Small shop heating question

Charlie,
Our electric rates are a bit higher than yours. We went with propane as it’s used to heat the house and water, anyway. Like you, I didn’t want to trench for the lines from the main tank, so we rent a separate 50 gallon tank.
My shop heater is a 5 plaque, ProComm heater (rated for 1000 sq, ft.) in a 26X36 shop. Since our household well water pump and pressure equipment is in the shop, we heat the shop all winter. Usually the lowest setting on the heater keeps the shop at around 40 deg. except in the very coldest (‘0’) weather.
I’d say that I’m in the shop about 6-8 hrs per day, for 6-7 days a week. During that time the heater keeps the shop around 65 deg. The shop is very well insulated and that helps keep in the residual heat overnight.
The tank gets filled (from near empty to 80%) around every 6 weeks unless we get a real cold snap that lasts several days. Propane costs vary like gasoline. Since we essentially have no other cost effective options, I quit tracking the per gallon cost. We are on a cost averaging plan and our monthly is $120. That’s 11 months and for the shop, two tank rentals, and servicing all heat requirements for a 3800 sq. ft. house. As of our last billing cycle, we still had $270 overage in our account. New cycle starts 12/1.
Here in N. AZ, at 6500’ our average low between 12/1 and 3/1 is close to 20 deg. Last winter, our coldest temp was 7 deg. However, in the past, it has been -10 and it stayed that cold for 8 days.
So, to summarize, propane is our choice and, so far has been the most cost effective solution.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

3000 watts is about 10,000 BTU which would cost about $237 a month if it was on 100% and at a rate of $0.11 per KW, so you are estimating the heaters to run at 33% duty cycle?

A gallon of propane contains 91,000 BTU which would heat the shop the equivalent of 27 days at the same duty cycle as the electric proposed above.

Well, a vented propane heater will probably require twice as much gas due to flue losses but still, looks to me like propane would have to be $40 a gallon for electric to be equal.

Here in Tennessee I only pay $2.17 per gallon for propane. I heat my whole house with it because I’m miles from the nearest natural gas line.

There is a safety factor to consider though. I might go with a small electric to keep things from freezing when unoccupied, but a propane salamander or radiant type heater for when I’m working there.

-- Michael :-{| Diapers and politicians both need to be changed often; and for the same reason.

I always wanted to live up north where I could put a Franklin stove in my shop. I’m a bad enough woodworker to assure that I always have fire wood.

Takes more work, but coolness factor is off the charts.

I know your shop isn’t big enough, but it would be cool.

I will say that portable electric radiator/heaters might be just fine for an insulated shop your size. I use one on cold days in my non-insulated 2-car garage shop here in Texas.

-- jay, www.allaboutastro.com

I have a salamander type running out there now. On low it’s at the 30,000 BTU setting :)

And yes, I’m figuring about a 33% duty cycle once the equipment and concrete floor get warmed up. I’ll have to go over to our propane place and have a look at the current pricing. I think they actually install Hot Dawg heaters in small shops or garages. I guess I have more homework to do. It’ll be spring by the time I decide and then I won’t need it :) hehehe

Charlie:

My Upper Peninsula “Workshop in the Woods” is 110 yards from the house, thus “trenching” is not practical. The building is 24’x28’ with a loft, and is insulated. I selected a Resnor 35,000 BTU propane heater with the separated combustion feature, thus no exposed flame. It’s vented to the outside, where I also placed a 250 gallon propane tank. A picture of the mounted heater is on my blog.

This is a pretty efficient set-up, and as I am gone in the dead of the winter, I basically only need heat in April, a little of May, and then again in October and November. I don’t really use a heck of a lot of fuel. I like to keep everything in the shop at a constant temperature so I leave the thermostat at 69 degrees.

-- "Heaven is North of the Bridge"

I would just use electric space heaters now (the oil filled type – I think open elements and saw dust wouldn’t mix) and in the spring run a gas line from the house. I ran electric to my pole barn 200 feet from my house by renting a trencher for a day (the kind with what looks like a big chainsaw bar on the front) and backfilling by hand when the line was inspected. Wasn’t fun, but it was doable. Benefit is more BTUs over propane and you don’t have to have another account with delivery fees or tank rental fees. If you want to put heat just where you work, I’ve seen what looks like a florescent tube fixture 4 ft long with heating elements in it. Would be nice over a workbench.

High efficiency heat pump/AC unit with a programmable thermostat and be comfortable all year.

-- Clint Searl.............We deserve what we tolerate

I am more concerned with cooling living in Coastal Texas, but I do heat during late Dec – mid Feb when the temps reguarly go below freezing overnight.

It sounds like you have the first, and most imprtant thing handled, which I am working on. Insulation. Keep the heat where you want it, either in or out.

