Mini Split vs Modine Hot Dawg - SE MI

[zc15]

I am in the planning process of my garage heat source project. It is a detached 24x30. I believe there is insulation under the wall panels, and I will be installing a ceiling and insulating with blown in cellulose to get to R44 or R49. I would love to get the AC benefit of the mini split, as I have been sweating my **** off in this 95 degree heat wave.

Would a 24k btu MR Cool DIY or similar Mitsubishi 2 ton mini split suffice to keep the garage at 45 and able to bring temp up to 60 during winter in my region (SE Michigan)?

Or will it not be enough, so I should go with the 45k btu Hot Dawg I originally planned on using?

 

[jack stand]

Either way you should inspect your wall insulation situation.
The mini split gets my vote, check with your power Co. or state for any rebates. It may involve using an approved installer but imho, worth it in the long run.

 

[jlv03]

Can you do both?

 

[theoldwizard1]

Can you do both?

Why ?

True, a portable kerosene heater will bring the temp for "just above freezing" to "comfortable to work in" much faster.

 

[jlv03]

Why ?

True, a portable kerosene heater will bring the temp for "just above freezing" to "comfortable to work in" much faster.

Heat pump to maintain (plus cool in the summer), gas to quickly bring up to temp and to backup the heat pump when it is really cold.

 

[PoorUB]

The big question is what is the BTU output of the Mr Cool at the lowest expected out temperature in Michigan? some manufacturers have units that might do it, some don't As the outdoor temperature drops down so does the BTU output. You might only get 12,000 BTU at 0F wit the mini split. You need to find out the specs on the unit before you buy. Personally, i doubt it will do it in severe cold.

 

[kelpaso1]

Minisplits typically give you about a 30 degree difference in temps in the winter. IE if it is -10C out I can get +20C inside. -15C out +15C inside and -20C outside +10C inside. This is without heat strips.

 

[Jakemedic]

I opted for both, a DIY mini split and a overhead furnace. 24x32 post frame construction. R19 in the walls, single 10x8 R19 garage door, and R38 in the ceiling. I have not used the actual AC, opting instead for the dry mode, which cools and removes humidity. The natural gas furnace heated just fine in the winter. Overkill? Possibly, but natural gas is still much cheaper than electricity. Plus the mini split only heats to 5 degrees (outside temperature). Some of the other units have hyper heat which heats to below zero. They were not DIY and were much more expensive than my unit.

 

[PoorUB]

Minisplits typically give you about a 30 degree difference in temps in the winter. IE if it is -10C out I can get +20C inside. -15C out +15C inside and -20C outside +10C inside. This is without heat strips.

I wouldn't stand on that claim. I used to sell HVAC equipment. We had a mini split that would heat to -31F, but granted you got maybe 60% output at that point. So a 24,000BTU unit would get you around 14,000 BTU. So it will heat a room just fine, as long as it only needs 14,000 BTU.

Also as the temperature drops outside you need more BTU to maintain the indoor temp. A mini split is fine for heating some where above 0F, but sized for air conditioning and it will most likely be too small in severe cold and you will need auxiliary heat. You need to over size the unit so you have the capacity for heating in severe cold. Luckily the inverter mini splits will ramp up and down to meet the BTU load. So even a 36,000 BTU unit will cool a small area that might only require 12,000 BTU and still remove humidity.

Here in North Dakota I might consider a 36,000 BTU mini split for the heating BTU required. For example a Gree Vireo Ultra will produce roughly 34,000 BTU until the outdoor temp falls to 6F and the capacity falls off. At -31F it will produce roughly 20,000 BTU, which should be enough to heat a 800-900 sqft garage of typical construction and get you a 70F indoor temp. Now that same unit will ramp down to about 9,000 BTU for cooling so it will still cool and dehumidify the same garage in the summer.