Occasionally Heating and Cooling attached Garage.

[Randall Edge]

Hi Guys, I'm new here. I don't even have a garage now. Mine is still under construction. We are building a new house that will have an attached 20' x 24' garage. I had not even considered AC or heat until now. Unfortunately the house is nearly finished. Has anyone used their existing house AC/furnace to heat and cool their garage? I already have a larger unit than needed to cool the house so I have the extra capacity needed and I see that you can buy electric duct dampers pretty cheap to block off the garage when not needed. Any problems with trying this aside from having to use the house thermostat and possibly introducing the aroma of heated metal into the house? This would be for those occasions when I have to get a car fixed in time for work the next morning. Those always seem to come up in December or August for me.
Thanks,
Randall

 

[Randall Edge]

Nevermind. I forgot about Carbon Monoxide. Perhaps I can add a separate unit sometime in the future.

 

[H20Man]

Oversizing your home a/c is BAD. If it's not too late, correct this before you have mold problems and high energy bills.
http://www.proctoreng.com/articles/bigger.html

 

[Randall Edge]

It is less than 1 ton over reccomended and I tend to work an AC unit hard. I like it really cool inside during the cooling season. Even though it is a little oversized it is still gonna get a workout.

 

[boiler7904]

It is less than 1 ton over reccomended and I tend to work an AC unit hard. I like it really cool inside during the cooling season. Even though it is a little oversized it is still gonna get a workout.

I've had more than one HVAC contractor tell me that he would rather see a furnace or A/C running constantly or nearly constantly than starting and stopping every few minutes. It's hard on the motors and shortens the life substantially. Haven't really seen anything to prove or disprove the idea.

 

[Randall Edge]

I've had more than one HVAC contractor tell me that he would rather see a furnace or A/C running constantly or nearly constantly than starting and stopping every few minutes. It's hard on the motors and shortens the life substantially. Haven't really seen anything to prove or disprove the idea.

I've heard the same thing. I wanted to go bigger, but the HVAC guy talked me out of it. Every house I've lived in around this part of the country has had the reccomended size unit and they all struggle to keep things cool during the summer. When I built this house I knew from the start I was gonna want an AC that didn't have to run non-stop all day long and late into the night. I even had a couple of extra supply vents and an extra return installed. I don't think it's gonna short cycle, but hopefully it won't run all day either.

 

[SteveU]

I would probably get a 12000-15000 btu window air conditioner for the summer and one of the 18000 btu free standing kerosene heaters for heat in the winter. You don't want exhaust, welding, or other fumes (think gasoline spills) getting sucked into your house & to be effective with your home unit you would have to have a return air from the garage which would do just that.

Steve

 

[MyDomain]

Mini-split inverter series heat pump would be one option

www.fujitsugeneral.com

 

[Randall Edge]

I would probably get a 12000-15000 btu window air conditioner for the summer and one of the 18000 btu free standing kerosene heaters for heat in the winter. You don't want exhaust, welding, or other fumes (think gasoline spills) getting sucked into your house & to be effective with your home unit you would have to have a return air from the garage which would do just that.

Steve

I knew I should have asked the framers to leave an opening for a window or two, but the plans didn't show one and the house is already over-budget so we stuck to the plan. The house was nearly finished before I even considered AC for the garage. If I had I would have had the outside wall insulated as well. No biggie, I'll figure something out within the next year or so.

 

[BoCRon]

We installed 3 PTAC units in our kennel building. We put them in way after the building was finished so the openings had to be cut in existing walls. A few folks here have said they don't like the fact that they have to be installed down near the floor. They don't have to be installed that low, we put the ones in our kennel about 3 feet from the floor, which according to the place we bought them from is fine. They have been keeping the building comfy with no problems. I am hoping to buy this smaller 26" unit for my garage.

Annette

http://valleyofsun.com/store.tpl?rnd=8010&cart=5A97CCC5-8EDC-40BA-AB2B-1E59102B1A70&

 

[JMURiz]

Mini-split inverter series heat pump would be one option

www.fujitsugeneral.com

I was thinking the same thing, only a small hole needed for this application as well, not a large rectangle cut.

 

[MyDomain]

And much more efficient than a PTAC unit. 18 plus seer!

 

[BoCRon]

I guess for me the difference is initial cost plus not having to find a spot for the outside portion.
I can get a 12000 BTU 26" Ptac unit that will fit in my existing window for $481.
All the mini split units I've priced start around $1000, which took those out of the running for me.
Annette