I don’t recall exactly your shop size, but I do remember it wasn’t tiny, but then again, not huge. Maybe 16×20 if I recall… I am in 18×20, and when I was fully uninsulated, unsealed doors, and VERY drafty walls (I figured out why when I opened the walls up and fixed that!), I used one 1500 watt oil filled radiator in the shop. I would put it in the shop at night, let it run until morning, on medium high. It kept the shop in the mid to upper 60s while there were 20 degree winds blowing outside, and through the gaps in my walls. (Did I mention I fixed that garbage?). My shop is 18×20…

Honestly the radiator takes too long to heat everything up. I have more or less stopped using it. I have a Mr. Heater Portable Buddy heater, 9K BTU, Low Oxygen cutoff etc… that I use now. You can use a vented heater for added safety, but I honestly feel pretty confident in the safety devices on this heater. On the sawdust issue. Just get the heater going. Once going, it is a radiant catalytic type heater, no open flame other than the start up. THEN you can produce the dust just fine…

I thought about a dedicated propane garage heater, but honestly, it’s not worth it to me… Maybe if I was in your situation, but then again, think about it this way, a portable heater you can take fishing with you…

-- Manufacturer of fine quality sawdust since 1984. Comments and advice on my shop welcome. Check it out at http://lumberjocks.com/dbhost/workshop. Gladly accepting shop build donations!

I have a two car garage shop and I’m using a Delonghi radiator heater. It’s electric but doesn’t come on much. That and a fan keeps it very cozy in there. My tools love it.

-- Failure does not stop me, it makes me try harder..... because I'm crazy.

The ProComm heater is ventless and can be purchased in 3 different sizes for your space needs. Mine is a ‘flameless’ but you still see a flame when it kicks on. Once a week I shut it down and blow the sawdust out of it. I’ve had it for 8 years and have never had a problem with it.
It’s really easy to install. It comes with both a wall hanger (like a french cleat….sorta) and feet for setting on the floor. I opted for the fan attachment and it really helps. Both the heater and the fan are thermostatically controlled. I just ran a copper gas line from the upright tank (5 ft.) to a steel pipe through the wall and then back to copper to the heater. Meets code.
The heater costs $200 and the fan was an additional $35.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

Propane today here is $2.68 a gallon. There is 91,500 BTU in a gallon of propane.
My electricity is .135 per KWHr. There is 3414 BTU in a kilowatt of electricity. That’s TOTAL including all taxes, fees, charges, and extraneous crap they tack on to the price per KWHr.

Anyways… I used an energy calculator to tell me how much 100,000 BTU would cost using propane vs electric.

It came out to $3.43 for propane and $4.16 for electric.

I might just be screwed either way. I sure can’t afford to spend $150 a month to heat the shop for 5 or 6 months of the year. Not without coming up with a way to generate and additional $150 a month from something I make or build or DO in the shop. That $150 is based on NOT needing to run a 3000 watt heating system 100% of the time. It’s about 50% of capacity. I may be able to get that number down by turning the heat down to 40 or 50 at night and when I’m not out there. Using the same kind of energy use (about 5100 BTU per hour) the propane cost would be more like $125 a month. That’s using current price per gallon only. I don’t know if I’d get charged a tank rental or other fees, but if so, then it would be around the same or more than electric.

That means I’m looking at packing up all my freezable stuff and bringing it in the house for the winter (again). And only heating the shop when I’m in it, and waiting for the tools to get warm as well as the shop ‘cause otherwise your hands just get too cold to work safely.

This isn’t real easy to figure out. You get to a point where you don’t want to do ANYTHING because it gets kinda hard to project what your actual operating costs will be.

Charlie:
I live in Northern Upper Michigan (20 miles south of Lake Superior). Shop is 24×28. It is very well insulated and sealed up. I have a Sterling (vented) ceiling mounted system, 45,000 btu. I keep the shop at 55/night & 60/day, but I can heat as warm as I want it. My house is just under 3000 s.f. I average 1400 gal/yr of propane. I run off the same tank as my house, so I don’t know exactly how much propane I use in the shop. I would guess it is about 250 to 300 gal/yr.

-- Mike - Northern Upper Michigan

well Charlie…do you have the means to crack a door or window to allow kero salamander heat? I heated an unheated space in NY for years with a 60.000BTU unit…only needed ventilation on start-up and shut-down (it stinks) but was much cheaper to operate than my replacement propane unit.

if you go salamander, keep everything away from it (like shopvac hoses). they throw off some serious heat.

related but perhaps an aside, we owned a grocery store and the freezer unit went out…our contractor decided to thaw it with a salamander…it was back in the days of poly pants…his pants went “poof” and he was standing in his shorts…funny to see but in retrospect, he could have been severely hurt (that stuff melts and will stick…3rd degree burns there).

Every now and then, I run into small marine coal/wood stoves that were designed to be bulkhead mounted. Many older cruising sailboats had them. The next time I see one (and find that it’s not ridiculously priced), I may just buy one and mount it onto the wall of my small shop. With all the insulation I have, that little fire would be all I’d need in the winter. That and a bag of blacksmith’s coal.

-- http://www.teamturpin.org/house/shop.htm