garage climate control questions

Hello,

I went through the same contemplations about twenty years ago with our 1,000 sqft car park. We’re in the Hottttttston, Texas area so we’re well familiar with the temperature swings in Texas.

Our 3-bay car park is well insulated in the walls (combo batt and expanding foam), but only high tech radiant barrier in the ceiling joist area. I started out with a window unit that could not keep up with the Texas summers and the heat load from cooling two SClass V-8 Benzes with hot engines.

We added another whole house size window unit that helped, but it still did not *really* work well. Winter heating was not easy either, using radiant oil heaters. I finally got tired of the constant faff of trying to heat and cool the car park and we installed a dedicated central HVAC unit several years ago.

This works a treat and it was much less in monthly cost than using the two window units and the radiant oil heaters. So, we keep our car park 74/75 degrees in the summer and 68 to 70 degrees in the winter (natural gas heating).

Easy peasy and the HVAC unit easily handles the heat load from the outside temps and the two car engines. If you need more info, just let me know. Cheers bruddah!

 

I keep my garage at 60 in the winter and 78 in the summer. Well worth it!

 

My garage AC is set to 69 degrees for summer with about $100/mo. hit. Worth it to expel the humidity.

 

My car park HVAC has a thirteen speed fan (IIRC) and is capable of a sub function for specific humidity % control. This works a treat! The unit can run on a really low fan speed for humidity control with little cost due to the step down fan controller. In Hooootston, it’s not the heat but the humidity that gets ya.

 

My new garage building is 36' x 84' with 14' walls. I am going to try to get away with two 5 ton mini splits. I am in FL, so mostly a/c, only need heat 5 nights per year or so.

 

You ‘da man bruddah!!! Wow, down in Hooootston, we would call a car park that size a “hanger. “ Applauding claps, woo hoo’s, cheers and attaboy’s...

I would love it if my car park ceiling was even 10’ high, but alas it’s only 8’ high, so no four post lifts for this retired wannabe F-mechanic bloke... Cheers!

 

Oddly enough, I had an auto repair shop for 10 years. The shop had 10' ceilings. I couldn't lift most vehicles high enough to stand under them being 6' tall. I got a nice reclining office chair and soon discovered that I preferred to sit down while I worked under a car, easier on the feet than that concrete floor! My new building is 14' walls and 12' x 12' garage doors so I can get a motorhome in there if desired.

 

If you have an HOA, make sure they allow window units if you go that route. I have a 5 ton HVAC on my 40' x 60', but it is a metal building and not as sealed as a regular garage might be. A window unit might struggle in the summer in the panhandle.

 

This is an excellent example of thinking “outside of the box”, great job!

 

I recently put up my new 'Garden Shed' at 50' x 96' . R24 in the walls and R40 in the ceiling. Walls are 12' 6" and the ceiling is flat. Concrete slab floor 5" thick. I run a dehumidifier in it year round and keep the humidity around 45 to 50 percent. I do have a propane fire tube heater but keep it around 40 to 45 degrees Fahrenheit during the winter. Nothing is rusting and the cars with wood body framing seem to be happy as well.
I would run a dehumidifier over the 'window shaker' just punch a hole in an outside wall for the drain.
We get temperature fluctuations from -10f in winter to 95f for parts of the summer.


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Good advice.

I did pretty much the same after a lot of investigation, the only things I can add:
- a wooden garage is best to store cars, as it ‘breathes’.
- I keep humidity between 50 and 55% (below 50 is not ideal, neither is above 60 %).
- Avoid sudden big temperature fluctuations as they cause trouble.
- I keep temperature above 12 degrees Celsius (about 54 Fahrenheit) and below 25 degrees (about 77 Fahrenheit).
- The best tip above: very good insulation (don’t skimp on that): as it keeps heat and cold out of the garage... what you want to achieve is a favourable stable climate. If possible: it’s easy to diy your wall insulation: you’ll be proud afterwards. If you’d consider that: I’m more than happy to provide you some tips and tricks.

 

Keep temp range 50-70F and humidity at 50%

 

Have in floor radiant heat in the garage floor. Keep it at 51F in the winter. That is the perfect temperature to store wine. Just white wine overflow in the winter.

71F in summer. If l want to spend time in the garage it is comfortable.

 

Radiant heat is the way to go if new construction, but also need AC for summers near me. I put in a small HVAC unit for my garage and keep the temps similar to PhilNotHill's recommendations. I use outside air source for the gas burner in the winter so I don't blow up the garage from the fumes coming from my Austin Healey.

 

Our house has central air and the developer who built it included the garage. A nice touch indeed.

 

Is your garage on a fully separate zone ? Around here you cannot return garage exhaust to a central unit that services living space. Not sure you would want to either. Great if its in its own zone and the best way to go.

 

When designing mine the first thing was to totally waterproof the brick walls inside the garage. 2 system . Epoxy twin pac first as that stops ALL water ingress and egress. Then 2 coats water based waterproofing compound.
Then I built an internal timber frame 12 inches of the walls. I basically stuffed 4 layers of 4.5 rating insulation in the walls and roof. Then I lined the whole garage with 9 mm cement sheeting. Doing this greatly controls the delta of the room.
Solid concrete ground with 20 granite tiles.
NO GARAGE doors as they do not seal. Rather glass sliding doors. The mission i wanted was a sealed room.
A small HVAC system that has the air double filtered controls the Temp perfectly as there isn't much variation. About $!0 / month
I have another filter and filtered exit so the air gets flushed away for 1 hr every day at about 1.00 pm

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BTW, mine is a detached garage.

 

There is no air return in the garage. There is no thermostat in the garage. The thermostat is inside the house. 71F. If the doors have been left open during the day it takes a while for the garage to cool. High daily temps are in the low 80s this time of year.

The in floor radiant heat has a thermostat in the garage. It works well. At 51F in winter it does not take long for the engine to get to normal operating temperature.

 

sounds like you have the HVAC solved but can I suggest you buy a rubber/vinyl floor mat for the garage they sell 9 X 16 or so thin mats that are designed to go under the car that will prevent any most from coming through the concrete ...
they are also nice looking .. best of luck

 

Mine is not fancy or glamorous, and my garage is the bottom floor of an odd stilt house on a low-lying island neighborhood in Florida. I had the concrete floor sealed with a polyurea epoxy product as there was some odd moisture intrusion, and we had a Mitsubishi Mr. Slim mini-split unit with humidity control installed. We have no widows for a window unit. Walls are cinder block and not insulated or sealed other than paint on the exterior. The AC unit keeps it at 76 degrees with 50% humidity easily. Been a huge benefit as a lot of rubbers, foam pieces, and plastics have degraded just sitting in a hot humid garage over the years. Electric bill never increased as I guess it benefits from having two floors of air conditioned house above it. One of the best things I ever did for all my things I keep in the garage.