Talk:Solar water heating

Pictures

Can you please put more pictures in this article? 130.49.162.62 19:32, 29 October 2006 (UTC) williamsharkey at gmail dot com

Link to buy solar hot water heaters.

Here is a link to a great solar hot water heating site http://www.solarroofs.com/Makingitbetter7 06:34, 15 December 2006 (UTC)

hi. i read your article about solar panels and everything.. but i was wondering if you would add about the financial cost to produce the energy, the enviormental impactss, if it is renewable or nonrenewable, and last of all the availability of this source of energy. hopefully i did not ask too much?

The link is not necessary for the article, it may be seen as extra/free advertising. I think a general sentence describing said web sites would be more appropriate. TacoEditSquad (talk) 02:01, 17 October 2017 (UTC)

Image request

An schematical image is to be added to the article to make things more clear. At *Solar hot water system schematical picture and especially at another schematical picture of a solar hot water system (page 22), there are 2 good pictures. Is it possible to upload them at the top (where the "no picture available" is located ?

These pictures are incorrect - please refer to link on picture and associated comment.

I dont know whether the picture may be taken from the brochure and simply modified with a program (GIMP, ...). Perhaps that this is possible and legal (OND Vlaanderen is a governmental information company) and that the picture may be thus modified and uploaded at a legal way.

KVDP (talk) 15:12, 9 February 2008 (UTC)

Name change

I believe that "Solar water heating" would be a more appropriate name for this article. --213.149.123.28 (talk) 23:11, 13 February 2008 (UTC)

DIY Solar Hot Water Systems

With ever rising diy-community and their increasing environmental awareness, people have begun building their own (small-scale) solar hot water systems from scratch. Trough the internet, the community is able to attain plans to solar hot water systems. and people have sprung up building them for their own domestic requirements. The DIY-solar hot water systems are being used both in the developed world, as in the developing world to power homes.

I'm already putting this section in, hope it qualifies (it would be very helpful for the green community so try to improve it before deleting it, if you were tempted to this. KVDP (talk) 12:18, 18 February 2008 (UTC)

References

Link to obtain extra info and pictures, ...

• Dutch Useful publications on solar hot water systems with drawings and explications of practically set-up systems). Notable publications with pictures include: "Zonneboilers - warm water met de zon", Ideeen voor energiezuinig bouwen (useful picture hot water solar plate and tank), "Energieprestatieregelgeving: Praktische gids voor als u binnenkort gaat bouwen of verbouwen (pricing commercial hot water systems + installation by third party)"

Another useful schematic is present in this document (page 22)

See to the links mentioned, include info in article. KVDP (talk) 10:05, 30 March 2008 (UTC)

I also added extra info in article:

According to ANRE (a Flemish energy agency, subsidised by the Flemish or Belgian government , an complete, commercial (active) solar hot water system composed of a solar collector (3-4m²; this is large enough for 4 people), pipes and tank (again large enough for 4 people) costs around 4000 euro. The installation by a recognised worker costs another 800 euro.

If not up to standards, please improve it and make sure the info remains available.

Thanks. KVDP (talk) 12:11, 30 March 2008 (UTC)

References

Batch water heater picture

A picture of a batch water heater would be useful here. I saw a very nice one at the book "Earthship volume 2", but this one is useful too. —Preceding unsigned comment added by 81.246.142.204 (talk) 13:50, 28 August 2008 (UTC)

Schematic

Someone removed the schematic and upped other picture. As the first was useful with this other one (included operation within a house with extra components, I reuploaded :

Schematic of an active solar heating system

Do not remove; lots of cooperative work has been gone in this (I spent lots of hours on it too). Thanks;

KVDP (talk) 16:49, 28 August 2008 (UTC)

Tax Credits

Any information pertaining to the incentives for using solar hot water should be expressed fully.

although wiki is not a collection of links it is visited by many people each day to learn about this wonderful world of ours.

informing people is what wiki is about right?

Reference list

This list has dead links, how can I edit these?

See which one it is and search and modify in text, do not edit anything under references itself.

Pictures

The pictures at http://www.appropedia.org/Solar_hot_water_-_system_types (Examples of Common Solar Hot Water Systems) can speficiy the difference between open and closed loop active systems. Please include in article.

Also, can someone improve my batch heater (

) and upload to article again —Preceding unsigned comment added by 81.245.182.116 (talk) 16:06, 11 February 2009 (UTC)

Unglazed equals flat plate collector ?

