Looking for Shop HVAC Options

[jkohnz]

Hi all,

I have a 40x56x14 pole barn shop, with 6-8" open cell spray foam top to bottom, completely sealed. I have electricity only, no natural gas.

I'm looking for HVAC options, or at least heating, that aren't going to cost a ridiculous amount to run each month. This past summer, it never got over 82 inside, so cooling is not an absolute must. But, the coldest it got last winter was around 30-32 inside. Makes it hard to want to work on stuff! I want to keep it at a constant 60 degree temperature in the winter time. I don't know that I want to pay the expense of propane. I've been eying a 4.5 ton mini split for some time now. Any suggestions?

This is the one I'm looking at:

https://iwae.com/shop/4-to-5-ton-18...BW6_nxG7V-TMfRm8sM8ONRbrEkTTbL0BoCQYoQAvD_BwE

 

[firebirdparts]

What do you pay per kwh for electricity?

 

[jkohnz]

What do you pay per kwh for electricity?

Looks like $0.079 + peak/minimum demand charge.

 

[firebirdparts]

That’s cheap. A heat pump is going to be a lot cheaper To run than propane.

 

[theoldwizard1]

That is a BIG building ! No way you can evenly heat/cool that building for one heat source without a lot of ducting.

 

[kbs2244]

For that many sq. ft. ceiling mounted radiant would make sense
You would be heating things, not air.

 

[jkohnz]

For that many sq. ft. ceiling mounted radiant would make sense
You would be heating things, not air.

Doesn't this require propane or natural gas? Also, I have wood structure, trusses, ceiling fan, etc. Sorry, I don't know much about this. Can it be left on 24/7?

 

[karoc]

Dang, either way that can get expensive but if this is something that you make money at then maybe it kinda pay for itself. But if hobby then wow, I wonder about baseboard heat and take some fans to circulate the heat little? What warehouses use is something like this which can get for propane, hang them say in each corner then direct the louvers downward.

 

[19Vert64]

That’s a lot of space

 

[justanengineer]

Heating that volume of air, you’re going to want either multiple forced-air hanging furnaces as shown above or a single large furnace ducted to multiple locations, ~150k BTUs worth. When comparing costs you’re mostly comparing heat sources (electric, gas, oil, etc) then secondarily heat transfer methods (forced air vs radiant). Natural gas is by far the cheapest heat source stateside then they next few vary so ask around. Wood or the oft-forgotten coal is often second cheapest followed by propane or oil and finally electric. That said, my folks are on dirt cheap hydro power ($0.025/kWh) so run electric heat and it’s phenomenal and easy so again, ask around. As for heat transfer, forced air is the cheapest and evenly distributes temperature nicely with little effort. Overhead radiant setups focus temps a bit more so you tend to get hot/cold spots. In-floor radiant provides even temps but is really expensive to install & operate so I’d avoid it unless you’re wealthy.


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[jkohnz]

Heating that volume of air, you’re going to want either multiple forced-air hanging furnaces as shown above or a single large furnace ducted to multiple locations, ~150k BTUs worth. When comparing costs you’re mostly comparing heat sources (electric, gas, oil, etc) then secondarily heat transfer methods (forced air vs radiant). Natural gas is by far the cheapest heat source stateside then they next few vary so ask around. Wood or the oft-forgotten coal is often second cheapest followed by propane or oil and finally electric. That said, my folks are on dirt cheap hydro power ($0.025/kWh) so run electric heat and it’s phenomenal and easy so again, ask around. As for heat transfer, forced air is the cheapest and evenly distributes temperature nicely with little effort. Overhead radiant setups focus temps a bit more so you tend to get hot/cold spots. In-floor radiant provides even temps but is really expensive to install & operate so I’d avoid it unless you’re wealthy.

Thanks for all of that input. Not super wealthy, so tearing up an 11 month old slab to put in floor heating definitely not in the budget lol.

So, my real options are really propane, electric, wood, pellet, coal, oil. Natural gas isn't an option, as I'm out in the country a bit, not available here. My concerns with solid or liquid combustible fuel sources (wood, coal, oil, pellets) is being able to keep it running, safely, for 24/7 and unmonitored. So I guess that leaves me with propane or electric. I know they have feeder systems for pellet stoves.

