PNWTim
03-10-2025, 11:32 AM
The Background
I thought it might be helpful to share my experience with a mini split install which I did about 3 weeks ago. This won't be so much of an install thread as just a review of my personal experience. For a little background, I live in Oregon, outside of Portland about 20 miles east. I retired in January of 2024 and realized I spend more time in my garage than I do in my house during the day. Portland can get relatively cold in the winter with streaks of weather in the 20's and 30's.
I built my shop about 15 years ago. It's 1800 sq ft with scissor truss ceilings (12' at peak) and is stick built. I put the maximum amount of insulation in it that was available. I think the batts in my ceiling are almost 2' thick. There is a wall that divides the build in half so each portion is 900 sq. ft. I have a 5000 watt Dayton heater in each half which I have used for heat. When truly cold outside (December/January) it would take about 2 hours to get comfortable inside. I am not a polar bear so like my working temperature to be around 68F.
Fast forward to a month ago. We had a long streak of cold weather, I received my electric bill for Dec/Jan and it was $200 higher than I expected. PGE has given us significant rate increases and although our hydroelectric power is still less than other areas, that delta stung a bit. I embarked on a research project and decided to install a mini split. I was originally going to install a 2 head unit but then realized it was more costly than installing two separate units so I decided to beta test the garage and if it panned out, install another in the woodshop. Based on extensive research (much of which was a bit overwhelming), I chose a Pioneer Inverter+ in the 18K size. This unit is appropriate up to 1000 sq/ft.
https://www.pioneerminisplit.com/collections/wys/products/18-000-btu-ductless-dc-inverter-mini-split-air-conditioner-heat-pump-230-vac?variant=14703002222634
The Install
The unit arrived in two boxes containing the compressor and the head unit. Both were packed well and in good condition upon arrival. I had determined where I wanted the head unit and did a quick layout and installation of the mounting plate. These units are meant to be installed eight to nine feet above the floor. I had watched many, many YouTube's on this topic and in one I caught a useful tip which had me drill the through holes slightly lower than shown on the template. This turned out to be excellent advice. This portion installed easily. I had to do a bit of electrical work which included installing a 4 slot subpanel on the wall close to where the original heater circuit wiring was. I used this circuit to power the mini split and ran additional conduit and shut off box outside for the second unit.
Because the head unit was relatively close to the compressor I went ahead and cut and flared the refrigerant lines so I wouldn't have an extra coil to deal with. This was a little nerve wracking but I did a lot of flares on my last car project so I felt I could do it. I mounted the compressor unit on a wall stand about 4' up so it was at a comfortable working height. I connected everything up and installed a cover for the lines to clean it up a bit. All of this work was very straight forward and just basic carpentry and electrical work.
The Charge and Test
This is where things got interesting. One of the reasons I decided to attempt this project is because I had almost everything needed to complete it (manifold gauges, vacuum pump, etc.). Once installed, you do need to vacuum the lines, then do a quick purge, test for leaks and release the refrigerant (they come with a can of refrigerant inside the compressor unit) to fill the lines. Well, to put it succinctly, mine would not hold vacuum. The problem with this scenario is it's telling you you have a leak but not how to find the leak. Leaking air into a vacuum is not the same as leaking pressure to atmosphere i.e. it's hard to find. So I stewed around for a few days, did way too much research and finally landed on the idea I needed to pressurize the system so I could find the leak (this is what installers do). Went down to Airgas and rented a 40 ft cylinder of nitrogen. Bought a gauge set off Amazon, hooked up the bottle and gosh, what do you know? The system held 200 psi of nitrogen for 4 hours. Now it's a real head-scratcher. Logically, the system is sealed if the nitrogen isn't going anywhere. Ergo, if it's sealed it should hold vacuum. Ensue another 2 days of stewing around knowing I knew just enough to know I didn't know anything.
I called my buddy who I remembered was a HVAC guy at one time. We walked through the entire scenario and what does he say? "Your manifold gauge set from Harbor Freight is leaking". Never dawned on me to question the tool I was using. Bought a Yellow Jacket gauge set (can use it on the Coupe when the time comes), pulled vacuum (it held for 4 hours), purged the air for a second or two, released the refrigerant, and have enjoyed a warm, dry 68F shop ever since.
Summary
Am I going to install the second unit in my woodshop? Absolutely! Was it a bit of a pain in the *** and cause severe mental anguish for a week or so - yes. But, I write that experience off to bad luck. Had I not had a faulty manifold gauge set it would've been a piece of cake. I think I can probably install the second unit in 2 days, start to finish. For those of you wondering about the cost, here is a quick breakdown:
Pioneer Unit - $1050
Ancillary Parts (line cover, wall bracket, etc.) $125
Electrical supplies (wire, subpanel, shut off box, wire and whip) $150
Other crap I had to buy and rent which I am not counting was about $200
Based on wattage usage my projected monthly cost to run this is somewhere in the neighborhood of $50/month in winter. So, all in, I think the ROI on this investment is probably going to be fulfilled by December of this year as I am looking forward to some air-conditioned summer days in the shop as well. I hope you find this write-up helpful.