Is a unglazed collector a flat plate collector. If so, add this article to text:

Also add following images where applicable: Image:Evacuated tube diagram.jpg Image:Active_closed_loop_solar_HW_system.gif Image:Active open loop solar HW system.gif

A text explaining the difference between the open loop and closed loop systems should be added. Some info can be found at Appropedia-system types —Preceding unsigned comment added by 81.245.168.190 (talk) 10:36, 12 February 2009 (UTC)

Solar water systems comparison

The comparison at http://njwolf.iweb.bsu.edu/solarhotwater.htm can be integrated to page. Also, recategorise the page, for example drainback systems are a very important category spanning over some of the mentioned (uncategorised) systems on the page. Some additional info is available at http://www.house-energy.com/Solar/System-Drainback.htm —Preceding unsigned comment added by 91.176.218.77 (talk) 15:58, 7 September 2009 (UTC)

In the article, there is talk that solar water heating system can be classified in different ways:

   * The type of collector used (see below)
   * The location of the collector - roof mount, ground mount, wall mount[29]
   * The location of the storage tank in relation to the collector
   * The requirement for a pump - active vs. passive
   * The method of heat transfer - open-loop or closed-loop (via heat exchanger)
   * Photovoltaic thermal hybrid solar collectors can be designed to produce both hot water and electricity.

This is totally confusing and in some way actually wrong aswell; there is only 1 good classification method, namely passive or active systems, which are divided into eg drainback system, non-drainback systems, and then divided again to the type of collector. Please clean up and simplify this article based on this info —Preceding unsigned comment added by 91.182.201.92 (talk) 08:36, 8 September 2009 (UTC)

Image

Added this image:

A thermosiphon solar hybrid system

Linking to External Sites

Earlier today, I added a link to a new company that I'm working with called Zoe Energy (www.zoeenergy.com). The company just started about 2 weeks ago and is planning on including discussions surrounding alternative energies. I think it would probably be useful to Wikipedia to include linked to this "type" of site. Rangerwez (talk) 19:11, 10 September 2009 (UTC) rangerwez

Please don't add links to companies that you're working with, see the conflict of interest guideline. Even setting that aside, commercial sites are usually not going to be linked. See the guideline on external links. - MrOllie (talk) 19:18, 10 September 2009 (UTC)

Incorrect information re passive direct heating systems. The statement that passive systems leak heat by backsyphon at night is incorrect. When the panel temperature drops below that of the water in the tank the water cannot thermosyphon downwards. This is a physical impossiblity. Only if the water in the tank/ cylinder is colder than than of the panel will this occur, as per normal operation. This information should be removed from the article. Comment by Ekogaia.

Solar Thermal Collector subsumes Collector section here

I propose we merge the collector section here into Solar thermal collector and reduce this section to list (and link to) the types of collectors that are used for heating water (as opposed to producing thermal electricity).Jojalozzo (talk) 15:55, 22 January 2010 (UTC)

I have cleaned up a lot of information towards the bottom of the current page, allowing the Solar Thermal Collectors section to be moved over to the article on solar thermal collector. I think the paragraph on solar thermal cooling should also be removed. I included a reference to the appropriate page on solar thermal cooling in the introductory paragraph of this page. Will you be prepared to do the move of the material to the Solar Thermal Collector article? Willemferguson (talk) 18:38, 13 February 2010 (UTC)

I am not clear on what needs to be moved. The Solar thermal collector article seems to have a lot of material already. If you have time please check to see if the info on Solar thermal collector needs any of what's here added. Jojalozzo 20:45, 13 February 2010 (UTC)

Indirect active system image sensor location

These new diagrams while excellent otherwise have the low side sensors detecting the return temperature on the heat exchanger. In my experience the sensor for the low side of the differential controller is placed in the storage tank near the heat exchanger to detect the temperature of the potable water at that location in the tank. Jojalozzo (talk) 13:57, 7 February 2010 (UTC)

Check out the schematics at: http://homepower.com/basics/hotwater/ I can easily adjust the diagrams if it is necessary. Please let me know. Jwhferguson (talk) 22:29, 7 February 2010 (UTC)

