Bourbon County
Senior Member
RV LIFE Pro
I recently conducted an AC performance test on my 3661RL. It had been sitting for more than a week with ACs turned off, the only appliances running were the residential fridge and possibly the converter on occasions. I put my Hobo temp/RH data logger directly on top of the thermostat and set both ACs to 72 degrees. I was actually amazed at part of the results, and puzzled by others.
When I started the logging, the outdoor temp was 91 deg, the overnight low went to 73, and it was 93 the next day when I retrieved the data logger. The rig is parked with the broadsides facing due east and west, door side to east. The AC units are OEM from that vintage Dometics, 15K BTU rear, and 13.5K BTU front.
As you can see on the graph, it pulled the interior temp down from 94 to 74 in 3 hours, 20 minutes which is very close to 6 degrees per hour. This was the part that amazed me, I was expecting maybe half that rate. It looks like the temps started increasing around 8:00 AM and climbed to 78 degrees and never recovered, this is the puzzling part.
At this point, I'm not sure if my test method was accurate; I didn't lower the blinds. There's a small ridge with some tall trees about 100 yards east of the parking spot and the rising sun comes over the trees in full around 8:00 AM this time of year. That side of the rig has the most window area and I'm hoping solar gain contributed to the temp rise.
We're having a few days of pleasant temps but supposed to be back in the 90s in about a week. I'm going to repeat the test with some different conditions. The blinds will be drawn and I'm going to start around 3-4 PM. When traveling, we normally try to be at our destination and set up around that time of day. I have another data logger on order and will run it simultaneously at the (front) bedroom thermostat.
The graph is a screen shot in the most literal sense; apparently you can't view it without having the Hobo software running. I made a picture of it to post. I believe I cropped it out, but the black line is temp, the blue is RH.
When I started the logging, the outdoor temp was 91 deg, the overnight low went to 73, and it was 93 the next day when I retrieved the data logger. The rig is parked with the broadsides facing due east and west, door side to east. The AC units are OEM from that vintage Dometics, 15K BTU rear, and 13.5K BTU front.
As you can see on the graph, it pulled the interior temp down from 94 to 74 in 3 hours, 20 minutes which is very close to 6 degrees per hour. This was the part that amazed me, I was expecting maybe half that rate. It looks like the temps started increasing around 8:00 AM and climbed to 78 degrees and never recovered, this is the puzzling part.
At this point, I'm not sure if my test method was accurate; I didn't lower the blinds. There's a small ridge with some tall trees about 100 yards east of the parking spot and the rising sun comes over the trees in full around 8:00 AM this time of year. That side of the rig has the most window area and I'm hoping solar gain contributed to the temp rise.
We're having a few days of pleasant temps but supposed to be back in the 90s in about a week. I'm going to repeat the test with some different conditions. The blinds will be drawn and I'm going to start around 3-4 PM. When traveling, we normally try to be at our destination and set up around that time of day. I have another data logger on order and will run it simultaneously at the (front) bedroom thermostat.
The graph is a screen shot in the most literal sense; apparently you can't view it without having the Hobo software running. I made a picture of it to post. I believe I cropped it out, but the black line is temp, the blue is RH.
