Heating ideas for new shop

[Laurie Brown]

Hello, everyone. It's been some time since I posted on here, and a lot has happened in the interim. Our house in Virginia burned down (arson), but we had moved out before that happened luckily.
I now have a place in southeast Ohio. I was recently given an old shed to use as my new shop. The shed is 28x16 or about 500 square feet in total size, broken into two rooms. The main room which I'm currently using is 16x16, about 250 square feet.
There is foam board installed the ceiling and the wall dividing the two rooms. The other three walls are covered with built in floor to ceiling shelving and I believe are not insulated. The floor is wood with a dirt floor basement below and is also not insulated.
I have plans to eventually insulate the floor, but I don't want to demolish any of the existing shelving. Theoretically I could just install foam board in the backs of the shelving like that of the other walls.
At this point, there is no heat or AC in the building. Winter has just arrived, and our daytime highs are currently in the 30s to 40s, with nighttime temps dipping into the 20s. It doesn't usually get too much colder than that, but lows to zero or slightly below are possible.
I haven't been out to the shop since the cold hit, but it got down to 30 degrees out there overnight on a cold night and never made it past 45 even with outside temps in the 60s before dark arrived again. The back of the building which faces south gets no real sunlight because of a pole barn attached to the rear of the building with a roof. Only the back of the roof gets sunlight.
My question is, what kind of heat can I use in this space which wouldn't cost a ton to run or purchase, and isn't dangerous to use indoors? I've been looking at propane heaters, pellet stoves, wood stoves, mini-split systems, kerosene heaters, and space heaters. I have tested out an oil-filled space heater and a small fan space heater and neither one was really up to the task of heating the space more than about 10 degrees. Many heaters I looked at are for spaces much larger than mine. I estimate I only need around 9,000BTU for my space, but I could be wrong.
The advantage I saw to a mini-split is that I'd have AC as well as heat in one unit, but I'm concerned about electricity costs if I have to run it to keep the building at above freezing at night. Also, I have the option to mount a regular AC unit in the wall of the extra room eventually if I want, so AC may not be too vital.

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[Jim Becker]

Mini splits tend to sip electricity compared to options that use resistance heating elements...that was the primary reason I went that route as well as the support for AC, too. I tend to condition year round other than for those rare periods of weather that are all around pleasant around temperature and humidity.

That said, no matter what you choose, you'll benefit a lot from insulation and sealing to avoid air infiltration and well as radiated hot/cold.

[roger wiegand]

The first three things to do are air seal and insulate, air seal and insulate, and air seal and insulate. Relatively cheap, and after that heating becomes quite easy. I'd go for heat pump or minisplit these days (AC is good in southern Ohio!) Part of it depends on whether this is a full time shop or only used on weekends, for example. If you're in it every day the economics of a heat pump will quickly win, if it's only a day or two a week and you don't need to worry about things freezing then a quick heat source like gas or wood might make sense. If you've done the first three steps then the operating cost will be low with any of your choices.

[Zachary Hoyt]

My new shop is 15x31 on the inside, and heats very well with a little wood stove. I put in 4 pieces today when the high was 34 and the low last night was 18. I'll put in two more before I go to bed tonight. It stays nice and warm from just that. It has 6" of rockwool in the walls, 8" in the roof, and 2" of foam sandwiched in the floor, so it's moderately well insulated. I suppose you could blow insulation into the walls behind the shelves, but that tends to settle over time, as I understand it.

[Laurie Brown]

Ideally, once there's heat in there so I won't freeze, I would be working out in the shop several days a week if not daily. My hope is to sell what I make in the shop.

[michael dilday]

I would take a look at one of the window units that has A/C and heat pump. I purchased one several years ago for a 18x22 ft insulated shop for $800 ish. Inexpensive, efficient, easy to install and last a long time.

[Maurice Mcmurry]

I would take a look at one of the window units that has A/C and heat pump. I purchased one several years ago for a 18x22 ft insulated shop for $800 ish. Inexpensive, efficient, easy to install and last a long time.