I see the homepower diagrams agree with you but the text further down the page says "The differential thermostat controller compares heat sensor readings from the storage tank and collectors and switches the pump accordingly." That would imply that the sensor should measure the storage tank temp not the heat exchanger exit temp. Have you seen the sensor located on the heat exchanger exit? I have not but it probably does work ok but with somewhat different controller settings. Jojalozzo (talk) 22:49, 7 February 2010 (UTC)

We use direct systems almost throughout, so I have no experience with indirect systems. I will change the diagram. In the final review of the text when I am done with what I initially intend to add to this page, I will see that an expert revisits this aspect. ok? Hope I am not insulting you when I talk of an 'expert' in the last sentence, maybe you are an expert yourself!! Jwhferguson (talk) 05:57, 9 February 2010 (UTC)

Sounds like a good plan. Jojalozzo 20:52, 9 February 2010 (UTC)

I see you made some changes and apologize for harping on this but the tank-mounted sensor usually measures the temperature near the heat exchanger since that tells the controller what the delta T will be where the heat transfer occurs. Jojalozzo 02:57, 15 February 2010 (UTC)

That's exactly where I would have put it if I were to mount a sensor in the tank. Will do. However I am out of town for a while with no good internet, so please have some patience with me. I am getting towards the end of my endeavour with this article. I am looking to have it reviewed by an expert around April. Want to improve referencing. 41.244.49.69 (talk) 20:17, 15 February 2010 (UTC)

History of solar water heating in Israel

This section is unnecesary and undue weight. Perhaps a new article can be created with it? LK (talk) 10:35, 11 February 2010 (UTC)

Israel

Levi Yissar built the first prototype Israeli solar water heater and in 1953 he started NerYah Company, Israel's first commercial manufacturer of solar water heaters. Despite the abundance of sunlight in Israel, solar water heaters were used by only 20% of the population by 1967. Following the energy crisis in the 1970s, in 1980 the Israeli Knesset passed a law requiring the installation of solar water heaters in all new homes (except high towers with insufficient roof area). As a result, Israel is now the world leader in the use of solar energy per capita with 85% of the households today using solar thermal systems (3% of the primary national energy consumption).

Solar water heater on a rooftop in Jerusalem

Israel's use of solar water heaters is estimated to save the country two million barrels of oil a year, and the country has the highest per capita use in the world. In the 1950s there was a fuel shortage in the new Israeli state, and the government forbade heating water between 10 p.m. and 6 p.m. As the situation worsened, engineer Levi Yissar proposed that instead of building more electrical generators, homes should switch to solar water heaters. He built a prototype in his home, and in 1953 he started NerYah Company, Israel's first commercial manufacturer of solar water heaters. By 1967 around one in twenty households heated their water with the sun and 50,000 solar heaters had been sold. However, cheap oil from Iran and from oil fields captured in the Six Day War made Israeli electricity cheaper and the demand for solar heaters dropped. With the 1970s oil crisis, Harry Zvi Tabor, the father of Israel's solar industry, developed the prototype solar water heater that is now used in over 30%-40% of Israeli homes.

In 1980, the Israeli Knesset passed a law requiring the installation of solar water heaters in all new homes (except high towers with insufficient roof area). As a result, Israel is now the world leader in the use of solar energy per capita (3% of the primary national energy consumption).

As of the early 1990s, all new residential buildings were required by the government to install solar water-heating systems, and Israel's National Infrastructure Ministry estimates solar panels for water-heating already satisfy 4% of the country's total energy demand. Israel and Cyprus are the per capita leaders in the use of solar water heating systems with over 30%-40% of homes using them.

I do not agree at all.The historical importance of Israel in developing and implementing solar thermal devices is undisputed. The historical context would be incomplete without a section on Israeli technology development. Their skills have been exported to many other countries. However, your point about weaknesses in the text has merit. I have shortened the Israeli section, reorganised the HISTORY section, hope this improves the content. Jwhferguson (talk) 18:57, 11 February 2010 (UTC)

References

Solar collector performance table

The table comparing different collectors in Economics, energy, environment, and system costs presents some problems:

1. The table is an advertisement for manufacturers and may violate WP:SPAM.
2. It may grow indefinitely as editors add more collectors.

I propose we pare it down to the essential and

1. eliminate the names of the manufacturers and the countries of origin
2. use a range of values instead of specific values
3. cite one or more third party comparisons so we do not need to mention the manufacturers as the source of the data.

