Solar radiant Heat

[philbuilt]

Has anyone installed one of these systems?
I pulled the trigger and will be posting the process if there is any interest.
I thought about the out door wood boilers But I don't have much wood on my land.

The tractor portion of this project was digging the 70' trench to the panel mounts.

Here is the thought process.
I already have a cold fire oil furnace. Fuel last year $3700.00 May07-08
cost have gone up.

Wood stove: I would have to buy wood and cut, spit,stack and store.
( I already don't have enough free time)

Geo thermal: Very cool plan but the heat pump will need more electricity again additional cost per month.

Pellet stove: very popular here in Maine but again, Purchase of consumables and storage needed and feeding the system.

So my first thought was to reduce the amount of energy required to heat the house. I currently have baseboard heat. this requires the furnace to heat the water to 195-215 degrees. So after some research Radiant floor heat only needs to be 75-90 degs. This would be a savings by lowering the water temps. (hopefully 20% savings) So I will retro the house to radiant floor heat.
This alone I hope to save on heating because of the lower water and room temps. (warm feet warm body)? so I have read.

OK now for the solar part. There is a company in Vermont that specializes in radiant heat for the DIYer. This is where I also would add the solar Panels. I called and worked with them and decided to do this. The panels will heat a 120 gal tank.

So there is the setup any interest?
Phil

 

[RichNJKubota]

I installed a solar hot water heater last fall. The collectors are evacuated glass tubes. Four collectors with a total of 110 tubes and they are made in China. They produce water at high temps. We have two 60 gallon solar hot water storage tanks. Last winter I turned off one of the tanks so the remaining tank would come up to temp (170F) faster and there would be excess hot water from the collectors to heat the house.
I installed a radiator (looks like a car radiator) in the air handler for the house heat. When the 60 gallon tank is up to temp the hot water gets diverted to the radiator and it heats the house. It works great.
But I wonder why you think you'll need less heat if you go radiant vs. hot water baseboard? If your house needs, let's say 100,000 BTU per hour at 0F outside temp, then does it matter whether it's radiant or baseboard? Or am I missing something?

 

[EddieWalker]

I'm very interested in any sort of energy savings. One thing that always concerns me is the amount of upfront cost, versus the actual savings and how long it takes to make up the difference.

JLC had an article last month with a list of things people do that they think will save energy, but cost so much to do that it's not a savings at all. Having new windows installed was one of those things that costs so much to have installed with only a limited amount of savings that it takes 20 to 30 years to break even. I have a client who had done that first, then they had a front door installed with hopes that it would cut down on their bill, it didn't make any difference.

I had remodeled their bathroom and when they asked me what to do, I told them to add allot of insulation to their attic. I brought it up to 12 inches, which gave them an instant 30% reduction in their electric usage.

Not living in a cold climate, I can't imagine what it takes to heat a house. We use two space heaters to heat our home. We cut our electric bill by $100 per month by just heating the living room with one or two of those space heaters.

I've been thinking of either replacing my water heater with propane, or adding a loop that will pre-heat the water going into my water heater. The pre-heating method would be the cheapest, but so far I'm still stalling on trying this.

Hopefully I'll see something in your setup that I can use in mine, or at least get some ideas for more energy savings.

Eddie

Oh yeah, the weather stick starts out every morning in the down position, then works it's way up during the day. It doesn this every day and has been great fun to see where it's at. It doesn't work here with our humidity, but jus the fact that it moves so much is amazing!!! Thanks

 

[Willl]

the weather stick

 

[therebarely]

Interesting post, because I spent almost $4,000.00 on propane last winter, and froze to death It's time to do something. I saw an article a few months ago in Mother Earth News about a home in Idaho. The owner built a shed/garage with a passive solar collector on the south side, and pumped the warmed water through his furnace in the house. I am going to try to duplicate it to some extent, probably next year. In the mean time, I am going to install an outdoor wood furnace this fall through the existing duct work in the house. I bought it as a closeout in April, so the expense was minimal (as compared to $4,000.00 for propane). Any ideas would be greatly appreciated.