I thought it might be helpful to share my experience with a mini split install which I did about 3 weeks ago. This won't be so much of an install thread as just a review of my personal experience. For a little background, I live in Oregon, outside of Portland about 20 miles east. I retired in January of 2024 and realized I spend more time in my garage than I do in my house during the day. Portland can get relatively cold in the winter with streaks of weather in the 20's and 30's.
I built my shop about 15 years ago. It's 1800 sq ft with scissor truss ceilings (12' at peak) and is stick built. I put the maximum amount of insulation in it that was available. I think the batts in my ceiling are almost 2' thick. There is a wall that divides the build in half so each portion is 900 sq. ft. I have a 5000 watt Dayton heater in each half which I have used for heat. When truly cold outside (December/January) it would take about 2 hours to get comfortable inside. I am not a polar bear so like my working temperature to be around 68F.
Fast forward to a month ago. We had a long streak of cold weather, I received my electric bill for Dec/Jan and it was $200 higher than I expected. PGE has given us significant rate increases and although our hydroelectric power is still less than other areas, that delta stung a bit. I embarked on a research project and decided to install a mini split. I was originally going to install a 2 head unit but then realized it was more costly than installing two separate units so I decided to beta test the garage and if it panned out, install another in the woodshop. Based on extensive research (much of which was a bit overwhelming), I chose a Pioneer Inverter+ in the 18K size. This unit is appropriate up to 1000 sq/ft.
https://www.pioneerminisplit.com/collections/wys/products/18-000-btu-ductless-dc-inverter-mini-split-air-conditioner-heat-pump-230-vac?variant=14703002222634
The Install
The unit arrived in two boxes containing the compressor and the head unit. Both were packed well and in good condition upon arrival. I had determined where I wanted the head unit and did a quick layout and installation of the mounting plate. These units are meant to be installed eight to nine feet above the floor. I had watched many, many YouTube's on this topic and in one I caught a useful tip which had me drill the through holes slightly lower than shown on the template. This turned out to be excellent advice. This portion installed easily. I had to do a bit of electrical work which included installing a 4 slot subpanel on the wall close to where the original heater circuit wiring was. I used this circuit to power the mini split and ran additional conduit and shut off box outside for the second unit.
Because the head unit was relatively close to the compressor I went ahead and cut and flared the refrigerant lines so I wouldn't have an extra coil to deal with. This was a little nerve wracking but I did a lot of flares on my last car project so I felt I could do it. I mounted the compressor unit on a wall stand about 4' up so it was at a comfortable working height. I connected everything up and installed a cover for the lines to clean it up a bit. All of this work was very straight forward and just basic carpentry and electrical work.
The Charge and Test
This is where things got interesting. One of the reasons I decided to attempt this project is because I had almost everything needed to complete it (manifold gauges, vacuum pump, etc.). Once installed, you do need to vacuum the lines, then do a quick purge, test for leaks and release the refrigerant (they come with a can of refrigerant inside the compressor unit) to fill the lines. Well, to put it succinctly, mine would not hold vacuum. The problem with this scenario is it's telling you you have a leak but not how to find the leak. Leaking air into a vacuum is not the same as leaking pressure to atmosphere i.e. it's hard to find. So I stewed around for a few days, did way too much research and finally landed on the idea I needed to pressurize the system so I could find the leak (this is what installers do). Went down to Airgas and rented a 40 ft cylinder of nitrogen. Bought a gauge set off Amazon, hooked up the bottle and gosh, what do you know? The system held 200 psi of nitrogen for 4 hours. Now it's a real head-scratcher. Logically, the system is sealed if the nitrogen isn't going anywhere. Ergo, if it's sealed it should hold vacuum. Ensue another 2 days of stewing around knowing I knew just enough to know I didn't know anything.
I called my buddy who I remembered was a HVAC guy at one time. We walked through the entire scenario and what does he say? "Your manifold gauge set from Harbor Freight is leaking". Never dawned on me to question the tool I was using. Bought a Yellow Jacket gauge set (can use it on the Coupe when the time comes), pulled vacuum (it held for 4 hours), purged the air for a second or two, released the refrigerant, and have enjoyed a warm, dry 68F shop ever since.
Summary
Am I going to install the second unit in my woodshop? Absolutely! Was it a bit of a pain in the *** and cause severe mental anguish for a week or so - yes. But, I write that experience off to bad luck. Had I not had a faulty manifold gauge set it would've been a piece of cake. I think I can probably install the second unit in 2 days, start to finish. For those of you wondering about the cost, here is a quick breakdown:
Pioneer Unit - $1050
Ancillary Parts (line cover, wall bracket, etc.) $125
Electrical supplies (wire, subpanel, shut off box, wire and whip) $150
Other crap I had to buy and rent which I am not counting was about $200
Based on wattage usage my projected monthly cost to run this is somewhere in the neighborhood of $50/month in winter. So, all in, I think the ROI on this investment is probably going to be fulfilled by December of this year as I am looking forward to some air-conditioned summer days in the shop as well. I hope you find this write-up helpful.