Jojalozzo 15:02, 9 March 2010 (UTC)

Good point. Done. Strictly speaking, the SRCC in the USA is a private company. However, it is by far the best known international certification system used world-wide. Hope it does not violate WP:SPAM. Looks more acceptable now? Willemferguson (talk) 18:12, 10 March 2010 (UTC)

SRCC is a good independent third party for ratings. However, the SRCC site does not appear to be the source of much of the data in the table. The units don't match SRCC units and there are rows that don't seem to have their equivalent on the SRCC site. I don't think we should include data that is published somewhere else without saying where it came from. Also I think we should include only data that is available for all the collectors. Jojalozzo 19:28, 10 March 2010 (UTC)

Have replaced the table. All figures come directly from SRCC certificates of systems, except the bottom two lines that are calculated directly from information on the certificates. I use slightly different language here than the certificates since the Joule is most often used as a unit of mechanical or heat energy while the Watt is the standard unit used in electricity (in this case for comparing with equivalent electrical water heating devices). Is there a sensible way to do referencing here? Willemferguson (talk) 19:08, 11 March 2010 (UTC)

• I think we could reference the SRCC data pages without mentioning the manufacturers. Something like

<ref>{{Cite web

|url= http://securedb.fsec.ucf.edu/srcc/coll_detail?srcc_id=2004013A

|title=SRCC flat plate collector data

|work=securedb.fsec.ucf.edu

|accessdate=March 11, 2010

}}</ref>

• Does it matter how many tubes there are in the tube collectors?

Jojalozzo 01:27, 12 March 2010 (UTC)

Since evac tube systems are sparse (i.e. the active absorption area is often quite smaller than the collector area) it is often difficult to judge the real absorber size of the collector array. Evac tube systems vary tremendously in size, in sizes of 10,12,18,20,24 etc tubes. Giving the number of tubes is a way of giving an (qualitative) idea of the absorber area involved. I still need to format the references in the table following your suggestion. Thanks. The most important activity for this article now is probably looking at the referencing. —Preceding unsigned comment added by Willemferguson (talk • contribs) 07:40, 12 March 2010 (UTC)

I disagree. Evacuated tube collectors are rated with absorber area carefully measured. We have a table row just for that already. The number of tubes tells us little or nothing about absorber area or anything else about production. The width of the absorber and the spacing between them varies between collectors so tube count indicates little if anything about production or efficiency. Jojalozzo 21:36, 12 March 2010 (UTC)

Why is the absorber size data equal to the overall size in this chart? It's not at all accurate. At best, we could average the ratio of tube size to overall size and at worst, we could leave those cells blank. As it stands, they seem to be ruining the calculations in the lower rows. As for the tube number suggesting absorber area, I believe manufacturers keep their spacing consistent and simply spread more tubes out across a wider frame. Jayarmstrong (talk) 21:04, 11 April 2017 (UTC)

By the way, I think you've done a good job with this table and the rest of the article. I apologize if my concerns are not worded so it's clear they're aimed at improving the article in a collaborative manner and are not meant to detract from all the work you have been doing. Jojalozzo 03:39, 13 March 2010 (UTC)

Remember my main aim is to write this article in a way to make useful information available to the man in the street who has no particular technical knowledge. Therefore the attempt to steer away from units such as Joule or BTU and rather use Watt, an electrical unit well-understood by many lay people. Same with the inclusion of tube data in this table. The man in the street is confronted by a company that wants to sell him a 10-tube or a 30-tube system. He is not really aware of the real technical parameters e.g. the aperture area of the collector. But the number of tubes makes sense to him because it is a basic characteristic of the system he (or she, if you pardon my sexism) is looking at. This is in particular a difficulty with evac tube systems. Therefore I have included this in the heading of the table. talk) 10:39, 14 March 2010 (UTC)

Is this table getting performance data for complete systems or collectors? I see some of the links are for pages about systems and one is for just a collector, but the SRCC system pages do not appear to have performance data, only the collector pages have that, is that so? Jojalozzo 14:47, 14 March 2010 (UTC)

