electric heaters 2 small or one large?

[T_R]

I'm putting up insulation in my shop next week and switching from my propane bullet heater to electric.

Shop is 24x24x8. I'm putting R13 in the walls and ceiling. Ceiling will just be covered in poly and the walls will have 1/8" hardboard. Not ideal I know, but it's what I can afford. Door will be getting foam panels, I think R8. I'm in Maine, winter temps are typically around 20 but can get as low as -15. My preferred temp when working in the shop is around 50-55. I'd like to keep it around 40-45 when not in there. On the really cold days I can put off working in there if the heater can't keep up, I can do other work that day in the office. I'd like the heater to be able to get it from 40 to 50 in about an hour if possible.

I'm going to buy the pro fusion electric heaters from northern tool. I can't decide if I should get 2 of these 5000 watt ones

https://www.northerntool.com/shop/tools/product_200578579_200578579

or 1 of the 7500 watt one

https://www.northerntool.com/shop/tools/product_200631888_200631888


Price difference is negligible. Which one(s) would you get?

 

[Done That]

I kinda like the redundancy, and ability to "stage" with two separate units.

 

[theoldwizard1]

2 smaller units.

 

[The FIB]

I kinda like the redundancy, and ability to "stage" with two separate units.

x2 for sure.

 

[Shop Specialties]

That small of an area I would keep it simple and go with one 7500 watt unit.

 

[larry4406]

I have a 7500 W unit in a similar size garage.

Fan throw is 10-15 feet as felt by hand.

Works well for me

With 2 smaller units you have twice the wiring to install.

 

[Falcon67]

The 5K is plenty for that space IMHO.

 

[T_R]

I have a 7500 W unit in a similar size garage.

Fan throw is 10-15 feet as felt by hand.

Works well for me

With 2 smaller units you have twice the wiring to install.

I don't mind the extra wiring. It wouldn't take long at all.

I'd like to heat it evenly. So if I put the 7500 on the one side and am working on the other, I'd be too far away from it when it kicks on to feel warm.

The 5K is plenty for that space IMHO.

One 5k is never going to cut it here. It would have to be two of them. It's only like 17,500 BTU each. My propane heater is 35,000 BTU and can barely get it warm enough to work now, without insulation I can get it into the 40's when it's single digits outside. I expect it will be better insulated, but not that much better. One 7500 might be ok.

 

[klassenl]

Insulate first, then heat. If you don't insulate your ceiling you are throwing your time and money away,

 

[ForceFed70]

He is insulating.

To the OP: I'd go with the 2x 5000W as well. The extra wattage will help you quickly bring the room up to working temp.

BUT - I strongly recommend you go higher that R13 in the ceiling. Try to do at least R20.

 

[klassenl]

He is insulating.

Yep

Saw the "just poly" part and jumped to conclusions.

 

[T_R]

He is insulating.

To the OP: I'd go with the 2x 5000W as well. The extra wattage will help you quickly bring the room up to working temp.

BUT - I strongly recommend you go higher that R13 in the ceiling. Try to do at least R20.

It's not in the budget. I got 7 bags of R13 faced batts for $150 on CL.

I'm leaning towards the 2 smaller heater now.

 

[Marctrees]

2 seperate definitely, placement depending on your expected layout, meaning where your body will spend the most time within the shop.

Marc

 

[trashmanssd]

2 small heaters on opposite walls or corners should circulate air well and leave you with less cold spots. I am in south east mass just installed a 5000-7500 watt 2 stage heater in my attached garage and it works very well. But I have R13 in walls with vapor barrier and 5/8 sheet rock and ceiling is 5/8 sheet rock with R49. Also it shares a full wall with the house and garage doors are R12.

 

[ttensirk]

I vote 2 smaller units, but I doubt you need two.

My shop is 24' x 24' x 9' with one 14'x8' insulated garage door & similar insulation. Last year I purchased an electric heater (King KBP2406 Pic-A-Watt) & installed it in the corner of my shop. From the factory it is wired for 5700-Watts, but can be wired as low as 950-Watts. It cycles on & off as needed to maintain the set temperature (40F-90F). I have my shop set at 50F & my experience with this heater has been positive. It has been positive enough for me to purchase another King KBP2406 as a backup. I'm not experiencing or anticipating any problems with my 1st heater, but I do like having a backup (just in case).

 

[T_R]

I went with the 2 5000 watt units. I ordered them from northern tool today. Insulation starts tomorrow morning. We are having a cold front move in tomorrow. Daytime highs will be single digits with night time low negative single digits for the next week. Hopefully my bullet heater can get it to at least 30 or so while I put the insulation up and await the heaters.

 

[shaggyant]

I went with the 2 5000 watt units. I ordered them from northern tool today. Insulation starts tomorrow morning. We are having a cold front move in tomorrow. Daytime highs will be single digits with night time low negative single digits for the next week. Hopefully my bullet heater can get it to at least 30 or so while I put the insulation up and await the heaters.

Two is always better than one. You’ll have a backup if one goes out.

Also, if you are trying to heat while you go and working in stages start with the ceiling. The ceiling is by far the best bang for your buck. You’ll literally feel the heat rise after each piece you install.

 

[T_R]

Two is always better than one. You’ll have a backup if one goes out.

Also, if you are trying to heat while you go and working in stages start with the ceiling. The ceiling is by far the best bang for your buck. You’ll literally feel the heat rise after each piece you install.

That's my plan. I'm going to start with the ceiling in the morning. Once I get all that up and poly over it, the heated space will be 4 feet lower. Then walls and finally rigid foam panels in the garage door. Last will be hardboard over the poly on the walls, but that will likely be next week or so, need to do some paying work first.

 

[T_R]

All my insulation is done and I installed the heaters yesterday. They work great. I tried them on 5k first but it seemed like overkill although it was kind of warm yesterday, high 20's. So I dropped them back to 3k and that seemed to work well. They run a nice cycle and shut off. I can easily get it to over 60 with both 3k. I turned them both all the way down and came out this morning and the garage was about 40 which is perfect. I like having 2 with 2 fans, it seems to spread the heat nice and even. It think it was worth the extra $40 or whatever vs. buying one 7.5k

I was a little worried because the breaker felt slightly warm when they are running, but read several places that this is normal. Later when I went back to recheck it, the breaker for our electric dryer was warmer than the heater one, so its probably normal and I never noticed it before.

 

[u3b3rg33k]

All my insulation is done and I installed the heaters yesterday. They work great. I tried them on 5k first but it seemed like overkill although it was kind of warm yesterday, high 20's. So I dropped them back to 3k and that seemed to work well. They run a nice cycle and shut off. I can easily get it to over 60 with both 3k. I turned them both all the way down and came out this morning and the garage was about 40 which is perfect. I like having 2 with 2 fans, it seems to spread the heat nice and even. It think it was worth the extra $40 or whatever vs. buying one 7.5k

I was a little worried because the breaker felt slightly warm when they are running, but read several places that this is normal. Later when I went back to recheck it, the breaker for our electric dryer was warmer than the heater one, so its probably normal and I never noticed it before.

I asked an electrician at work - breakers heating up as they near their 80% continuous rating is apparently normal and part of how they operate (remember they have magnetic and thermal trip mechanisms).

and below is my dryer breaker running: