Can I do solar radiant heat in Wisconsin?

[rombi]

I do not know much about solar so I thought I would ask some people who know a lot more that I.

I live in WI (green bay) and I have a dog kennel that is about 1000 sqft. I heated it and our house with wood for the last 6 years and I am about done with that. The roof faces the south.

The building does have in floor heat that the wood boiler was to run but it comsumes too much wood to keep it going so I hung a HX with fan and that does a fine job keeping it warm.

My thoughts are that I have this in floor tubing with all the pumps and the slab is well insulated under and on the sides and if I could let a solar system heat the water and pump it into the slab all days that are clear that it would help a great deal as the boiler could focus on heating the house instead of both.

It might not work at all and that would be fine I can use propane if I need to but I think the wood for the kennel is going to be shut down this year.

 

[GaryGary]

Hi,
There are people in your kind of climate that successfully heat with solar -- there are some examples of the systems they use here on this page:
http://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm
Have a look in the Active Water section, and in particular the first half dozen in that section -- they mostly use radiant floor heating with solar.

Of those first few systems, Mine is in Montana, Tom is in upper Michigan, Ken's folding collector one is in Wisconsin, Steve is in Maine -- and so on -- mostly cold climates.

So, you can certainly do it. How effective it is depends a lot on how well insulated and sealed your place is, and how much collector area you can manage.
Even if the place is well insulated and sealed and you can manage (say) a couple hundred or more sqft of collector, don't expect that solar is going to provide all your heat -- you will definitely need backup heat for some periods -- the solar will help lower your fuel bill, but not replace conventional heating. Its possible to do a 100% solar heated home if you are starting with a clean slate, but nearly impossible for a retrofit.

Gary

 

[semipro]

The December/January issue of Homepower magazine had an article on this subject with a title starting with "hydronic heat...".
https://homepower.com/issue-gallery

 

[midwestcoast]

Is that kennel insulated as well as a house would be? Have you gone over it thoroughly for air leaks?

 

[rombi]

no it is not. it is an insulated block building and there are some leaks due to the dog doors and cheap windows. it might not work, just thunking if i had access to free collectors if it was worth the time.

 

[Circus]

200 sq ft of solar hot air mounted on the south facing wall ( not the roof) should cut your heating bill in half. They are simply shallow glazed boxes, with something dark inside, that have lower and upper air ducts through the wall. The rising heated air siphons on it own in through the upper duct. Flaps prevent reverse thermal siphoning at night or when cloudy.
In Wisconsin the really cold Canadian air is dry and sunny. The warm gulf air is moist and cloudy. So when you need solar the most, it works the best. Fond du Lac

 

[GaryGary]

200 sq ft of solar hot air mounted on the south facing wall ( not the roof) should cut your heating bill in half. They are simply shallow glazed boxes, with something dark inside, that have lower and upper air ducts through the wall. The rising heated air siphons on it own in through the upper duct. Flaps prevent reverse thermal siphoning at night or when cloudy.
In Wisconsin the really cold Canadian air is dry and sunny. The warm gulf air is moist and cloudy. So when you need solar the most, it works the best. Fond du Lac

Hi,

I think that the thermosyphon design that uses screen or lath as a flow through absorber is a good deal more efficient than an empty black box. Steve Baer of Zomeworks did quite a bit of work on this many years ago and came up with a set of design rules -- I tried to follow them in this collector: http://www.builditsolar.com/Projects/SpaceHeating/solar_barn_project.htm
it works like a champ.

The testing that Scott and I did last year also indicated that the screen absorber collector is produces about 50% more heat per sqft in side by side tests with an empty box collector: http://www.builditsolar.com/Experimental/AirColTesting/Index.htm

But, in the end, a lot depends on the insulation and sealing of the kennel -- doing heat loss calc would give a better idea what the gain might be.

Gary

 

[midwestcoast]

Well, if you can get free collectors and the radiant is already installed I say why not? It will certainly help, and a warm floor would be good for dogs even if the air temp is cooler in there.
I'd bet that the best bang for the buck/time will be in air sealing though.
Check out some diy interior storm windows on Gary's site above. if your windows are single pane these can cut the heat loss through them in half.
I also have seen double flap pet doors with magnetic closures to be much more air-tight.
Caulk & foam everything else you can.

 

[Circus]

Solar Hot Air observations after 5 years with 100 sq. ft of solar hot air heating my 1400 sq. ft home. Heats very well when the suns out. At night the heat loss is very small with dampers on both ducts or just on the lower duct. It desperately needs some sort of buffer to even out the 90F days and the 50F nights. You could use a ceiling fan to warm your concrete slab. I don't have an insulated slab so I've been saving 2 liter bottle full of water. Hundreds of them.
The thermal mass idea is thousands of years old. Germans use to fired up their massive hearths only once a day.

 

[4acrefarm]

I use polyester felt as an absorber, and I use solar powered computer fans on one and 120v squirrel cage on the other they work very well.

 

[Circus]

My solar hot air collector has sheet steel painted black hung between the glazing and back side. Holes by the ducts allow the rising air to cool both the front and back side of the sheet metal.
The one most important feature of a solar collector is not to lose heat when idle.
Rombi, I've seen twin walled polycarbonate greenhouse glazing for sale at Menards. My polycarbonate (not from Menards) is five years old and shows no signs of deterioration and zero maintenance.
Here's a photo of my small garage collector.