Will check on the one that points to a collector. The table points to systems that have been certified, mostly with more than one collector. Remember a collector cannot be tested in isolation, but as part of a system. Many systems are certified with a range of collectors of different sizes. From these collectors that belong to a particular system I have each time chosen a collector with an aperture area around 2 m². But yes, you are right in that many of the technical specs ultimately come from the collector table. SRCC use a collection of data from both collector and system as input to a TRNSYS analysis. "Data from the OG-100 collector test, the system test and review of design and installation guidelines are input to a computer program called TRNSYS to calculate the performance rating" (http://www.solar-rating.org/certification/certification.htm#system). The OG-100 procedure supplies the data for each collector. Hope this makes sense. By the way, I suspect the data in the botoom 2 rows are overestimates, but this is what the math predicts. I hope there will be good opinion when we get to the expert review stage. Willemferguson (talk) 19:29, 14 March 2010 (UTC)

In my reading of the SRCC process, the collector rating is done separately from the system rating except for thermosyphon systems that cannot be operated in isolation. The collectors for active systems are tested in isolation but with pressures and flow rates of the designed system. I propose we use the SRCC's Solar Energy Factor (SEF) or, perhaps easier to explain Solar Fraction (SF), for each system and skip collector efficiency since it is problematic for thermosyphon systems. Jojalozzo 20:10, 14 March 2010 (UTC)

Can I suggest we leave this matter for expert review? I plan to involve someone from SRCC as an expert. 41.244.20.220 (talk) 21:32, 14 March 2010 (UTC)

Such an expert would be helpful at some point but I don't think we need an expert to make sure we have consistent links for each column and performance measures that allow the reader compare the systems (not the collectors). Jojalozzo 01:20, 15 March 2010 (UTC)

active/passive bubble pumping system

I am adding in a new type of pumping system I found on the web under active -- I am not sure if it would be better placed under passive -- although it does not use electricity to run the pump it isn't using convention as in a thermosiphon either....and is using a pump. Someone more experienced with solar thermal system - please make sure it is in the appropriate category.Enviro1 (talk) 13:54, 10 June 2010 (UTC)

HCF

The initialism HCF is not defined at its first use. Please clarify the meaning of HCF. - Ac44ck (talk) 00:33, 3 October 2010 (UTC)

Thanks to Jwhferguson for fixing the typo to HTF. -Ac44ck (talk) 06:54, 7 November 2010 (UTC)

Overheating

It has happened, with a number of solar water heating installations, that the water temperature rose to nearly 100 degrees C, during intense solar radiation and low hot water demand: High water temperatures caused plastic plumbing to rupture. This problem calls for methods of cooling the tank water when temperatures of about 90 degrees are reached. An easy way to do this is to force-circulate the tank water through a radiator device (similar to heating radiators) placed in a shady and well ventilated location. Care should be taken that the materials the radiator is made of be suitable for handling drinking water. Alternatively, the fluid of the heat exchanger, if such is used, be circulated through the radiator, but in this case electrically operated valves should be used to isolate the heat exchanger circuit from the solar collectors. —Preceding unsigned comment added by 62.38.220.132 (talk) 08:51, 28 March 2011 (UTC)

This will not happen in a drainback flat-plate system, and it is extremely unlikely that it will happen even in an antifreeze flat-plate system. However, if you go on vacation and have an ICS, ICS-thermosiphon, or a system using evacuated tubes, yes, it's possible that you could come home to a disaster. It sounds like you have a FAFCO antifreeze system, though, since it has "plastic plumbing" in it. At any rate, your system should be protected from this type of damage from the T&P valve, but people often neglect their T&P, leading to sometimes catastrophic results. My advice would be to replace your T&P valve since it most likely failed to do its job. (The other possibility is that your T&P is actually working, but your system failed long before the boiling point, which is possible, given that it is plastic.) SolarCoordinates (talk) 18:28, 15 April 2011 (UTC)

"Since the surface-to-volume ratio increases sharply as the diameter of a pipe decreases"

The choice of making flat-plate collector risers small has little to do with the "surface-to-volume" ratio, and is instead based upon (1) shortening the distance between the absorber fins' center point and the riser pipe, as decreasing this distance increases thermal conductivity, reducing heat loss, and (2) the same size as the headers would cause uneven flow across the risers: the risers near the outlet would have much higher flow than the risers near the inlet. SolarCoordinates (talk) 09:23, 20 April 2011 (UTC)

April 20 Overhaul

I changed the article because, for example, the definitions of direct & indirect were buried in the "Passive Systems" section even though they are completely independent of passive/active. Freeze & overheat protection also had their own section under "Types of Solar Water Heating (SWH) Systems)" even though they aren't "types" at all. Changes were mainly structural in nature, but some content was changed as well. If you have any concerns about the changes that were made, PLEASE POST THEM HERE.

