careers dicking around with this more than we have so if they say DE makes sense in your area I defer to them.

Historically it has been the case that the pool construction industry hasn't been at all concerned with pool pump electricity operating cost. The pool builders are excellent tradespeople. I don't know how to build a pool any better than they know how to configure a mechanical system taking into consideration pressure and flow. Pool builders should not be insulted when an engineer or someone qualified tells them that all they need is a 3/4HP pump for filtering a residential pool but they are. The pool industry is missing oversight. There are no engineers. If I was the engineer working for a major pool company i would specify 3/4 HP or 1/2 HP as the filtering pump power on every pool. My job would then be done because there isn't anything else that requires a mechancial engineering degree. Everything else is pretty much OK just handled by the trades.
Seriously. The idea that you need 1.5HP to filter a residential pool is bordering on the insane. I still fight with pool builders to this day over basic pool pump sizing. Title 20 law in California (Jan 2008) has gone a long way to solve this problem for me by not allowing more than 3/4HP by law. Its a good law. How else can you get past widespread industry misconception? To be fair its just that energy is cheap so why bother trying to save any of it. If one aspirin cures your headache then take 5. That's the thinking and it isn't always the pool builder's fault. He's just not trained to argue it. Energy conservation has only been on the average guy's radar now for a few years.

I spent the first 24 years of my career as a solar pool heating technician, installer, dealer, distributor, manufacturer and consultant spending far more time than I even intended every single day fighting with pool builders over pump sizing. Over my career I saw pool pumps go from 1/2 or 3/4HP to 1.5 or 2 HP on the exact same size pools. The older pools have no trouble staying clear. Its all in the chemistry. Keeping the pump on all day means controlling the chemistry, the scum lines, all day instead of just for the 3-6 hours you end up running a pump if it is oversized. Oversized pumps are noisy because they are oversized. Oversized pumps are expensive because they are oversized. They cost even more to operate than they should usually because they are forcing water through piping not sized large enough for the high power. They fail sooner because of the extra stress from the extra pressure and of course from the solar person's point of view, the pressure is the absolute worst thing you can introduce into a solar heater.

A solar pool heater is a large thin plastic heat exchanger with the sun. When the pool is up to temperature (think hottest time of the year mid summer) the collectors bake in the Hot Sun and the pressure doesn't disappear in every case just because water is diverted away from solar. www.h2otsun.com/pools is a valuable lesson in pressure and solar design to get around pressure. Stagnation temperatures can reach 185 degrees F in the desert. Even in Canada we've seen collectors hit 180F in stagnation. These temperatures are too hot for the pvc pipe the systems are plumbed in and when I say systems I don't mean the solar systems, I mean the existing pool systems. C'mon everyone, let's be real. If you blast a solar pool heater with 30 psi you're asking it to do the job of metals and you can't change the pool plumbing to all copper and you wouldn't want to anyway. We are the only solar company on the face of the planet...except our competitors at Sunbather in Australia that I know of, that accept that we need to avoid collector pressure when solar heating swimming pools. Oh, the big competitors doing millions of dollars a year in sales know it but they are smarter than me. They know that introducing this into the equation requires a lot of extra work and extra training on the part of their dealers. They may have tried but in the end its just not worth the bother. The name of the game is sales not physics lessons. Leave the problems for the pool service industry and keep life simple for the salesmen who boldly install solar and pools faster than they can say, "Will that be cash or charge?" Just sell the damn stuff damn it. I'm being fecicious. I truly believe that there is room in the world for a technology approach to a technology like solar pool heating and I will spend the next half of my life proving it. This blog is the beginning of how we will educate the world on this subject.