3 car garage electric heater

[jlash630]

I am looking for opinions on on what kW size 240v heater I should get for my garage now that I'm moving to electric brewing. I'm in northern Illinois and cold garage brewing sucks! Thankfully I won't be needing to keep the door open to prevent death any longer.. I'm going to use a steam condenser, so the heater doesn't need to compete with a hood/make up air..

I have a 3 car garage that is fully insulated and drywalled, I'm not really trying to hear it to a comfy 72.. 60 is more than adequate, and most of the time, it will just be to keep SWMBO car warm (you know... Happy wife...)

I've seen a couple pictures online that say 10kW for a 3 car.. is that necessary? I mean, that's another 40A circuit. Granted i have a 200A main.. but would a 7.5kW or 5kW be enough?

 

[Scout]

Id say it depends of how well insulated and sealed it is. Is it an attached or detached garage?

 

[day_trippr]

The thermal mass of a three bay garage will take time to move much on a cold day from a standing start. I think I'd go with localized overhead infrared for the brew space vs just some random space heaters trying to bring the whole space up to temperature inside of a brew. I know when I step inside the contractor entrance at a Home Depot or Lowes and get under the IR heaters the sensation of warmth is immediate...

Cheers!

 

[matt_m]

I have an attached 3 car fairly well insulated garage (walls and ceiling) with insulated doors in southern MI. I have a 30K BTU wall mounted gas heater. If I'm working out there and turn on the heat it will pretty quickly take the chill out of the air but the floor, cars, tool chest, etc are still cold. After about a while the humidity from the non vented heater, any moisture from the cars, breath, etc will start to condense on cold surfaces. Usually the garage doors first which I guess it the best option. Never seems to affect my tool chest which is good. After 24 hours the floor and other large objects have warmed sufficiently that its no longer a problem.

For brewing, I think you are going to have more of an issue even with a steam condenser. I brew in my finished basement with a steam condenser. I still in the summer notice I have to empty the dehumidifier after a day instead of every 3-4 days. I'm still putting a decent amount of water into the air from various brewing activities. Nothing like before the condenser, even with a hood and its not enough to worry about in the winter since its pretty dry anyway.

If you keep it around 40-45 full time or at least several days before brewing you may have far better luck controlling humidity. I used to do that in a very well insulated detached shop building full of woodworking tools. Unheated I'd get condensation on cast iron. When I kept it 40-45 I could kick it up to 60-65 to work and it would jump quick with no humidity.

 

[Scout]

I have an attached 3 car fairly well insulated garage (walls and ceiling) with insulated doors in southern MI. I have a 30K BTU wall mounted gas heater. If I'm working out there and turn on the heat it will pretty quickly take the chill out of the air but the floor, cars, tool chest, etc are still cold. After about a while the humidity from the non vented heater, any moisture from the cars, breath, etc will start to condense on cold surfaces. Usually the garage doors first which I guess it the best option. Never seems to affect my tool chest which is good. After 24 hours the floor and other large objects have warmed sufficiently that its no longer a problem.

For brewing, I think you are going to have more of an issue with a steam condenser. I brew in my finished basement with a steam condenser. I still in the summer I notice I have to empty the dehumidifier after a day instead of every 3-4 days. I'm still putting a decent amount of water into the air from various brewing activities. Nothing like before the condenser, even with a hood and its not enough to worry about in the winter since its pretty dry anyway.

If you keep it around 40-45 full time or at least several days before brewing you may have far better luck controlling humidity. I used to do that in a very well insulated detached shop building full of woodworking tools. Unheated I'd get condensation on cast iron. When I kept it 40-45 I could kick it up to 60-65 to work and it would jump quick with no humidity.

A friend of mine had a large shop with one of those ventless natural gas heaters and he never turned it off, never noticed rust on anything, and with what he was doing he had a lot of bare steel in his shop. I dont know what it cost to run the thing, but I know his shop was sealed and insulated pretty well.

 

[matt_m]

Yeah, I think its more about keeping temps above the dewpoint than controlling humidity. As soon as the air temp goes over surface temps, its "sweat city." To be clear, my old shop had a vented furnace.