Hello all, I look forward to reading to learn more,

[Jason Despaties]

When searching for a heating option for my 35*32 garage plumbed for infloor heat I have started investigating solar.

I am looking to touch base with many like minded people seems like this may be the place.

I live in Nova Scotia Canada.

I have decided to go with a glycolic system as I want to protect my floor.

System will eventually be upscale to heat my house. Two separate or togeather yet to be figured out.

System will be controlled with pumps and 12v valves useing STC-1000 temp controllers and differential controllers. So far they seem to be the most economical solution.
I thought about maybe looking for a computer control software but have done no research yet but feel this might cost a fair bit more.

So many questions but first going to read here to see if they have already been answered.

I am attaching a diagram of where I sit currently on the design.
I am reevaluating the control side of thing.

I will be using pex pipe for ease of install and to keep cost down. Building my own collector, but keeping an eye out for used ones.

[J.P.M.]

Keep the horse before the cart and start by learning how to calculate and then figuring out the design heat load for the garage. You will also find that sealing and insulation to some degree will be more cost effective than simply throwing more heat capacity at a higher load. Methods of reducing a load are almost always more initially cost effective than more energy additions.

[Jason Despaties]

The garage is in process of being insulated, walls complete, next roof. Without this I know it won't keep any heat in.

The math for figuring this all out can be very intense, I rather aim to be able to produce more heat then needed as I can easily send it to my house basement as a heat dump.

From my research so far

In space heating applications, collector surface area in square feet will typically range from 8% to 15% of the building

[J.P.M.]

The garage is in process of being insulated, walls complete, next roof. Without this I know it won't keep any heat in.

The math for figuring this all out can be very intense, I rather aim to be able to produce more heat then needed as I can easily send it to my house basement as a heat dump.

From my research so far

In space heating applications, collector surface area in square feet will typically range from 8% to 15% of the building

FWIW, I've found space heating with solar thermal design to be a little more involved than that. Lots of literature on solar thermal and space heating is available. Start with calc'ing design heat load. Have you considered passive methods for supplying solar heat ?

[Jason Despaties]

I really want to make use of the already plumbed concreat slab for heat,. When having to crawl under a vehicle be nice not to have a cold surface. Being a garage 16-18

[J.P.M.]

I really want to make use of the already plumbed concreat slab for heat,. When having to crawl under a vehicle be nice not to have a cold surface. Being a garage 16-18

Understood. Know that slab heating works best when the dwelling temp. is expected to be kept reasonably steady, that is, without any temp. setback. That means keeping the place heated when unoccupied or at night for example. I'd use a dolly. Besides, unless the slab is insulated at the perimeter for ~ 60 cm down and or underneath the perimeter to a width of ~ 1m or more , a lot of expensive solar heat will leak to the earth, particularly in Nova Scotia. Calc'ing/estimating that seasonal/yearly heat loss/hysteresis is an example of the more involved part I wrote of above.

I'm a fan of solar thermal space heating and been at it for 40+ years, but I've got to tell you, depending on inside-outside design temp. diff., insulation and sealing levels, expected interior temps. and occupancy schedule, and a bunch of other stuff, I'd be vary careful about hoping for a practical much less cost effective active solar heating solution using a slab for this application and location. I'd respectfully suggest you do a lot of self education before you buy/spend time or effort on solar equipment. You have a lot to learn or a lot to lose, maybe both. Solar can do a lot, but it cannot do everything. Insulate and seal the holy grail out of the space and heat the slab conventionally with fossil fuel. You'll need conventional means anyway for sunless periods and also most of mid winter.

Add solar air heating as an adjunct at a later date. It'll be an easy DIY project that can be done incrementally and will provide cost effective, easy to maintain equipment and useful heat without a lot of tech. education.

Do as you please, but you will not heat a concrete slab in Nova Scotia effectively (cost wise or thermally) with solar energy. More education and you'll understand why.

Good luck.

J.P.M.

[bcroe]

Listen to that advice. Until you can put numbers on the plan, nothing will work. Bruce (heating with solar) Roe

[Jason Despaties]

@J.P.M
what do you mean by "a dolly" for over night heating?

My father suggest air heating pannels on the front of the building, this is an option as well.

I ran some number from charts I got off build it solar.
after finding heat lost number for building and fidning heating degrees days for my area.

BTU needed vs BTU produced don't add up. Your experience clearly is presented here.

Also regarding the slab and insulation I know there is no insulation around perimiter of it. As for underneath it I would hope the builder of it would of installed some. Many indication that the building was super well thought out.

I installed a hoist last summer and drilled holes don't remember seeing anything indicating insulation but also was not looking.

