Quote:
Originally Posted by gmtech16450yz
3- The brand new (2018) Coleman 15k that is on the roof of my 2018 RV is LESS EFFICIENT WHEN MOVING as it is when stopped. Read my story about the rest stop in Utah. What I learned almost 3 decades ago still applies today 100%. I monitored amperage and inlet/outlet temps for 3 days in 100 degree temps. Amperage goes UP and outlet temps GO UP when you're driving at freeway speeds. Slow down to a stop and amperage drops, along with outlet temps.
The short explanation for this is the fact that the basic design has a harder time getting airflow in and out of the condenser and compressor area when there's a 60mph wind going over the entire unit. This to me is insane. Why on earth would you not exploit the benefits of airflow? That 60mph wind could totally eliminate the need for the condenser fan end of that 1/3hp electric motor. I monitor AC high side pressure on the engine AC system. Sitting still AC pressures (which track roughly the same as temperatures btw) will go as high as 300psi. (That means the high side lines and compressor are all around 300 degrees!) At 60mph, those pressures will drop to roughly half that, around 150psi. That's because the AC condenser is taking advantage of that free airflow. That's why your car AC works much better when moving. as it should. The fact these roof AC's don't take advantage of moving air is (in my opinion) insane.
|
They use the same AC units on trailers and 5th wheels as motorhomes and nobody runs those going down the road. They're not going to make a new design just for motorhomes if the legacy design is "good enough">
Thor Forums
