Need propane heater ideas for insulated 42x60 Morton bldg

[Code54]

A propane forced air heater sounds like it might work for my 42x60 and 14 ft high building. Can you tell me more about this one? Any idea what it costs?

The first thing you want to do is get a load calculation (you could try to get a rough idea by doing one online). That will give you a decent idea of what you need for your shop at your location. This varies a lot due to location, insulation, # of windows, the direction the structure sits, etc. Here is a simple version:

HVAC Load Calculator

An easy-to-use HVAC tool for calculating necessary thermal output capacity (in BTUs) This tool is based on the square foot method, with computations added for the most important values included, such as insulation, windows, and other contributing factors. The system is pre-set to a 72-degree...

www.highseer.com

A forced air unit is not too bad money-wise, 200btu for around $1500. They just hang from the ceiling on uni-strut and you need a gas line run to it and an exhaust. That's really it, nothing to doing the installation. You can also run two units in your shop and place them on the same or separate thermostats depending on the layout if you feel it is needed.

Your ceiling height will be a bit of an issue so you may want to consider a few fans to bring the warm air back down to where you are working. Also if you have open rafters a ceiling would help keep the warm air where you want it.

 

[LouNY]

At times a load calculation mostly a waste of time a large shop IF it's going to have the doors opened several times a day in the colder weather it will need a unit much larger then the calculated values as those are mainly for a building being uniformly heated at a constant temperature.
A shop that will empty much of the heated air in the 10 minutes a door is open to move a vehicle or piece of equipment in or out needs much more capacity to reheat the mass air change.
If it is a shop that will not have the large doors opened often or has an airlock type entrance can use the calculations as it is a much more consistent load.
I have seen some decent shop heaters put together using a couple of older mobile home furnaces set in the back corners with individual thermostats.

On smaller shops that are not evenly warmed and are heated to be workable the salamander heaters on thermostatic switches work quite well.

 

[dodge man]

This is what I have in mine, they come in different sizes, they need a small vent, about like a water heater had, run on 110 volts and usually sit up high in the corner.

 

[sixdogs]

This is what I have in mine, they come in different sizes, they need a small vent, about like a water heater had, run on 110 volts and usually sit up high in the corner.
View attachment 941135

How big is your building and how tall inside? Could one heat a 42 x 60, 14 ft high building to 50 degrees or so? What BTU do you think required?

 

[dodge man]

Yes it would. In my post earlier I said a ceiling fan or two would help. I had mine installed by an HVAC place and they sized it, 60,000 btu’s. It’s oversized for my 28’x30’ shop but I think he said it was only $20 more for this one. I keep mine between 40 and 45 degrees in the winter and it warms it up to 60 degrees in less than 15 minutes.

The good thing about one of those corner units, probably the cheapest option. I’m not sure how big of one you’d need. One like mine cost about $500 now, you might need one that cost around $1000.

 

[Code54]

We run 120btu in a 30'x40' 10' high (16' at peak) and can keep the shop at 70 in pretty much any weather we get. Again, a LOT depends on insulation, wind, windows, seals, etc...

Also, I know you mentioned keeping it at a lower temp but depending what you do you may want it warmer. We restored another old Farmall last year and if it was not 70 I would not have been able to paint and finish the machine throughout the winter. Something to think about....

 

[gstrom99]

I had my (1300 sg ft) shop walls spray foamed. 2" closed cell. Sealed the (leaky) metal siding perfectly from any wind. Ceiling 12" blown in. Price was about $4200 for each process, but worth it. 100k btu Hot Dawg was $3500 installed.

 

[stucknutz]

I have a 36x48x14 tall pole barn and i actually have a Reznor forced air heater and also a radiant tube heater. They perform very different and can consume a lot of energy depending on circumstances. My personal choice is the Radiant heat. There is no substitute IMO. Only downfall I feel with the Radiant tube heater is you need to maintain a certain temp in order to use less energy. (I know sounds backwards) It will suck a lot of propane if you are trying to heat a cold shop with it. I mostly turn mine on in early October when the concrete and all the steel in the shop is still warm and i maintain it throughout the year.

Forced air in a cold shop and the top half of you will be warm and the bottom half will be freezing along with your tools and everything else. It takes a very long time for a forced air heater to heat a shop evenly.

I attached a pic with both of them in the shop.

 

[grsthegreat]

Well, i heat up my 30x40 mostly uninsulated shop in about 20 minutes…. Warm enough to lose jacket. I could care less if my tools are warm. The heater is off all other times unless im working in there

 

[gstrom99]

Here's my Hot Dawg, up in the corner.