I feel a minor setback on this at the moment

[NewBostonConst]

Heating a garage this way is not a good idea.....Trust me I did it. My last two houses are all radiantly heated concrete floors everywhere. It takes like 8 hours for them to come up to temp. Heating a garage that you are rarely in is a huge waste. Just use a electric heater when you go out there and use the power from the panels for the house.

The cost to install is cheap, and can be a selling point to some is why I did it, but have only used it a couple times. Adding a extra loop for the garage to an existing system is not that hard.

If you are going to run it 24/7 then the floor will need to be insulated. The majority of your cost will be in insulating the structure and floor.

But if you must.... o play it safe just run the tubing at no more then 1 foot spacing and keep your loops under 200 feet. In the end doing it this way you will have a foot of tubing per square foot of floor.

Then just have a thermostat turn on a pump through a relay to control it. You will then just need to do a heat loss calc to figure out the size of unit to heat the fluid going through the tubing.

Good Luck....there is much talk of this stuff on "GreenBuildingTalk".com but I think many from there are on here.

[J.P.M.]

@J.P.M
what do you mean by "a dolly" for over night heating?

My father suggest air heating pannels on the front of the building, this is an option as well.

I ran some number from charts I got off build it solar.
after finding heat lost number for building and fidning heating degrees days for my area.

BTU needed vs BTU produced don't add up. Your experience clearly is presented here.

Also regarding the slab and insulation I know there is no insulation around perimiter of it. As for underneath it I would hope the builder of it would of installed some. Many indication that the building was super well thought out.

I installed a hoist last summer and drilled holes don't remember seeing anything indicating insulation but also was not looking.

I feel a minor setback on this at the moment

I ought to have added "Instead of laying on the floor" in front of "I'd use a dolly". That is, use a dolly to lay on and move around as necessary and stay off the floor. You'll stay warmer (and cleaner).

Feel a setback if you want, but consider it a learning experience. Your lack of knowledge can and probably will get you in a lot of trouble if you proceed on the path your planning at this time. Look before you leap. Then look some more. What you don't know will hurt your wallet. Learn a bit about heat transfer and how to calculate building loads. Your ignorance of such things will cause a waste of time, money and resources.

I'd not bet on the builder doing anything in the way of insulation.

If you plan on using the in-slab heat distribution, fossil fueled or otherwise, and if you want it to be more thermally effective, to be safe, a reasonable remediation measure that will get reasonable results is to trench to a depth of at least 60 cm., or better yet, 100 cm or more around the perimeter of the slab and use 5 or more cm. thickness of rigid closed cell foam insulation, and then backfill and cover. Extend the foam above ground to match the top of slab height and cover for moisture drainage and UV protection for the insulation.

After a year or two, because heat will flow more easily into the ground from the slab than it will flow from the ground under the slab to the ground around the slab (because of the perimeter insulation), the ground under the slab will get closer to the slab temp. That will reduce or at least slow down the heat transfer from the slab, and so, lower the heating bills. It'll also increase the slab ave. year round average temp. and reduce the slab daily temp. swings.

BTW, hope you didn't drill through and of the pex when you installed the hoist.

If you're lucky, maybe after a year of two, you'll be able to get rid of the dolly and roll around on a warm(er) floor.

[NewBostonConst]

FYI, you can see the pex easily later with a thermal camera. They are only about $200 now and are extremely useful tools when building a house. I used my thermal camera to find all air leaks before drywall and ended up with a very tight house. ACH below 7. Then used it again before painting and foamed through the drywall to get all voids. Just drilled a small hole and foamed.

Good Luck with your project.

[J.P.M.]

FYI, you can see the pex easily later with a thermal camera. They are only about $200 now and are extremely useful tools when building a house. I used my thermal camera to find all air leaks before drywall and ended up with a very tight house. ACH below 7. Then used it again before painting and foamed through the drywall to get all voids. Just drilled a small hole and foamed.

Good Luck with your project.

You sure about that ACH ? seems kind of high.

It wasn't easy but I got my first retrofit to an ACH of ~ 2 unpressurized after a - 50 kpa blower door test and smoke penciling the hell out of the house. BTW, I also positively pressurized the house on a calm day and watched the fun as smoke poured from the sill plate. Learned a lot that day.

[NewBostonConst]

sorry forgot the decimal, thus meant to say under .7.... it was .67

[Jason Despaties]

@NewBoston.
I have to laugh "a garage you won't be spending must time in"
I am in the garage more then I am in the house I bought the place for the garage the house was just a bonus. So realyre I should only be heating the house when I am in it.


@J.P.M
I used a FLIR to find PEX in the slap prior to drilling. I had hope the builder had the fore thought to run PEX out for future house install. There were lots of indications there so much of this building that was done well for a garsge.

[Jason Despaties]

A photo is worth a thousand words. Here is a few of the building. It is not attached to my house. Property is 3.1 acres of land.