Need help finding solution for new garage

[lemahoney08]

Hello,

I need help finding the right solution to my heating/cooling needs.

First off, my situation. I purchased a home in southern Ohio (temps bottom out around 0 in winter and increase to near 100 in summer) with an existing detached 24x30 block wall garage. I have since then added studs and foam board insulation to the inside walls which have and r8 value. I then sheeted over that with 7/16 OSB. I have 8’ ceilings with have r19 blown in insulation. There is one walk out door and one 12’ x 7’9” insulated overhead door. I would like to find the cheapest solution to heat and possibly cool (I for sure want a good heat system, but cooling does not have to be great, just to knock the humidity out) the building, but mostly do not want to get a system and wish I had gone another route. I think I would keep the heat and A/C off until I planned on working in there, but if the heating bill was low enough I may keep it above freezing all winter. The entire house is all electric and I do not wish to add propane and natural gas is not an option. All options must be electric. My garage will be used to store some toys (Jeep, Tractor, 4 wheelers, mowers, tools, a little storage) and used as a weekend mechanic/woodworking shop. I would like to stay as cheap as possible, but plan to live there for a while, so do not want a setup that will cost a ton more in the long run. Also I plan to turn the heat on the night before or when I wake up and give it at least an hour or two before I would want to be in there. I would not be opening doors or letting heat out once I was in there. I would want it at or above 55 in the winter on the weekends when I am working out there and 85 would be plenty cool enough for me in the summer when I am out there.

Currently I am thinking about getting a decent sized unit heater. Something like the Northern Tool 220 red portable heater or maybe something a little better than that, but would like to stay under $300. I am not sure if a better option would be to get a used house furnace for heat and cooling. Anyone have any other suggestions on heating. For cooling I looked hard at the mini split systems, but could not rationalize 1000+ on A/C. I liked the idea of a PTAC but would not be able to structurally cut that much block out to fit it in the wall. Also I thought about putting a window A/C unit in, but then again I would have issues with cutting out block. I may be able to fit it in right up against the ceiling and cut out the top few blocks, but am not for sure I would want to do that. Also I had though I may be able to mount it up in the gable, because the block ends at the ceiling level and has frame trusses and siding above. If I mounted it in the gable, I would have to have some way to get the cold air out of the attic and below the ceiling. Not sure how well ducting a window A/C unit would work and having the unit above ceiling level. Not sure about any other options?

There is only one other thing I would like to know about, that would be the electrical portion. I have 150’ between the house electric breaker box and the garage. Currently I have one 40amp 220 breaker in the house that leads out to 2 15 amp 110 breakers on a farm panel on the garage. One 15 amp circuit has the outlets on it and the other has the lighting. I have plans to add a larger probably 220 air compressor and a smaller mig welder, probably 110, but maybe 220. I would like to stay away from having a separate service for the garage, so how would you go about adding the extra needed. I think if I ran one more 40amp at the house to a 30 amp in the garage for the heat/air on one circuit. But would I need a separate line for the compressor or could it also be on this line?

Thanks so much for any help.

 

[39portlander]

It will be more than your budget, but you get what you pay for. A heat pump would be ideal for cooling and some heating until it gets in the teen's then you could install a small Rinnai heater for back up. Just my .02

The new smaller 410A units are great for what your want and install is quick. For additional heating in a garage, I love the Rinnai heaters. I have this set up in mine

 

[RKA]

Kinda agree with 39portlander. When I hear "heat and cool" my mind goes to mini splits. When you have issues putting holes through walls for window units and PTACs, that gives another nod to mini splits. The mini splits can do heat well down to 30F. I'm on my first season with one and I'm finding it can maintain quite well down to 15F (lowest we've seen so far), but bringing a cold garage to comfortable temps when the outside temps are below 20F is a bit of a challenge (matter of time really). A supplemental 240v electric heater or propane tank topper could jump start the heating process, then shut off after the first hour and let the mini split do the rest.

The mini split will need it's own 240V 20amp circuit (assuming you go with an 18K btu model). You might get away with a 15K BTU, no sure what the electrical requirements on those are, but check.

A 240V 30amp heater might heat the space by itself (and it's your most economical solution right now), but it may cost you more in electric bills down the line. Only other option for AC are those portable floor standing room AC units. You said you have low expectations on the AC side, so these might work for you, but they do eat some floor space. You still need to vent those outside through a window or something. Total costs for this might be $700, but you'll pay for it in higher running costs over time. You might be able to "share" this circuit with a compressor and welder, but that might get old soon...depending on how often you're using those two.

 

[phbsales]

1 1/2 ton heat pump system with 10KW supplemental heat pack would work nicely. All electric, and the only penetrations through the block wall would be for the refrigerant lines and the electric for the condenser.

Disclaimer: The above sizing is to give you a general idea of what you will need. You should have an HVAC company come out and perform all equipment and duct sizing procedures.

 

[RPH]

Electrical supply will have to be upgraded. 40 amps is little light to run everything. Only 1 feed to the building allowed.

 

[5lima30]

I have the red Northern Tool 240v construction heater you mentioned. It heats my 16'x28' garage pretty well. Our winters are probably pretty similar to yours. The down side is the fan only has one speed and is somewhat noisy. I turn it on when I am working in the garage. I mounted mine to an old wall TV mount to keep it out of the way. BTW I have insulated since the pic was taken.