Cool down test, I'm amazed

[Jerry Liebler]

This is fun, the newly installed split heat pump is amazing.  I decided to try a cool down time test.  It's sunny and the outside temp is right at 90 and rh is 43%.  The inside of the bus is the same, I ran the fantastic fans for 15 minutes circulating outside air inside.  I shut the fans off & closed them up then started
both AC units, the 10,000 BTU in the bedroom and the 18,000 BTU up front. 5 minutes later the bedroom was down to 70 and the rear unit started cycling.  After 30 total  minutes the front was down to 70 and the front unit   began it's first rest.  All the while I was watching the load amps on the inverter panel. The peak with both on hit 22 amps ocasionally but usually sat at 20 or 21. When the rear compressor was off but it's fan still on and the front solidly on the load was 14 amps or less  I read the interior temperatures on the thermometers that are in the thermostats for the heating system, one is on a front wall of the bedroom the other is on the wall at the rear of the dinette.   It sure was worth the challenge to get that front unit installed.  Anyone done a similar test with their system?
Regards
Jerry 4107 1120

[jjrbus]

Jerry as long as you are having fun!! Try starting your cooling test with the roof vents open with the fans off. I do this in my bus, I have never tested it but it seems to cool quicker. I do the same thing in my toad, I leave a window slightly open and the car cools quicker.
 

[Len Silva]

Jerry, that's very impressive.
The next test is driving west (into the sun) on a hot afternoon.  The cooling load with a constant 60 mph wind will rise substantially.

Len

[DavidInWilmNC]

Jerry,
I'd love to see some pictures of the inside and outside units and how you mounted / installed them.  Although my OTR A/C works fine, I'd still like something a bit quieter and more efficient (lower power consumption) than what roof mount RV A/C's or heat pumps offer.  I'm currently installing a ducted window A/C in the rear bay for the bedroom; if 10K BTU's are working for you that well, I imagine my 8K BTU unit will suffice.  I'm sure glad somebody is testing out what I'm interested in using on my bus!

David

[Nick Badame Refrig/ACC]

Jerry,

I'd like to see that test on the east cost at 90 deg. and 90% relative humidity.

Let us know if you ever come to the east.

From 20 years expierence with ductless splits, thats their only down fall. They are not so good in the dehumidifacation Department.

Only because they move air past the evaporator too quickly. I actually have customers that say that it seems more humid

inside the home then outside. I have a Sanyo 18,000 btu heat pump in my addition of my home and they are correct

about the humid feeling. The DS cpmpany's claim that they are not designed to dehumidify...Go figure!

Nick-

[Nick Badame Refrig/ACC]

Jerry,

Also keep in mind that if your bus is listing in a not so level site, the ductless splits only drain from the right side,

and the pans are only 1 1/2" high. Maybe there is a way to install a second drain in the pans?

I wouldn't want you to start soaking your interior..

Good Luck
Nick-

[Jerry Liebler]

Nick,
    I am almost in the East, Kentucky.  Now I'm glad that I accidental got the rear (left as you face it) end about 1/2" too high when I mounted the indoor unit.  As I understand it the relative lack of dehumidification is more a consequence of the manufacturers targeting higher SEER with higher evaporator temperature and more air flow.  The only options are, as  I mentioned in a private email, avoiding overcharge, and slowing the fan speed.  I'm waiting for my new thermocouple thermometer to accurately measure the superheat which I believe is too low due to overcharge.  My suction line pressure is 115 psig which my r410a chart says is saturated pressure at 39 degrees f  but I don't know the line's temperature.
Regards
Jerry 4107 1120