Heat/AC Help in MN Garage

[mnwebb]

Hello Gurus,

I need your thoughts on heating and cooling the garage in the attached plans. I hope to begin building in about a month.

Backstory - As you can see it's a garage with a small studio 2nd floor. The 2nd floor space will be used much more than the garage space will. My plan is that the whole structure gets super well insulated, and the 2nd story space also gets it's own insulation.

I don't have gas out there, but could run it out. We are in MN so heat is important. Do I make it two circuit in-floor heat or is that a waste of $? Electric baseboard and mini-splits...IDK.

What would you suggest?

Thanks,
Wilson

 

[theoldwizard1]

"You pay for insulation once, you pay for heating/cooling every time the thermostat calls for it !"

Minimum 2" of rigid foam plus a vapor barrier below the slab regardless of what type of heating you choose. 12" of loose fiberglass or cellulose blown in insulation in the ceiling. 2x6 construction with 6" fiberglass roll will also help.

Natural gas is always the cheapest heat source, but then you have to pay extra for A/C. If you don't have natural gas available and A/C is important, I strongly recommend you investigate a mini-split.

 

[mnwebb]

theoldwizard thanks! Think fiberglass on the walls, above the foam, is better than loose cellulose?
The concrete guy isn't a fan of insulation under the slab but I am!

 

[theoldwizard1]

theoldwizard thanks! Think fiberglass on the walls, above the foam, is better than loose cellulose?

Spray foam is expensive. Put a ceiling in and use blown in fiberglass or cellulose. Much cheaper.

Do you have gas ? How important is A/C ?

 

[4 FN 27]

What would you suggest?

Let's roll with this...

"You pay for insulation once, you pay for heating/cooling every time the thermostat calls for it !"

No disrespect to the Wiz but here is what I would do and have done...keep in mind we share almost the same Zip Code.

I'll start at the bottom and work my way up.

ICF (Insulated Concrete Forms) Foundation: Less Heat loss.

2 Inches of Foam Under the Concrete Radiant Heat using a NG Boiler: If you have a MN Contractor who is not a fan of insulating Concrete in a heated Garage you have the wrong contractor. No offense, just my opinion. Radiant Heat will be your best friend to help evaporate the snow and ice brought in by your vehicles. With the Salt residue left behind you want that humidity level as low as possible to prolong the life of your vehicles.

Trench Drain: To aid in getting the Water/Moisture out of the Garage. This is an absolute must if you are heating. As mentioned in another thread spec 3/32 to 1/8 per foot pitch. That is all you will need. A marginal Concrete guy will insist on 1/4-1/2 per foot because they are not skilled enough to work it the right way. Get a good Concrete guy.

Spray Foam the entire Garage: The main idea is to seal the Garage tight. You will be compensating for the seals (or lack there of) on the Garage Doors. Insulating properties are secondary but important. Spray the Walls and spray the Ceiling of the Garage too. This will help reduce the amount of heat trying to make it's way upstairs in the summer. Spray the Ceiling above the "Bonus Room" and blow in Insulation above that too.

Remember Insulation is to minimize Heat Loss. This hold true for both the Winter and the SUMMER. In the winter a heat soaked vehicle help warm the Garage. But that same heat soaked Vehicle in the Summer will turn your Garage into an Oven. I would suggest functioning Windows on both levels. I wish I had done this on my garage. I have windows but they do not open. One more lesson learned. I leave the Garage Doors open until I go to bed to let the heat out. Living in the Country I have locked many creatures in my Garage for an over night stay. You being in St Paul Proper...not sure if you want the "nocturnal creatures" in your Garage.

Heating the Bonus Room: Using the same NG Boiler, use a Heat Coil and forced Air. 2 separate Zones, Upper and Lower.

AC: Again, 2 separate zones, Upper and Lower, Central AC System ducted.

I am not too far from you. If you would like to see an example send me a PM and we can set something up so you can see why and how.

 

[mnwebb]

4 FN 27 Thanks for your opinions!