Game Changer Heat & A/C In the Shop

[JCM 10,619]

Back in 2009 I installed a Modine 45,000 BTU Hot Dawg LP heater in the garage. Only time it got used was in the  Fall / Winter when a tractor needed to come in for whatever to be out of the elements. In 2024 I bought another one for the shop, a 30,000 sealed combustion type , same brand with a Summer switch as well. Finally this past fall I installed it. When I was working full time I just didn't have the time to do it but always wanted a heated shop like I had at my last residence. I have been out there for the past month sorting, rearranging and throwing things out, etc,etc. I also added another workbench, just need to paint it in the Spring. I built the bench so I could get a WH under it on one end and made a brace back to the 6x6 PT post. Really enjoying my time spent out there and finding parts everywhere. Trying to label everything and find a home for it. Been on average 20 degrees out there upon entrance and climbing to 60 degrees within 35 minutes. Shop is 12' x 22. Searching on McMaster Carr for rubber mat for the floor. That opened up a can of worms, a LOT to choose from. Probably do that in the Fall. Also, on the back wall I framed an opening and installed a Friedrich 8000 BTU A/C unit.Still a bit to go but nice to get organized again.

[Sparky-(Admin) 24,526]

Yep! 
  I’m jealous!
  I need to get serious and finish insulating my garage and then put in a better heating unit.

[squonk 45,343]

My garage is 12' X 24' and I heat it with a 24,000 BTU Empire Direct Vent Propane wall heater. R11 insulation in the ceiling and walls. It's 3° with the chill at -15°. I put the t stat on the lowest setting last night and it was 40° in there this afternoon when I needed to go out and get something. I only run the heat when I'm out there or like now when they predicted 6" of snow or more and I wanted the loader oil warmed up just in case.

 

There was a window in the back wall to a smaller uninsulated shop but I took that out years ago and installed an 18,000 BTU Carrier window shaker running R22 that I got from my brother's printing shop. I only run that if it's a zillion ° outside.

[Achto 30,772]

Walked in the ole corn crib this morning and it was 7f. Wood stove & the kerosene torpedo heater got er up to 70f in about 3hrs. All this so I can get some painting done.

[JoeM 9,546]

I heat mine to 50 and keep it there, I so no difference in the electric bill vs going cold to warm. 

Do a couple weld jobs in a month and the cost of heating the shop is insignificant. 

It is nice to walk in and everything is not cold as ice and I can jump right in. 

[Beap52 1,951]

I keep my shop about 50 degrees.  I've got paint, flowers that we are keeping alive and I'm out there pretty much every day and other stuff I don't want to freeze.  I have a propane wall hung ventless heater with a fan above to circulate the air.  It works great until a board is sawn or a spray from aerosol  can in which case the door are opened for fresh air.  Not only does it stink, I  can bring tear to a fellow's  eyes.  I try to do all spraying outside.  Then a couple years ago I installed a ceiling hung electric heater.  I made a holder so I could install  furnace filter behind and therefore capture sawdust before it goes through the heater.  This works very well.  

 

I keep the propane heater at about 50 and kick on the electric when I want additional heat. 

[ebinmaine 77,044]

3 hours ago, JCM said:

rubber mat for the floor

 

 

Workshop space is looking great Jim! 

 

For those floor mats we went to TSC and got horse stall mats. 

Very reasonable prices but they're not as soft and fluffy as a standard expensive people floor mat.  

 

Horse mats will likely outlive the building though...

 

[JCM 10,619]

Those ventless heaters are dangerous. Not recommended. Hopefully you have a carbon monoxide detector as I do in the shop. BE SAFE PLEASE .   @Beap52 That second piece of vent pipe brings in fresh air from outdoors on the shop heater. 

[Bill D 2,582]

I'm a big fan of electric shop heaters.  I have a 4000 watt heater in my 2 car garage.  Does a great job.  Made in the USA, no glowing coils, and the fan motor is a refrigerator fan motor made for constant use.  Very safe heater.

Edited yesterday at 12:33 AM by Bill D

[JCM 10,619]

My CMP = Central Maine Power bill has gone somewhat ridiculous , NOT happy. Also in the Plumbing & Heating / GasfittingTrade for 50 years.  @Bill D

[Sparky-(Admin) 24,526]

  I have this beast hanging on my 28’ x 36’ garage. But without the insulation complete it works hard. I yanked it out of the storage room of a package store around 25 years ago. Messed with it and unwired a couple of the heat elements to get the total draw down to around 23 amps so that I could run it on a 30a 2 pole breaker in my house, its been pumping out heat ever since. The fan motor is 208v but not 3 phase so that’s how it works in my house. 
 