More changes will be coming since, for example, ICS is defined in two different places, and there is also a small "history" section under "Collectors used in modern SHW systems," which seems unnecessary. I am also not a fan of the "140 kWh per month" table, as that represents a mediocre system installed on a two-person residence, which should not be considered representative of a typical installation. Additional sections will be made to address concerns for future changes. SolarCoordinates (talk) 21:37, 20 April 2011 (UTC)

Financial data for Israel

Regarding the "Costs and payback periods for residential SWH systems with savings of 200 kW.h/month (using 2010 data)" chart: The following is updated data obtained in August 2011: Country: Israel Currency: NIS System Cost: 3,200 Subsidy: 0% Effective cost: 3,200 Electricity cost/kW.h: 0.52 Electricity Saving/month: 104 Payback period(y): 2.6

I would have put the data in myself but could not find how. 84.229.231.234 (talk) 19:20, 16 August 2011 (UTC)

Costs and payback periods table --> USD

Converting all of the costs to US Dollars (using 2010 exchange rates, same as date of data) would make this table much more useful. Any objections? — Preceding unsigned comment added by Markg729 (talk • contribs) 19:40, 10 October 2011 (UTC)

The text beneath this table draws false conclusions - the table does not take account of the amount of power generated per month, indeed it assumes a 200 kWh saving, meaning that it just compares the cost of installation and the cost of electricity. How much power can be produced in varying locations is not referred to at all.Pincinator (talk) 18:53, 23 February 2012 (UTC)

How Pool heating work?pool heating — Preceding unsigned comment added by 2.146.145.19 (talk) 13:24, 10 December 2011 (UTC)

Questionable Savings

Its should probably be pointed out that for most people the savings gained from installing a solar hot water heater are questionable at best. This is because most people use most of their hot water either in the early morning or in the evenings when a solar collector is not producing hot water. Let me elaborate. Lets say that all the members of your family shower in the morning, effectively using most of the stored hot water. Now, since the solar collectors have not yet heated up, the back up gas or electric heater will automatically come on and stay on until the entire 40 gallons in the water tank is hot again. By the time the solar collectors are ready to produce there job is already done. And if you shower in the evening it’s the same story, as the sun is going down by then. The only thing the solar collectors will be doing in this case is replacing the heat that dissipates from the tank during the day. The gas or electric heater on the other hand will be making ALL the hot water used by you and replacing all the heat dissipated from the tank during the night. So basically this means you could actually save more money by installing a tankless hot water system, which heats water on demand, than by installing a solar system. Of course if your family uses most of their hot water in the afternoon then a solar system could definitely save you a substantial amount on your hot water heating cost. I suspect that when the solar industry gives out statistic on potential savings they are basing those savings on these afternoon energy users, which of course is very misleading to the rest of us. Don’t get me wrong, complete home solar heating systems can be great, be they passive or active. They are usually able to store all the energy gained from the sun during the day and release it back into the house during the night. Solar hot water heaters alone on the other hand are probably a big waste of money for most people though. Slobeachboy (talk) 05:43, 21 January 2013 (UTC)

Great. WP:BOLD, cite it and write it! --Wtshymanski (talk) 14:44, 21 January 2013 (UTC)

The article could really be improved so that it's clearer why this is not a problem with a typical well-designed system! (e.g. systems with 2 tanks or 1 tank AND a tankless water heater) --Elvey^(t•c) 23:42, 24 April 2015 (UTC)

== Speaking of Questionable - Thermalux / Solar Energy Labs, Inc. idiocy ==

Wow, what an idiotic system: Use PV panels to heat water with the electricity generated. Yes, there's a company actually marketing such an idiotic solution! (Sure, it'll work, it'll just be very inefficient/expensive/under-powered compared to a proper well-designed system.) http://www.offgridquest.com/energy/wind-power/the-best-off-the-grid-water-heater-yet-a And they managed to get over $6000 committed to their kickstarter project. --Elvey^(t•c) 23:42, 24 April 2015 (UTC)

Doesn't seem to have attracted any news coverage other than this, so probably not appropriate to include yet. if it does, I bet it would make an amusing entry in the efficiency tables. --Elvey^(t•c) 23:47, 24 April 2015 (UTC)

Freeze protection list duplicate?

