bsimon Posted December 22, 2008 Share Posted December 22, 2008 Anyone here an HVAC tech? I'm adding a Modine unit heater to my 3 car garage. It's 860 sq. ft. with 9 foot ceilings, insulated. Average low temp in our area is 14F. We get maybe a dozen below zeros in a bad year. One local HVAC guy says 45000 BTU should be fine to get the room to a nice working temp in cold weather, however a 60000 BTU unit would recover faster when the missus opens the door to drive the Oldsmobuick to the grocery. I understand that bigger is not always better as the furnace will cycle more often and wear out faster. Any thoughts? Link to comment Share on other sites More sharing options...
jbanker Posted December 22, 2008 Share Posted December 22, 2008 Bob, I am heater approx 720 square feet of garage space with 9 ft ceilings that opens into another 575 square feet of garage space through a 4 ft wide door that is 8 ft tall. There is no door to close between the two garages, however, I have an 8 mil plastic sheet that I can drop between the two if I don't want to heat the 575 ft side. I can heat the 720 square foot workshop/garage area with a 5000W electric heater at a very comfortable 62 degrees in about 20 minutes. The 5000W is equivalent to about 17000 BTU. If the Modine heater is vented to the outside then you will have inefficiencies of about 20-30%. He is correct, it will do an excellent job but I have found that working in the garage with temps much over 65 degrees is almost too much. My garage is well insulated with 10" batting in the attic. Do you know if the heater is vented from the outside. If not you may want to back off to about 30000 BTU which is still plenty for that size unless the garage is not well insulated. Hope this helps. Jack Over 30 years of Industrial Process Heat experience (not HVAC. We heat things...not people) Link to comment Share on other sites More sharing options...
bsimon Posted December 22, 2008 Author Share Posted December 22, 2008 Jack, Thanks for the tips. The Modine is vented to the outside, but combustion air is from the heated space. I had one of those Daton/Farenheat 5KW heaters in my last garage. Since the garage was uninsulated, it took 30-40 hours to bring it up to 50f so I could get a little work done. The numbers on the leccy meter were a blur as they speed by. :ack: Added $150 to the monthly bill. Industrial heating, eh. I just spent a couple of days last week replacing the elements in my Lindberg HT furnace. Wrong controller parameters allowed a runaway. The TC loop-open thingy had been disabled somehow. :cry: Link to comment Share on other sites More sharing options...
Davemk1 Posted December 22, 2008 Share Posted December 22, 2008 I work out of my garage and it gets plenty cold here and I heat with a wood pellet stove. I can heat all day everyday during very cold weather and use two bags of pellets. A bag of pellets cost about $4 here. It' makes nice radiant heat and is very quiet. I need to talk on the phone a good bit from the garage and a gas forced air heater would just be too loud to have a business call. I don't regret my purchase at all. Dave Link to comment Share on other sites More sharing options...
drew... Posted December 22, 2008 Share Posted December 22, 2008 Bob - I heat a ~950 sq ft garage (3 exterior walls) with a 45000 Modine unit here in wonderful Minnesota (-16 without windchill this morning). Recovery to 45 degrees after opening a double garage door can't be much more than 5 minutes. I can time it if you would like. Link to comment Share on other sites More sharing options...
bsimon Posted December 23, 2008 Author Share Posted December 23, 2008 Thanks Drew, I could live with a 5 or even a 10 minute warmup, and we don't have nearly the heat load of MN. I have a feeling that HVAC contractors err on the plus side for peace of mind...and a possibly piece of ones wallet. I'm thinking 45000 BTU would probably be adequate 'round these parts.:thumbs: Link to comment Share on other sites More sharing options...
Carz01 Posted December 14 Share Posted December 14 I realize this is an old topic. I’m looking to install an electric, ceiling mounted garage heater, about 5K KW for a 600 +/- sf garage. I’m curious if people installed explosion proof units in their garages, or standard units. Any thoughts from the community are appreciated! Link to comment Share on other sites More sharing options...
JohnCh Posted December 14 Share Posted December 14 My shop is 1260 sq.ft with ceilings just shy of 9-1/2 ft. No complaints with my ceiling mounted Fahrenheat 5000W heater (FUH54C). It's rated for a much smaller space, but it still has no trouble getting the interior to comfortable working temps (~60F) in freezing weather. Link to comment Share on other sites More sharing options...
Carz01 Posted December 15 Share Posted December 15 Thanks @JohnCh, I appreciate your feedback. Looks like a standard heater will do the job. The unit you have isn’t available any longer but I’ve found others that are similar. Link to comment Share on other sites More sharing options...
Marek Posted Tuesday at 04:58 AM Share Posted Tuesday at 04:58 AM (edited) A friend just installed minisplit heat pumps in his new 1700ft^2 garage. Very effective and efficient! https://mrcool.com/diy-4th-generation Edited Tuesday at 05:10 AM by Marek Link to comment Share on other sites More sharing options...
Carz01 Posted Tuesday at 02:14 PM Share Posted Tuesday at 02:14 PM Hey @Marek thanks for that information. I had contemplated doing that, but based on my garage size it was larger than needed. I’ll probably go with a small electrIc heater to keep it workable in winter. How’s your Rotus going? Link to comment Share on other sites More sharing options...
wdb Posted Tuesday at 06:35 PM Share Posted Tuesday at 06:35 PM I have a mini-split in our 800 sq.ft. insulated garage. Makes heat in winter, cool in summer. Uses next to no electricity; when the guy was installing it he told us we might not even notice it on the electric bill, and sure enough he was right. Link to comment Share on other sites More sharing options...
slowdude Posted Thursday at 04:00 AM Share Posted Thursday at 04:00 AM Cheapy oil office heater from a yardsale in the neighboring wealthy town for $10. Keeps the edge off the cold in the garage to work with a jacket on. Not great but a cheaper solution to colder weather. Link to comment Share on other sites More sharing options...
Carz01 Posted Thursday at 11:17 PM Share Posted Thursday at 11:17 PM Hey @slowdude thanks for that. I’m assuming the heater is 1500w, I’ll have to try that and see how it works. I know it’s undersized, but hey, anything would help. Link to comment Share on other sites More sharing options...
Marek Posted yesterday at 01:47 AM Share Posted yesterday at 01:47 AM On 12/17/2024 at 9:14 AM, Carz01 said: Hey @Marek thanks for that information. I had contemplated doing that, but based on my garage size it was larger than needed. I’ll probably go with a small electrIc heater to keep it workable in winter. How’s your Rotus going? @Carz01 The first part of the season was great as we had it out once a week or more. I had planned to refresh the wiring harness this winter as it came to me with some damage from running higher current lights than the wiring could support. But my luck ran out and the harness began failing; so the winter project began in August. A few higher priority projects later (like learning how to program a Alfa TCT dual dry clutch gearbox), and the Rotus is still in the garage. But January is looking quiet and the car should be ready with fresh wiring and a fix for the trammeling well before the salt clears in spring. Thanks for asking...encouragement is always good. Link to comment Share on other sites More sharing options...
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