 

 

[wallfish 19,036]

3 hours ago, Beap52 said:

I keep my shop about 50 degrees.  I've got paint, flowers that we are keeping alive and I'm out there pretty much every day and other stuff I don't want to freeze.  I have a propane wall hung ventless heater with a fan above to circulate the air.  It works great until a board is sawn or a spray from aerosol  can in which case the door are opened for fresh air.  Not only does it stink, I  can bring tear to a fellow's  eyes.  I try to do all spraying outside.  Then a couple years ago I installed a ceiling hung electric heater.  I made a holder so I could install  furnace filter behind and therefore capture sawdust before it goes through the heater.  This works very well.  

 

I keep the propane heater at about 50 and kick on the electric when I want additional heat. 

Propane adds humidity too and a lot. From the net "For every pound pf propane burned about 1.5 - 1.8 pounds of water vapor is generated."  I don't understand that math but I do know it can be a hassle. 

I had some issues with heating my shed with only ventless but then I added an RV heater which is vented. Use the ventless heater to heat it up quickly because the vented system is definitely slower getting there but then maintain the heat with vented unit. When running the ventless heater continuously things would end up dripping with water. Something to consider. 

[ML3 2,121]

My garage is 24x24. Walls are OSB then insulated w/Rockwool (expensive but worth it)  Ceiling is foam insulation board with 2' of blown on top of that. Insulated overhead door too. I have 2 1500w electric heaters. I keep 1 set @40° all the time & it will maintain the temp. The 1 heater will get garage warm until about when it drops into the teens outside. Thats when I need both. Even with as cold as its been for weeks here it takes about 1-2hrs for both heaters to get garage in the mid 60s to almost 70°. I dont worry much about cost to operate them. We have a small, efficient house & just 2 of us living here so none of my utilities are expensive. I been looking into installing a mini split heat pump unit then I'd have a/c as well. 

[ebinmaine 77,044]

10 hours ago, JCM said:

My CMP = Central Maine Power bill has gone somewhat ridiculous , NOT happy. Also in the Plumbing & Heating / GasfittingTrade for 50 years.  @Bill D

 

Yep. Electric bill is nuts compared to years ago... but what isn't. 

 

We went with electric heat because of the mountainside boulder infested land making it extremely prohibitive for the logistics of installing propane. 

 

Electric heat has been perfect for us though. 

Easy. Clean. Quiet with the right heater. 

 

The game changer for us though is the wood stoves. We have the advantage of living in the same forest we harvest and very much enjoying the work of getting the firewood. 

[Bill D 2,582]

10 hours ago, Sparky said:

  I have this beast hanging on my 28’ x 36’ garage. But without the insulation complete it works hard. I yanked it out of the storage room of a package store around 25 years ago. Messed with it and unwired a couple of the heat elements to get the total draw down to around 23 amps so that I could run it on a 30a 2 pole breaker in my house, its been pumping out heat ever since. The fan motor is 208v but not 3 phase so that’s how it works in my house. 
 

 

 

I stopped at a neighbors yard sale years ago and picked up something similar for free.  I was stunned when they said it was free.  Nothing wrong with it other than needing a good cleaning and straightening one air deflector fin.  Even had a 24  volt thermostat hook up.  A little too big for my needs at 7500 watts, so I  sold it to a friend from work.  Still in use to this day.

Edited yesterday at 12:08 PM by Bill D

[pfrederi 19,760]

The workroom in the shop building is the 14x22.  Well insulated except for the door and windows.  6' oil filled electric base board keeps it a 50 degrees .  I have a 220v heater that I turn on when I am working gets to 65-68 quickly.  Have an A/c for summertime.   The rest of the building where the horses live was 13 when I went out a while ago.

 

[SylvanLakeWH 30,441]

I'm uninsulated, 1500 w heater does pretty much nothing other than take the edge off... but, it is nice in the fall / spring...

 

 

[oliver2-44 11,196]

My shop is 18 x 26 and well insulated. R19 walls, R19 ceiling and the room above is also all R19

A 1500 watt electric heater keeps it 60F+ down to 30F. 

I almost turned the window AC on this afternoon!

[WHX?? 54,436]

On 2/7/2026 at 1:01 PM, JCM said:

Modine 45,000 BTU Hot Dawg LP heater

I never cared for the Hot Dawgs Plunger. They had a Honeywell fuzzy logic intermittent pilot ignition that was somewhat troublesome. Pilot orifice would plug easy. Prolly all together different now tho. 

[JCM 10,619]

Have had good luck with the one in the garage so went with another one, no issues. Installed them for customers as well, no issues. @WHX??

[WHX?? 54,436]

1 hour ago, JCM said:

good luck with the one in the garage

Good deal ... I never sold them (Modines) but service calls on plenty but like I said they probably come along ways since those days. 