I have read in the past that it's better to keep it a constant temp than to let it drop down while not out there, and then raising it up again. Burns more fuel that way? Otherwise, keeping it around 45-50 while not there, and raising it to 60 or so would be ideal.

 

[Bert_]

40x56 isn't that big of a deal to heat and cool. If you go with a furnace or air handler I would not run a bunch of ductwork. It's an open building, a trunk down one side would be fine.

I really love overhead radiant tube heaters. It feels warm as soon as you turn it on even if the building is cold. 50 - 55* is very comfortable working temperature with radiant. With radiant anything over 60 is uncomfortably warm.

 

[PWC Repair]

For starters, the one you linked to is a regular split system which requires ductwork....NOT a mini split.
If you are in mid to southern MO, with that spray foam, AND nice doors, I believe a 4 ton heat pump system will do what you want it to. I'm right at the MO and AR border and heat my 30x48x12 open span with a 4500w, 40gal, electric water heater. It was 68 in the shop today and the heat only kicked on a few times all day.
You want to save money?? Go into your local HVAC supply house and tell them you have a shop you want a heat pump put in. Can they recommend a local guy that does sidework? Or have one of them call you? Around here it seems pretty popular for a nice used "take out" system to be put into shops or rental homes. Some rich old fart remodels and installs the best high end equipment. Then the installer ends up with nice 5 year old stuff with absolutely nothing wrong with it. They resell and install it at super low prices. The guys behind the counter at the HVAC supply house will also know which contractors deal in used stuff if you want to go that route.

 

[Hobby_Man22]

40x56 isn't that big of a deal to heat and cool. If you go with a furnace or air handler I would not run a bunch of ductwork. It's an open building, a trunk down one side would be fine.

I really love overhead radiant tube heaters. It feels warm as soon as you turn it on even if the building is cold. 50 - 55* is very comfortable working temperature with radiant. With radiant anything over 60 is uncomfortably warm.

Why is it such a weird size? Why not 40x50 or 40x60?

 

[jkohnz]

Why is it such a weird size? Why not 40x50 or 40x60?

Built by the Amish. It's a multiple of 8ft "bays". The county I live in has stupid rules, so I couldn't go over the square footage of the base floor of my home. I was originally wanting 40x64, but it was too big for the county.

 

[jkohnz]

For starters, the one you linked to is a regular split system which requires ductwork....NOT a mini split.
If you are in mid to southern MO, with that spray foam, AND nice doors, I believe a 4 ton heat pump system will do what you want it to. I'm right at the MO and AR border and heat my 30x48x12 open span with a 4500w, 40gal, electric water heater. It was 68 in the shop today and the heat only kicked on a few times all day.
You want to save money?? Go into your local HVAC supply house and tell them you have a shop you want a heat pump put in. Can they recommend a local guy that does sidework? Or have one of them call you? Around here it seems pretty popular for a nice used "take out" system to be put into shops or rental homes. Some rich old fart remodels and installs the best high end equipment. Then the installer ends up with nice 5 year old stuff with absolutely nothing wrong with it. They resell and install it at super low prices. The guys behind the counter at the HVAC supply house will also know which contractors deal in used stuff if you want to go that route.

Appreciate the info. I knew that one wasn't a mini split. It's a DIY central split at a good price point. I'll have to check on the take out systems. I have the best insulated overhead door offered. This route does seem to be the best option to me. I have a friend who owns an HVAC company, who was going to have one of his guys install the linked one on the side for me for a good price. I'll check with him this weekend to see if he knows of any good used ones. Thanks!

 

[pcmeiners]

Have a Fujitsu low temp 12k in a 36x30, 10 foot ceiling, shop standard insulation. Heating and cooling the shop (and my approx 1300 sft home until I get my other heat pumps going). (2) single zone 12k low temp units as shown in the last link would easily do your shop. Two individual minisplits are more efficient than multi zone units, they would give you two sources of heat flow, and redundancy .


Below is a printscreen of my costs, with my low temp units, and other fuel costs.....
Link below that is a spreadsheet from a Maine government website. Substitute your costs for fuel in the downloaded spreadsheet.

https://www.maine.gov/energy/sites/maine.gov.energy/files/inline-files/Home-Heating-Calculator.xls

Also the Ingram unit you picked has pretty pathetic efficiency. You do not need 5 tons.

https://www.goodlifehvac.ca/images/Fujitsu_LZ_Series.pdf