Low pressure polymer water channels made of silicone rubber is mentioned in both second and third type of freeze protection.

This seems to be fixed and replaced with appropriate listings. TacoEditSquad (talk) 02:05, 17 October 2017 (UTC)

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External links modified

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"kW.h"

What is meant by "kW.h"? This way of writing is not SI compliant. Please use a scientific valid notation. Did you mean kW*h? In that case I'm most familiar with seeing it written as "kWh". Since this is mostly accompanied by "/day" I would welcome a more simple and technical number like a peak performance in W. Also the preferred unit for energy should be the J. --BjKa (talk) 13:13, 27 January 2017 (UTC)

kWh is the preferred unit in this context. It is normally written "kWh", never "kW.h". Please feel free to remove the dot when you see it. The fact that the unit is so widely used in this context means that even when dividing by another unit of time (day) is still useful to keep kWh/day in most cases for comparisons. --Ita140188 (talk) 06:00, 28 January 2017 (UTC)

Comments about possible changes to consider

1. The information about "flat plate collectors" should have a citation about them being used in Florida. 2. It would be beneficial if in the DIY section the characteristics were more descriptive. Ex: Low maintenance is vague. Low maintenance could mean different things for different people. 3. Citation needed when discussing the durability of tempered glass in flat plate collectors. 4. In the evacuated tube section, is there any more information that could be added to explain why the vacuum life varies from 5-15 years? 5. When stating the cost benefits, the sentence: "In sunny, warm locations, where freeze protection is not necessary, an ICS (batch type) solar water heater can be cost effective." Sunny and warm are vague. Ex: some people may find 60 degrees to be warm while others say warm is 90 degrees. By being more specific about the exact temperature needed to keep the solar water heater cost-effective. This would erase any confusion.

Nathanwcampbell (talk) 19:04, 16 October 2017 (UTC)

Update

Can someone find any new technology as of 2017 to add to this article. I'm sure something new has come out in the last few years that would be pertaining to this. Such as how pricing for installing a system in the US is much lower then it has been. Article: https://www.homeadvisor.com/cost/plumbing/install-a-solar-water-heater/ TacoEditSquad (talk) 02:08, 17 October 2017 (UTC)

External links modified (January 2018)

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Width of table within the article needs to be increased

In my opinion, the width of a table within the article needs to be increased as the title 'Currency' has been split due to the text space not being wide enough, making the table look unprofessional in my opinion. Xboxsponge15 (talk) 15:24, 29 July 2021 (UTC)

"Coke Glass"? in Evacuated tube collectors section of article

Typically green tinted glass is called soda glass, not "coke glass" https://en.wikipedia.org/wiki/Soda%E2%80%93lime_glass

Optically clear glass needs the addition of some other elements, historically lead, for crown, crystal or leaded glass. Probably what would be important for a Evacuated tube collectors is transparency to infra-red, while absorbance is of import on the inner tube. The IR transmittance of plain old soda glass is awful. https://commons.wikimedia.org/wiki/File:Soda-lime_glass,_typical_transmission_spectrum_(2_mm_thickness).svg

2601:243:1202:D9F0:F854:B822:1A57:ED44 (talk) 02:48, 7 July 2022 (UTC)

Incorrect information regarding Evacuated Tube collectors.

While Evacuated Tubes are mentioned, only the outer tubes are described, with the assertion that water is passed through copper inner tubes. This is incorrect as follows: Within the evac tube is a copper tube, sealed at both ends and partly filled with a volatile liquid. The top of this tube fits into a socket in the water header, which is thermally insulated. Heat entering the tube evaporates the volatile liquid, which then condenses at the header and runs back down to complete the cycle.

This functions as a highly efficient heat pump: even on hot days the outer glass of the tubes remains notably cool. But perhaps most relevant, since there is no water in the tubes and the header is thermally insulated, there is no need for anti-frost measures in areas experiencing mild frosts.

It should also be noted that, while conventional flat plate collectors are significantly affected by lower ambient air temperatures and/or wind, evacuated tubes suffer very little thermal loss, offering much better year-round performance in temperate climates.

Further worth noting, and since evac tubes are exposed on both the upper and undersides: if the tubes are mounted raised from the from the roof, they capture not only direct solar heat, but also radiated heat from the surrounding roof. IBobSolar (talk) 00:04, 27 July 2024 (UTC)