 

I have & sold ones made by Advanced Distributor Products which is a Lennox company so they were branded both ways. 

 

Venting was usually done through the roof with B vent as if you went side wall you were supposed to use stainless ventin due to condensate issues. That upped the price considerably. Never used sealed combustion like what you have unless it was industrial or commercial environment.

When I retired a install like yours would have been way north of 3k. I had a program where you could get one for free if you spent $$$ with me on a RNC.

Tom @Shynon put one in his shop for way less than 1k in his shop. 

 

My problem was you could buy them at big boxes for less that what I could through my wholesalers and I had a brick & mortar to support and keep open.  

 

I do like that plenum they exhaust/draw from you have. Guessing a Modine option? Had to take some careful measuring to get lined up with the heater for strait out like that.  

 

No offence guys but folks that did any type of electric heating were thought to be on crack be it in a shop, garage or residence. It was a quick easy and affordable install but just too outrageous power bills in these parts.

 

[WHX?? 54,436]

Another game changer when these came out. I used them in the later part of my career. Quite a bit cheaper back then. 

https://www.supplyhouse.com/DiversiTech-QSWI3000-Quick-Sling-Unit-Heater-Swivel-Mount?utm_source=google_ad&utm_medium=Shopping_Plumbing&utm_campaign=Shopping_X_Plumbing_X_SSC_Hybrid&utm_campaignid=22376844123&utm_adgroupid=176639540106&utm_targetid=pla-2439502424577&utm_product_id=QSWI3000&utm_matchtype=&utm_keyword=&utm_adtype=pla&utm_category=Plumbing&gad_source=1&gad_campaignid=22376844123&gbraid=0AAAAAD_WAyuxvl9IwXdhW9kT1fOShW_2B&gclid=CjwKCAiAqKbMBhBmEiwAZ3UboKiQNCzfCgx4I7USlQlJPy7mi9WtAhq5WUIo_qglg1piyxVFEzY_uBoCoFAQAvD_BwE

 

 

[JCM 10,619]

Never seen those swivels @WHX??  Different

[Blue Chips 642]

On 2/7/2026 at 2:01 PM, JCM said:

Back in 2009 I installed a Modine 45,000 BTU Hot Dawg LP heater in the garage.

 

I'm looking at getting something similar in the way of a ceiling-mount, direct-vent, sealed-combustion unit to replace the existing electric heater, which puts a big dent in my wallet.

 

On 2/7/2026 at 3:00 PM, squonk said:

My garage is 12' X 24' and I heat it with a 24,000 BTU Empire Direct Vent Propane wall heater.

 

I was considering something like that, but I think I'm going to go with a ceiling-mount unit, as I really don't have the available wall space for a wall-mount heater.

 

On 2/7/2026 at 4:22 PM, JoeM said:

I heat mine to 50 and keep it there, I so no difference in the electric bill vs going cold to warm. 

 

I keep my workshop (former 2-car garage) at least 50 degrees all the time and warm it up a little when I'm working in it. I've found that if I let it get too cold and then warm it up, it can create condensation on my equipment, primarily during the cooler parts of the spring and autumn when the interior air is more humid. It's not so much a problem in the winter, as the winter air in the shop tends to be very low relative humidity. I have a dehumidifier in the shop, but it virtually never comes on in the winter.

 

On 2/7/2026 at 7:32 PM, Bill D said:

I'm a big fan of electric shop heaters.  I have a 4000 watt heater in my 2 car garage.  Does a great job.

 

The current electric heater in my shop is a 5,000 watt unit (a little over 17K BTU), and it can keep the shop (about 575 square feet) warm when the temps drop below zero, but the power bill  !

 

 

On 2/7/2026 at 8:22 PM, JCM said:

My CMP = Central Maine Power bill has gone somewhat ridiculous , NOT happy.

 

We're on CMP as well, and I'd probably use an unprintable expletive to describe the power bill, a good portion of which is attributable to my electric workshop heater. My workshop is in our old two-car garage, which is pretty well insulated...walls, ceiling, and garage doors...and the current 5,000-watt heater keeps it nice and cozy, but it doesn't feel quite as comfortable when I remind myself that my power bill is helping to subsidize Spain's economy...not that I have anything against Spain, but gee whiz.

 

Edited 4 hours ago by Blue Chips

[WHX?? 54,436]

6 minutes ago, JCM said:

Never seen those swivels @WHX??  Different

Oh yeah a complete game changer. They came out about five years before I retired ... 2016 + or -. 

I boycotted them at first as I thought they were  too $$. About 100 wholesale but competition was fierce back then. Vendor gave me one to try and I was hooked. One guy could dang near hang by himself. 

Universal fit to any brand and for 16 or 24 OC rafters. Best thing you mounted it square then swivel for that custom angle.