I’m building a 40x60 with 12’ sidewalls with an open ceiling. I’m trying to figure out what way I want to go. I’m in southern Missouri. We may be living in the shop this winter and spring. I figure I’ll be using the heat more so than a/c so I’m curious if I should go a propane heating route or just go with a mini split. A buddy recommended a 3ton unit with one head that he said would do it just fine with the 3” of open cell insulation. What are your guys opinions and setups for a shop this size?
Heating and cooling a shop
- Thread starter Flinging
- Start date
karoc
Well-known member
For a DIY project I don't think you can beat mini split, but for a full time unit you can't beat split system like what is in your house. Service trucks will have parts for the house hold systems and life span is 20 plus yrs. I replace my system last yr which it was around 35 yrs old.
ericm
Well-known member
You can use load-calc.net to determine how much heating and cooling you'll need.
Gas vs electric (mini split) will depend on your local energy prices and cost to get each of those to your building. Keep in mind that a mini split being a heat pump produces 2-8x heating or cooling than the power it uses (i.e. 20,000watts of heat might take only 5000watts of power). Unfortunately the most efficient heating is at high outside temps, and the most efficient cooling is at low outside temps, opposite of what you want. Of course with gas heat you will still need electric A/C.
Also if you'll be living in there at times you'll probably want more heat and cooling capacity than if it's only going to be a shop.
A single mini split air handler is going to have a hard time conditioning all of a 40x60 room, even with fans. Mr Cool DIY mini splits have multiple air handler models now.
Gas vs electric (mini split) will depend on your local energy prices and cost to get each of those to your building. Keep in mind that a mini split being a heat pump produces 2-8x heating or cooling than the power it uses (i.e. 20,000watts of heat might take only 5000watts of power). Unfortunately the most efficient heating is at high outside temps, and the most efficient cooling is at low outside temps, opposite of what you want. Of course with gas heat you will still need electric A/C.
Also if you'll be living in there at times you'll probably want more heat and cooling capacity than if it's only going to be a shop.
A single mini split air handler is going to have a hard time conditioning all of a 40x60 room, even with fans. Mr Cool DIY mini splits have multiple air handler models now.
ambenz
Well-known member
Well if money is "NO OPTION" ...all the guys will give you their idea of the best way to go but you'll end up spending $1 to 10K on installation.
We all love spending other peoples money!
I do not have a answer to your query, too many variables to actually know for sure.
I myself like the "options" method and you have to ask, how can I do it on the cheap with minimal cost to install and maintain.
Don't want to decide now and money is no option?
Put in a chimney thru the roof so you will have that option.
Run a 3/4" gas line from the meter to the garage so you will have that option.
Run a 100 amp breaker box to the garage so you will have that option.
Run radiant tube in the slab so you will have that option.
Decide later or based on the best option now and later in the future.
Mini split might be fine now but electric prices might have you kicking yourself in the future you did go the natural gas route for heat and a window AC unit for cool.
You may find a bargain on pellets and end up running a pellet stove, running a swamp cooler using money for more insulation.
No one has the right answer but you will find the more options you will have available, the better you will be prepared to go to the least expensive/biggest bang for your buck, now and in the future.
We all love spending other peoples money!
I do not have a answer to your query, too many variables to actually know for sure.
I myself like the "options" method and you have to ask, how can I do it on the cheap with minimal cost to install and maintain.
Don't want to decide now and money is no option?
Put in a chimney thru the roof so you will have that option.
Run a 3/4" gas line from the meter to the garage so you will have that option.
Run a 100 amp breaker box to the garage so you will have that option.
Run radiant tube in the slab so you will have that option.
Decide later or based on the best option now and later in the future.
Mini split might be fine now but electric prices might have you kicking yourself in the future you did go the natural gas route for heat and a window AC unit for cool.
You may find a bargain on pellets and end up running a pellet stove, running a swamp cooler using money for more insulation.
No one has the right answer but you will find the more options you will have available, the better you will be prepared to go to the least expensive/biggest bang for your buck, now and in the future.
finn
Well-known member
I think Karol has a point. Mini splits seem to have a lot of proprietary components, and a lot of plastic, so one should probably consider them disposable after some time frame, depending on use.
They also have limited filtration, which bothers me for shop use, although many are ok with them.
I like the Mitsubishi units in my house, though.
If you go with mini splits, look at a couple of individual units rather than one unit with multiple heads. Cost and performance was better with multiple units last I checked.
My preference would be a conventional system if air was a must, and hanging heaters if I was looking for the cheapest solution.
For your location, in floor hydronic would never pay off.
They also have limited filtration, which bothers me for shop use, although many are ok with them.
I like the Mitsubishi units in my house, though.
If you go with mini splits, look at a couple of individual units rather than one unit with multiple heads. Cost and performance was better with multiple units last I checked.
My preference would be a conventional system if air was a must, and hanging heaters if I was looking for the cheapest solution.
For your location, in floor hydronic would never pay off.
I have a 60x40x12 in Raleigh, NC. stick built, slab, insulated head to toe with spray foam.
I installed a 3.5T heat pump that can bring it to 70* within 2 hours when I am working there.
I only run the heat pump when I am out there...otherwise it is 55* to 85* when not in use.
I installed a 3.5T heat pump that can bring it to 70* within 2 hours when I am working there.
I only run the heat pump when I am out there...otherwise it is 55* to 85* when not in use.
My car house is 40x40x14 and the in law apartment is 24x40x8.Heat/ac is provided thru a single unit with a head in each.It does a great job warming and cooling.I think the key is insulation though.I have only had to use the ac in my shop a few times this summer.
STINEY
Well-known member
This is similar to our building. What size is the unit? I am guessing a 3ton 36,000btu with twin 18,000 head air handlers? What brand and model?
I am really close to pulling the trigger on one of these and would greatly appreciate your info.
Thanks.
greenskeeper
Well-known member
recycled forced air oil furnace (free) supplemented with a recycled wall mounted A/C unit (also free) acting as the HVAC in my 1100 sq ft detached
theoldwizard1
Well-known member
You must have EXCELLENT insulation ! Hard to heat/cool a 24x40x8 with one air handler.
theoldwizard1
Well-known member
I do NOT agree with your buddy ! One air handler is not going to distribute the are in that big space. I would go with two 2ton units and 4 air handler.
Open cell foam holds moisture. Closed cell does not. If this is post and beam construction with metal walls, I hope you had house wrap installed before the metal !