Mini Split in Kalamazoo Michigan for 1600 sq ft pole barn?

[Triumph1200]

Mini Split in Kalamazoo Michigan for 1600 sq ft pole barn?

I’m concerned about operating cost and suitability for the application.

First post, lurker for a few years. I’ll try to accurately describe the build.

Natural gas is $6.50 ccf with all the charges, commercial electric rates average .15 kwh.

New construction 80 by 40 pole barn. Half un-heated storage and the other 40 x 40 will be my wife’s workplace. Her side will be fully insulated, 12 ft ceiling height, white rib steel walls, one garage door, one man door, 4 double hung windows, one large room. She can be working in it for a couple of days to 3-4 weeks and then be not using it for weeks while she is away. It will be kept at 55 degrees in the cold months when she not working in it but needs to come up to 70 within an hour, in the summer she will keep it at 85 but need to bring it down to 70 not so rapidly.

The builder is recommending a mini split and I’m thinking a Reznor unit heater and a thru the wall window ac unit which she is fine with. I’m thinking the cost to run the mini split will be high compared to the unit heater and window air, wondering how well the mini split will be able to bring the temperature up and down.

Temperatures in SW Michigan (climate zone 5) range from 15F winter nights to 90F humid summers. Extremes can go lower and higher but that doesn’t happen that often.

Let me know what you think

 

[Fordman7795]

I am in michigan also in the MBS area and just finished a 30x56 pole barn (1680 sq ft). I am going with a big maxx 80k btu NG heater and a 25k btu through the wall AC. By all estimations these should be plenty. Tight insulation and a couple ceiling fans should help do the job. So while I do not have real world working experience, I think you are on the right track.

 

[finn]

I'd go with a gas heater, but depending on what she uses the workspace for, a regular home type ducted furnace and air handler type air conditioner may be preferred. The hanging heater is cheaper, but noisy and has no provisions to filter the air, so it tends to be dirty, in my experience.

 

[tomroblee]

I'm guessing that you have your fuel costs confused in some manner. A ccf of natural gas should contain about 100,000 Btu. A kwh of electricity contains 3412 Btu (or 29.3 kwh per 100,000 Btu.) In Indianapolis I am paying more like $.70 per ccf and that rate would drop if I used more volume.

A part of the cost equation is whether you already have (sufficient) gas and electric service to supply the building with heat.

A heat pump is not likely to enable you to raise the temperature quickly. Most manufacturers seem to recommend a minimum indoor temperature well above 55 degrees

Just to control the noise and air flow I would go with a traditional furnace and ductwork. A very popular combination around here is a high efficiency gas furnace with an electric heat pump.

 

[mrpizza]

I would look at a multi split system with two high walls or two ceiling casettes. Carrier has variable speed inverter drive ones. They would give you a pretty quick temp change (for a heat pump) and be able to throttle down to maintain temps.