Temperature Differential for Coleman Mach AC

[RamTX]

Have a Coleman Mach 15000 BTU AC unit. Does anyone know what the temperature differential between return air and discharge air is? I know on cars and houses it should be about 20 degrees F. Thanks.

[kellertx5er]

TXiceman wrote:

In the south, anything over 30' length needs two A/C units to have a chance of keeping cool in the summer.
Ken

I sure wish Keystone had known that when they built our 34' Outback Sydney. Shade is my best friend.

[TXiceman]

Normal difference between inlet and outlet at the unit is 18 to 20 degF with the fan on high speed.

If you are getting 25 to 29 degF difference, you have a problem. First thing to look at is reduced air flow, low fan speed, dirty filter, leaking from inlet to outlet.

In the south, anything over 30' length needs two A/C units to have a chance of keeping cool in the summer.

Ken

[C_Schomer]

My last 1998 Dometic did 29 after a good cleaning and sealing the ducts and dividers. I've been working on my 2008 Dometic but I'm not ready for the big test.

[RamTX]

Great responses all-info will definitely help determine if unit is working at peak efficiency.

[billmac]

I have recently cleaned the exact same unit. Mine is 25 degrees blowing straight down. Rv ducted air can be restrictive and change the numbers.

[mdamerell]

If I read right that's about a 34' trailer. In TX with only 1 A/C unit may be asking too much. You might look at adding a 2nd A/C unit. We found it made a big difference on the 90 plus days.

[Old-Biscuit]

The following is a statement from Dometic concerning RV A/C

"The ability of the air conditioner to maintain the desired inside temperature depends on the heat gain of the RV.
Some preventative measures taken by the occupants of the RV can reduce the heat gain and improve the performance of the air conditioner.
During extremely high outdoor temperatures, the heat gain of the vehicle may be reduced by:
1. Parking the RV in a shaded area.
2. Using window shades (blinds and/or curtains).
3. Keeping windows and doors shut or minimizing usage.
4. Avoiding the use of heat producing appliances.

Operation on High Fan/Cooling mode will give optimum or maximum efficiency in high humidity or high outside temperatures.
Starting the air conditioner early in the morning and giving it a "head start" on the expected high outdoor ambient will greatly improve its ability to maintain the desired indoor"

Here is what RV Products has to say about evaluating Coleman-Mach A/C...LINK


Vent covers, windows, slide-outs, thin walls with only just so much insulation etc. ALL contribute to heat gain in an RV

15-20*F differential is the norm.
BUT remember that is not outside air temp to inside air temp
IT is the temp differential between return air (sucked from inside rig) to discharge air (blowing out of A/C duct)

Just how cool the inside of rig gets is dependent on that heat gain factor
temperature

[Francesca_Knowl]

No performance difference between RV/house AC. They all work on the same principle.

[rtazz17]

About the same