These units can be a good solution. I have used Fredrich brand units with good results. They have some with fairly good SEER ratings. When outdoor temperatures get cold enough for the back up heat to kick in they become expensive to run. They work well along with a wood or pellet stove. Regarding small heaters with a fire of any kind, my requirements include a flue or direct vent.

[Jack Frederick]

I think your 9000 is low. As noted your first dollars should be spent to insulate the space as well as you can and reduce the load. Wood stoves are great if you have the room. I have over the years been in so many places that I look at and say “plenty of space for a wood stove.” Given the clearance to the stove and pipe, the body of the stove and the hearth clearance in that plenty of space you end up doing a doe-see-doe with the stove to get tot he other side of the room. Should youy insulate the space a mini-split is your best bet. Should you go gas I would suggest the Rinnai EX-22 for your space. I’ve used them in my homes, shops, basements and garages for 31 yrs now. They are pricey but you will not find a better gas heater. Requires a 2.5” hole in the wall for the supplied vent. Programmable state is built in, modulating gas valve and blower and a very simple install. Quiet and cool to the touch.

[Maurice Mcmurry]

I just scored an old, smallest Jotul wood stove for $500.00. It is so cute. It is ready to try out. It has snowed, I am excited, but the tiny space has become a little cramped.

[Laurie Brown]

I am thinking about insulation. I will need to insulate the floor, which currently does not have insulation, and the walls are only partially insulated. The ceiling has drywall and then someone nailed foam board over that. I will have to use foam board to insulate the walls that are covered with shelves, but I can replace the current foam board wall with fiberglass inside the studs if I want. I also could put fiberglass in the attic to better insulate the ceiling, removing the foam board to use elsewhere. What do you guys suggest? In the pics of the shop I attached you can see the current foam board on the ceiling, and on the back wall. There is basically a stud wall there and a door with foam board on only one side. The other side has nothing on it, just bare studs.

Also, I purchased a small diesel heater to try out in the shop. I've seen these used in RVs, campers, tiny homes, etc. I got one on a really good Black Friday deal, and I figure it's better than nothing and I can just try it out and see how much heat it generates. I need to get something in there at least temporarily if I want to do any work on the shop at all this winter. I took a look inside this morning, it was 32 degrees outside and 25 inside the shop.

[Jim Becker]

I would not remove the foam from the ceiling; rather, I'd put more insulation (fiberglass or cellulose) on top of the ceiling as that's a big heat loss area in any structure. The walls are trickier if you don't have access to the hollow wall. Surface mounting foam is certainly a possibility, but the material is not inexpensive (2" foam is about $50 a 4x8 sheet). You have to compare that with the effort to temporarily remove what's on the wall, do the insulation in the cavities and then rebuild the wall.

[Laurie Brown]

I would not remove the foam from the ceiling; rather, I'd put more insulation (fiberglass or cellulose) on top of the ceiling as that's a big heat loss area in any structure. The walls are trickier if you don't have access to the hollow wall. Surface mounting foam is certainly a possibility, but the material is not inexpensive (2" foam is about $50 a 4x8 sheet). You have to compare that with the effort to temporarily remove what's on the wall, do the insulation in the cavities and then rebuild the wall.

The only wall I have access to is the one between the two rooms. That one I can insulate with fiberglass. The other three walls have built in floor to ceiling shelves and no access to the walls. I do not want to start tearing apart shelving to get to the walls, so my only option is to surface mount something inside the shelf spaces.

[Jim Becker]

That being the case, it's a reasonable solution, even if not ideal from an insulation perspective.

[Ron Selzer]

Laurie try contacting local insulation contractors about having blown in insulation done. Might find out it will cost same or little more than what you will have in materials. If everybody is busy, then price will be higher.
also will have problems with high humidity come spring, summer and fall.
Once you get that area sealed up and insulated it will be easy to stay warm and cool when needed.
Good Luck
Ron

[Jim Becker]

That's a good suggestion, Ron. It can be done without ripping out the walls and is relatively easy for the contractor as long as there isn't excessive blocking in the walls.