 

[thunderworks]

But I wonder why you think you'll need less heat if you go radiant vs. hot water baseboard? If your house needs, let's say 100,000 BTU per hour at 0F outside temp, then does it matter whether it's radiant or baseboard? Or am I missing something?

I have no technical expertise, only anecdotal experience. I built a new home 3 years ago and used radiant floor heat (geothermal heat source in my case). I am a very cold blooded person, normally hunkered down by a wood stove all winter. My wife convinced me to eliminate the wood stove, and heat the floors instead. Her argument, which I now believe, is that by heating the floor mass, which retains heat, you need to input fewer btu's, simply because the floor is essentially acting as a heat sink, retaining the warmth. The longer it's retained, the less frequently you input new btu's to maintain a comfort zone. I also believe that when floors are warm, your respond differently physiologically to the sensation of warmth, and really need less to be comfortable. I can't document squat about my opinion. . . . simply my opinion after 3 winters in thenew home.

 

[philbuilt]

RichNJKubota,
I looked at the tube as well. When I compared the overall performance the tubes only use 60 % of the space for producing heat. The panel that I ordered are 96% usage.

Eddie,
I was thinking that this would be a great setup for the showers at your camp ground. You guys heat in the winter?
I,m glad the weather stick is still working. I thought that perhaps the termites would eat it like it was imported candy.

Will,
Do a search for Maine weather stick.

therebarely,
I had come across the same article I believe. The guy built a shed with a homemade water tank. Is that the one? That was what got me going one this quest.

thunderworks,
Thank you that is just what I want to hear. My basement maintains a temp of 55 deg and ground water is the same. What temp is the water that is circulating in your floor?


So here is the big plan.
Solar panel loop closed ! circulater pump with antifreeze.
It heats the water in the large 120 gal tank. Domestic cold into large tank out to my current 50 gal superstore. What was cold in will now be preheated by solar. This will provide hot domestic and feed the heat exchanger for the radiant floor loops. When the sun is not shinning my furnace will continue to heat the superstore.

I will get into more detail as I do the install. Now to start posting some of the progress.
Phil

 

[js5020]

My house has radiant floor heat, heat source is an oil fired 50 gal Bock water heater, and I also pull domestic hot water from the system, the house is around 2500 sq ft with 6 people living in it. The house is 5 yrs old and fuel comsumption is around 650 gals per year. I thought about adding solar as a supplement last season,,,, so I did some data collecting ( very unscientific ) but none the less,, I found that most days in Dec thru Feb ( when the heat is really needed ) in my area are very cloudy with little if any sun,, I know they tell you that you just add collectors to compensate but pretty soon you get into the situation Eddie is talking about,, it takes so long to pay back is it worth it? At this point I haven't concluded whether or not it would be cost effective.

Using a water heater, be it the Bock (oil) or the Polaris (gas) I my mind is the way to go,, I have my aquastat set at 100 degrees, I do not need a tempering valve,,, never could figure out why you would heat up water only to dump cold on it ? I could run it lower than 100, but I start to hear it when people are in the showers. The heat is constant and steady,, I have wood floors and you can walk on them in your bare feet on the coldest days,,, it doesn't feel cold while waiting for the next heat cycle and when the cycle occurs your not looking to shed the sweater. I like the floor heat and would not even consider anything else.

 

[philbuilt]

Here is the study that I did to find the optimal direction for the panels.
I painted lines in the lawn by the clothes line pole. 6:30am though 6:30 pm. Them I measured out 10' feet each way and put a pin. This allowed me to pull a string and have the proper long day orientation.


The trench starting at the house.


My wife first time operating the BH


The completed trench 70' Long 4.5' deep.


Phil

 

[glmf]

Phil, thanks for the post. Please keep us posted as I live in Maine and am throwing some ideas around. I don 't mind spending money on the things I like, but spending huge money to heat my house drives me crazy. I have been getting free firewood for years but that is going to run out, and looking for alternatives,,, thanks again