Winter is coming...Heating multiple rooms

[Slycox]

So the new shop has 2 separate rooms, both insulated and and insulated 8x7 garage door and a 2 exterior man doors and 1 going to the barn side. Currently there is two 240v heaters hanging in there. (unfortunately I do not know what they're rated at right now). Approx 755sqft total space.

My question for you folks is would I be better off to heat both rooms separately or get a larger unit and heat both?

The plus side to heating both separately is I can only have the room that needs to be heated on and the other heated side only when needed. But that is the larger of the 2 and I believe that would be using more energy than needed.

If I heated both with one unit it would depend on unit type, would it be efficient enough to put the heater in one room and leave the door going to the other open?

I could do propane but that would mean I would need to invest in propane tanks as well.

Wood is an option but I won't be out there constantly to stoke the fire.

Thanks for any advice.

 

[Done That]

Personally I would stick with the multiple units since they are in place. Basically you have zoning as you said, and can run what you need where you need it. Also, you have some redundancy with multiple units in case one should stop working.

Electric resistanc heaters are all pretty much 100% efficient, so I don't really see what you would gain by going with one large unit. 1 10KW unit is not more efficient than 2 5KW units.

Are you needing to add capacity because the two current units aren't doing the job??

 

[Slycox]

Personally I would stick with the multiple units since they are in place. Basically you have zoning as you said, and can run what you need where you need it. Also, you have some redundancy with multiple units in case one should stop working.

Electric resistanc heaters are all pretty much 100% efficient, so I don't really see what you would gain by going with one large unit. 1 10KW unit is not more efficient than 2 5KW units.

Are you needing to add capacity because the two current units aren't doing the job??

The zoning is a plus, I guess what I was wondering if using the larger unit would be able to keep both sections warm so I don't have to heat a cold room. But from what your saying it wouldn't be any different than running the 2 on a lower setting.

As far as size the one I'm pretty sure is enough for the small room at 4000 watts the other at 5000 watts might be undersized. We just bought the property and I'm pretty sure the PO had 2 heaters in that section and they took one.

Would newer units with smart controls be more efficient? I wouldn't mind updating just to get a remote for them but if thats the only reason its not worth the cost.

I am looking into a wood or waste oil burner for heat when I am out there. Fuel is free for either just costs labor. Insurance won't cover the building so no issue with them caring.

 

[yeldogt]

You are not going to save anything if you need the same watts running with one heater

Plug in your electric rate and local propane costs -- In my case with almost .20 power ... propane was a no brainer for the long haul.

Wood or oil does not negate insurance ?

 

[Jackfre]

3414 btu/kw. 92,000btu/gal of lp. figure 80% efficiency of the lp so 92k X .80=73,600 btu net to the space. I don't know what your elec rate is, but it will take 21.55 kw to equal the heat in one gal on lp.
If you go propane my suggestion is a Rinnai EX38. It has a built in stat that will allow yo to run as low as 38*. It has plenty of capacity for your space. Normally I'd suggest the EX22 for that space, but back in '77 I was a welder and worked outside for a part of a winter in Fargo. The wind blows there and it is cold wind too. After about 8 weeks one of those wind gusts blew me to the Gulf Coast for the rest of the winter

 

[matt_i]

I would run what you have to start and see what happens because you have no up-front investment. I had a 5kW heater in my small house as the only heat in middle TN and it kept it reasonably warm. In my shop 50F is just fine for most work. Not sure what temp you like to target?

In any case you will be able to get info on the running costs and see if you have enough total heat overall out there. So if you don't like either of those parameters in status quo at least you know where to go next without a lot of guesswork.

Adding, if the previous owner took a heater then I would think that you'd know it by a large double pole breaker that's abandoned or missing from the electrical panel....

 

[theoldwizard1]

Propane is very efficient, but it really depends on what it costs delivered to your door.

I would look into a mini-split heat pump. One compressor and 2 separate air handlers. Beside free A/C (which you may not care about) they are SUPER efficient, especially in the "shoulder" heating months (spring/fall). Just make sure that you purchase one that can still produce heat down to 0F.

 

[Slycox]

I forgot I had posted this, been a busy month sorry for the delay guys.

3414 btu/kw. 92,000btu/gal of lp. figure 80% efficiency of the lp so 92k X .80=73,600 btu net to the space. I don't know what your elec rate is, but it will take 21.55 kw to equal the heat in one gal on lp.
If you go propane my suggestion is a Rinnai EX38. It has a built in stat that will allow yo to run as low as 38*. It has plenty of capacity for your space. Normally I'd suggest the EX22 for that space, but back in '77 I was a welder and worked outside for a part of a winter in Fargo. The wind blows there and it is cold wind too. After about 8 weeks one of those wind gusts blew me to the Gulf Coast for the rest of the winter

Thanks for the tips and the info on the elec to propane heat. We're paying ¢10 a KW.
I'm about 75 north of Fargo, nothing like -10° with a 20MPH wind. Why do I live here?

I would run what you have to start and see what happens because you have no up-front investment. I had a 5kW heater in my small house as the only heat in middle TN and it kept it reasonably warm. In my shop 50F is just fine for most work. Not sure what temp you like to target?

In any case you will be able to get info on the running costs and see if you have enough total heat overall out there. So if you don't like either of those parameters in status quo at least you know where to go next without a lot of guesswork.

Adding, if the previous owner took a heater then I would think that you'd know it by a large double pole breaker that's abandoned or missing from the electrical panel....

That's the conclusion I came to was run them and see what it is costing etc, I'm not looking for alot of heat just enough to keep the water lines from freezing when I'm not out there and then enough to keep my nuts from freezing when I am.

And the reason I assume they took a heater is there is a 240v plug abou 2ft from the ceiling right next to a couple largeish holes. I doubt it was a welder.

Propane is very efficient, but it really depends on what it costs delivered to your door.

I would look into a mini-split heat pump. One compressor and 2 separate air handlers. Beside free A/C (which you may not care about) they are SUPER efficient, especially in the "shoulder" heating months (spring/fall). Just make sure that you purchase one that can still produce heat down to 0F.

I really would love a mini split, but the problem is its more than I can budget for the shop and they don't work so well in the frozen tundra we have up here.

Any way I am planning on using the electric as the heat when the its empty, and I just picked up a waste oil burner today that hopefully will clean up well.