I wanted to post my experience upgrading my garage door to better control shop temp.
I live in So Cal. I have a West-facing garage door on my 3-car garage, which I have converted to a woodshop. When I bought the home 8 years ago, the garage temps got brutal in the summer. I like it around 70 degrees when I work, but the summer shop temps hovered around 90-95 degrees on a hot day.
One culprit was the old uninsulated steel garage doors. On one hot day, I measured the temp on the outside surface of the door at 128 degrees (which was about 30 or 40 degrees hotter than the ambient temp outside), and the inside surface of the garage door was 118 degrees on the panels (hinges were hotter). Only a 10 degree difference. Ouch. The garage doors were basically a 140-square-foot, 118-degree radiator.
A few years ago, I bought a garage door insulation kit from Home Depot. That made a big difference. I found another day when the temp of the outside surface of the door was around 130, and the inside surface of the door at the panels was a little over 100 degrees. Big improvement, but still a giant 100-degree radiator.
This winter, I had a set of Amarr R-19 doors installed. Wow. What a difference. Today is brutally hot (way hotter than those other two measurements described above), so I took some readings with my thermal imaging camera. At one point, the ambient temp outside was 110 degrees (yikes), and the outside surface of the garage door measured 148 degrees! Ouch. But the inside surface of the door at the panels was only 91 degrees. I wasn't working in the shop today, so I didn't run the AC; the ambient temp in the shop was 85 degrees.
Bottom line, the Amarr managed to keep the inside surface of the door 57 degrees cooler than the outside surface, and only 6 degrees warmer than the ambient temp in the shop (25 degrees cooler than ambient outside temp).
I have taken numerous other steps to cut the shop temp over the years. I replaced my fluorescent lights with LEDs, insulated the walls and ceiling, and added a mini-split AC. But until now, the AC still struggled to keep up on a hot day. With the giant radiator that was my old garage door removed from the equation, I'm pretty confident that my mini-split can keep me pretty close to the 70 degree target all day long.
Final point: The garage door experts spend lots of time talking about the seals and hinges as being the most important thing on a garage door. That may be true if you're fighting a cold climate or don't have a West-facing door. But with a West-facing door on a hot day, your biggest enemy is the sun's radiant heat beaming directly on the garage door, not the ambient outside temperature. That's why the outside of my garage door measures 148 degrees when the outside temperature is 110. Radiant heat on those big panels is the killer, because it turns those high-square-footage panels into giant radiators. If you live in a hot climate with a West-facing door, the most important thing is keeping that radiant heat on the outside of the door, which means as much insulation as you can stand. (It also means a white door with no windows.)
I hope someone finds my experience helpful.
I live in So Cal. I have a West-facing garage door on my 3-car garage, which I have converted to a woodshop. When I bought the home 8 years ago, the garage temps got brutal in the summer. I like it around 70 degrees when I work, but the summer shop temps hovered around 90-95 degrees on a hot day.
One culprit was the old uninsulated steel garage doors. On one hot day, I measured the temp on the outside surface of the door at 128 degrees (which was about 30 or 40 degrees hotter than the ambient temp outside), and the inside surface of the garage door was 118 degrees on the panels (hinges were hotter). Only a 10 degree difference. Ouch. The garage doors were basically a 140-square-foot, 118-degree radiator.
A few years ago, I bought a garage door insulation kit from Home Depot. That made a big difference. I found another day when the temp of the outside surface of the door was around 130, and the inside surface of the door at the panels was a little over 100 degrees. Big improvement, but still a giant 100-degree radiator.
This winter, I had a set of Amarr R-19 doors installed. Wow. What a difference. Today is brutally hot (way hotter than those other two measurements described above), so I took some readings with my thermal imaging camera. At one point, the ambient temp outside was 110 degrees (yikes), and the outside surface of the garage door measured 148 degrees! Ouch. But the inside surface of the door at the panels was only 91 degrees. I wasn't working in the shop today, so I didn't run the AC; the ambient temp in the shop was 85 degrees.
Bottom line, the Amarr managed to keep the inside surface of the door 57 degrees cooler than the outside surface, and only 6 degrees warmer than the ambient temp in the shop (25 degrees cooler than ambient outside temp).
I have taken numerous other steps to cut the shop temp over the years. I replaced my fluorescent lights with LEDs, insulated the walls and ceiling, and added a mini-split AC. But until now, the AC still struggled to keep up on a hot day. With the giant radiator that was my old garage door removed from the equation, I'm pretty confident that my mini-split can keep me pretty close to the 70 degree target all day long.
Final point: The garage door experts spend lots of time talking about the seals and hinges as being the most important thing on a garage door. That may be true if you're fighting a cold climate or don't have a West-facing door. But with a West-facing door on a hot day, your biggest enemy is the sun's radiant heat beaming directly on the garage door, not the ambient outside temperature. That's why the outside of my garage door measures 148 degrees when the outside temperature is 110. Radiant heat on those big panels is the killer, because it turns those high-square-footage panels into giant radiators. If you live in a hot climate with a West-facing door, the most important thing is keeping that radiant heat on the outside of the door, which means as much insulation as you can stand. (It also means a white door with no windows.)
I hope someone finds my experience helpful.