Earlier, I posted about baselining my 16 x 16 garage here. Heating it has always been easier than cooling it. Not long after I bought the house, I picked up one of those single-burner, tank top propane heaters like this 15,000 BTU Mr Heater. It has worked fairly well over the years and doesn't eat up a lot of propane, but it did take an hour to get the space up to temperature. After retiring, I insulated the attic and laid down a floating PVC floor as detailed in the baseline thread. Those two items made a huge difference in being able to heat the space. It's not perfect due to gaps in the overhead door, but it's perfectly adequate. Despite the gaps, my wife insisted that I run a carbon monoxide detector in the garage, which I do and I highly recommend to others.
I live in the south and the summers here are hot (90s) and very humid. The first summer after retiring, I tried to get by with a gable fan and a dehumidifier. The overhead door opener was tapped into constant-on power, so I installed a junction box in the attic, ran power over to the gable, and installed this Quiet Cool AFG PRO-2.0 fan. After that, I ran over to Costco and picked up this Midea MAD50PS1QWT Dehumidfier. You probably already guessed that those two items didn't make a dent in the heat.
The following summer, I found a good deal on a Mitsubishi 9,000 BTU M-series Mini Split MY-GL09NA unit at Sylvane.com. This is a cool-only unit, but it only draws 8.0 Amps and that was important because my garage only has 30 Amp service. I had never worked with concrete, so the idea of pouring my own pad for the outdoor unit was a little intimidating. At first, I was considering one of those premade plastic pads, but then I saw this video on dry pouring concrete.
My dad built a form and we went through the process and the result was not bad for my first and only concrete work. We made sure to pour the pad so that the outdoor connections were reasonably lined up with where the indoor connections would come through the wall.
We mounted the outdoor unit to the pad using Tapcon screws, a few stainless steel washers, and these anti-vibration pads.
Next, we went inside and installed the indoor unit mounting template on the wall in a "reasonable" location
and test-fit the indoor unit.
Using a foot long bit, I drilled a pilot hole at a slight downward angle all the way through the wall.
That was followed by a 3-inch hole saw
starting from the inside. Once I got near the outer layer of vinyl siding, I went outside and used the pilot hole to complete the 3-inch core through the wall. I started with the hole saw in reverse to score the 20-year-old vinyl without chipping it. Once I had a good groove, I was able to put the saw in forward motion and complete the core. I discovered that the vinyl siding had been installed over wood siding with an insulating layer and that my wall was composed of 5 total layers
With the core removed, I installed this Rectorseal ProTech Rheem Wall Sleeve NFP-75 to protect it.
Home Depot sells this line cover set to protect HVAC lines and keep things looking neat. So, I purchased and installed it as well.
After that, I got a friend who was a licensed electrician to come over and do the actual wiring and plumbing for the system. Here's an outdoor photo after everything was installed. (Note: I used something like this duct putty to seal the 3-inch hole after the pipes and wires were run.)
This system not only keeps the garage cool in the summer, I run it in "fan" mode during the winter to circulate the warm air generated by the propane heater. Last year, I turned the system on in July, set the temp to 75 F, and left it running 24/7 all summer. I never noticed a bump in our electric bill and I think that's partially due to the fact that it's a 230 V system. This unit also has a dehumidifier setting, which I will probably use this winter since the Midea dehumidifier died earlier this year.
FWIW This Old House also has a on how to install a mini split unit.
I live in the south and the summers here are hot (90s) and very humid. The first summer after retiring, I tried to get by with a gable fan and a dehumidifier. The overhead door opener was tapped into constant-on power, so I installed a junction box in the attic, ran power over to the gable, and installed this Quiet Cool AFG PRO-2.0 fan. After that, I ran over to Costco and picked up this Midea MAD50PS1QWT Dehumidfier. You probably already guessed that those two items didn't make a dent in the heat.
The following summer, I found a good deal on a Mitsubishi 9,000 BTU M-series Mini Split MY-GL09NA unit at Sylvane.com. This is a cool-only unit, but it only draws 8.0 Amps and that was important because my garage only has 30 Amp service. I had never worked with concrete, so the idea of pouring my own pad for the outdoor unit was a little intimidating. At first, I was considering one of those premade plastic pads, but then I saw this video on dry pouring concrete.
We mounted the outdoor unit to the pad using Tapcon screws, a few stainless steel washers, and these anti-vibration pads.
Next, we went inside and installed the indoor unit mounting template on the wall in a "reasonable" location
and test-fit the indoor unit.
Using a foot long bit, I drilled a pilot hole at a slight downward angle all the way through the wall.
That was followed by a 3-inch hole saw
starting from the inside. Once I got near the outer layer of vinyl siding, I went outside and used the pilot hole to complete the 3-inch core through the wall. I started with the hole saw in reverse to score the 20-year-old vinyl without chipping it. Once I had a good groove, I was able to put the saw in forward motion and complete the core. I discovered that the vinyl siding had been installed over wood siding with an insulating layer and that my wall was composed of 5 total layersWith the core removed, I installed this Rectorseal ProTech Rheem Wall Sleeve NFP-75 to protect it.
Home Depot sells this line cover set to protect HVAC lines and keep things looking neat. So, I purchased and installed it as well.
After that, I got a friend who was a licensed electrician to come over and do the actual wiring and plumbing for the system. Here's an outdoor photo after everything was installed. (Note: I used something like this duct putty to seal the 3-inch hole after the pipes and wires were run.)
This system not only keeps the garage cool in the summer, I run it in "fan" mode during the winter to circulate the warm air generated by the propane heater. Last year, I turned the system on in July, set the temp to 75 F, and left it running 24/7 all summer. I never noticed a bump in our electric bill and I think that's partially due to the fact that it's a 230 V system. This unit also has a dehumidifier setting, which I will probably use this winter since the Midea dehumidifier died earlier this year.
FWIW This Old House also has a on how to install a mini split unit.
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