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solar heat

Posted by mudbugtx (My Page) on
Wed, May 26, 04 at 11:40

Been interested in this for a couple of years, but don't know of anyone with experience on the subject. I was thinking maybe it would off-set my heating bills in the winter. Since Texas winters are relatively mild it wouldn't take much. Any thoughts or personal experience?

Here is a link that might be useful: solar wall heater


Follow-Up Postings:

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RE: solar heat

Solar heating is something I've recently been quite interested in. I've been looking at building a house, but it's unlikely to be a large house and many of the renewable energy systems are either expencive or need a lot of space. Solar heating of air (water systems are far more complex and expencive) is however affordable, reliable and compact. I'm confident heating would be the largest user of energy in the house, but solar heating could drastically reduce it during the day.

Here in the UK we use the heating often due to the cold weather, which is one of the reasons solar heating is high up on my list of must-have items for the house. Without a doubt, it would pay for itself in just a year or two and continue to save a large ammount of cash for decades. However, I have concerns about it's pay back time in Texas, somewhere that I assume has short winters that don't get very cold? You should work out the cost of your annual heating, and then the ammount that would be replaced by solar before investing in a solar heating system. It's impossible to be exact with a figure concerning so many variables, but a ballpark figure can tell you if it's worth the money.

You might also be interested in this link:

http://www.cleardomesolar.com


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RE: solar heat

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There was a solar water heat collector made ~ 20 years ago . .. don't know the reason of the company's demise . .. . called the Solar Cricket. An incredibly ingeniously simple design . . . . COMPLETELY passively driven . . very low tech and therefore virtually nothing to go wrong. It was basically a very well designed and implemented thermosyphon . . . . the ONLY moving part was a check valve. No pumps, sensors, or the like. Used a mixture of alcohol and water; which not only keeps it from freezing in colder climes at night; but also allowed for a lowered boiling point of the fluid as it operates under a partial vacuum. Just as your radiator on your car operates under INCREASED pressure ( which raises the boiling point of the mixture ), by operating under a partial vacuum this setup allowed for a lower boiling point. This boiling action is what "powers" the system . . . no pumps! It also self-regulates; that is when the sun goes down the system simply slows and eventually shuts off since there is no longer any thermal differential to drive it. You can look for it in Google; there are still some hits out there on it. I happen to have one of the original brochures . . . . can copy if anyone is really interested . . . just email me.

I am planning on building one in the not so distant future . . . . being an engineer; it's utter simplicity always impressed me. I'm in central New York state; and while it may not do much for heating a place up here; it can certainly "pre-heat" my water before going into the water heater. In the summer here; it could surely handle most of my hot water needs . .. .

Bob


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RE: solar heat

Bob, if you are looking for a newer, more complex version check out the site I attached. I know a guy who has one set up, even in -40 weather it is still pulling off 140 F water in full sunlight. The vacuum in the tubes allows for very little heat loss. I am incorporating 2x30 tube solamax arrays in a house I am constructing this summer.

I have no idea if there are similar products out there, but this is one I am familliar with.

chief

Here is a link that might be useful: http://www.solarthermal.com/


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RE: solar heat

Here is another couple of url's about solar thermal for water and space heat using Coaxial Vacuum Tubes or CVT;s.--------
Well now I have been warned of the perils of not allowing the profit makers from their graft. So the url's are not here, but suffice to say the solar bang for the buck is greater for solar thermal than PV by far.
Why is there a optional link box at the end of this posting panel if busineses are not allowed? Even .orgs have agendas of profit for someone.


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RE: solar heat

here is a site that can answer lots of questions and it is great

I once again have to give GAry thanks for putting this together

Here is a link that might be useful: builditsolar


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RE: solar heat

We are looking into this as well. It seems that open loop designs are not as efficient as closed loop designs and therefore are only used on commercial / industrial buildings and not homes.

I received one quote for a closed loop design but it would cost me $3,000 which is surprising as it is as you say a rather simple design, only heats up to 1,200-ish square feet and can only provide heat during the day when our large south facing windows already let lot's of sun in the house. It's far colder at night which is when I would want the most help with the furnace.

Then again, with the spiking of natural gas this year to more than double the past average $13 per MMbut, the finanial payback is certainly looking more viable.

But we'll keep looking and seeing what we can find.
Dan


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RE: solar heat

You probably use AC enough to make a heat recovery unit on your AC the device of choice for domestic water heating. Free hot water and a 10%-20% increase in AC efficiency.


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RE: solar heat

Dan, you can try to increase the thermal mass of your dwelling, get a few big fishtanks and keep goldfish or koi (you know you would love a 600 gallon tank in your living room wall) that way you can hold onto some of the heat from the day and some of the cooling from the night, not a good choice for 1,200ish SqFt however.


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RE: solar heat

My wife would love the fish tank! She had one when we were dating and our first few years of married bliss, but in our many, many moves it got left behind.

I came across information from one of our blogs sponsors (for full disclosure) about solar radiant heating over the weekend. He mentioned it before to me but I never gave it a second thought because we just put down nice hardwood floors in our dining room, kitchen and family room and I 'assumed' (yes, I know what they say :-) ) one would have to rip out all the floor to install radiant heating.

However, I was speaking with someone from another company and she was saying that you don't have to do that; i.e. for a retrofit the installer can simply install the radiant heating for say a main floor from the basement by placing the coils (if that is the right word....I'm still very, very new to all this) within the basement ceiling of an unfinished or a drop ceiling type of basement.

Does anyone have any experience with solar radiant heating? Does it really work? What is the financial payback like? Would one also need a solar air space heating unit to heat the basement if one installed a solar radiant heating system for the bungalow's main floor?

The initial material I have seen states that radiant heating also does not dry out the house as much as force air heating of any type. Is that true?

Yes, we live in Canada where it can get cold every once in a while.

Lots of questions I know. Thanks for the responses.
Dan


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RE: solar heat

"Does anyone have any experience with solar radiant heating? Does it really work? What is the financial payback like?"

I don't know about solar radiant heating. I have radiant system in place heated by a Bock oil water heater and have been looking at using a solar water heater in line to heat both DHW and Heat while using the oil as a back up system.

"Would one also need a solar air space heating unit to heat the basement if one installed a solar radiant heating system for the bungalow's main floor?"

You would zone off each section to your house. The basement could always have radiant tubbing installed on top of it and then have cement poured over it if you have the ceiling height. Here is how this guy did it; http://www.arttec.net/Solar/6-25/July25.html

http://www.radiantcompany.com
http://www.radiantec.com


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