13.5K BTU vs 15.0K BTU Air Conditioners -- HOW????

[TenOC]

Question for my RV Air Condition Experts.

What is the difference in 13.5K BTU and 15.0k BTU? I know what a British Thermor Unit is. My question is HOW does the A/C achieve the difference in the RV? What is the real effect to the person inside the RV?

Given the same outside and inside temperatures.

1. Does the larger BTU unit blow more volume of air? More CFM?

or

2. Does the larger BTU unit blow colder air? I thought that under ideal conditions the A/C should cool the air only about 5 to 10 degrees.

[dougrainer]

This is from RVP's Technical. So, I AM NOT WRONG. I just use the Temp diff to document for the customer. I take an AMP reading with temp correction for the correct performance. Doug


An ideal cooling system should give you an output temperature range of 16 to 22 degrees lower than the temperature taken in at the filter. Humidity is a significant determining factor in this temperature difference.
You can test the temperature difference by taking a reading at your filter and the first register where air is leaving the system. Please use the same thermometer at each location.

[2oldman]

dougrainer wrote:
Differential is the Temp difference between the hot air intake vent and the nearest cold air exhaust vent after 15 minutes running. A correctly installed AC will have 18 to 22 degrees difference and will continue to the same as the temp in the RV drops...or . I guess, WHY is it important for you to know this answer?????

Because I think everyone who says this is wrong. See my linked post above.

Do I have some sort of freak a/c?

[dougrainer]

2oldman wrote:

Mandalay Parr wrote:
They all have about an 18 to 20 degree differential.

Differential to what?

Differential is the Temp difference between the hot air intake vent and the nearest cold air exhaust vent after 15 minutes running. A correctly installed AC will have 18 to 22 degrees difference and will continue to the same as the temp in the RV drops. AS to the Difference between 13.5k and 15k. MOST 15k units have larger diameter Copper tubing and I do not believe the evap or condenser are a different size. DO NOT CARE. The only thing you need to know is they have 13.5k or 15k. It does not take much more to get that extra 1500 btu's. It will NOT blow colder air. It just moves the volume of air thru a colder evaporator . I guess, WHY is it important for you to know this answer?????? The 15k units will pull about 2 amps MORE than a 13.5k. The compressor may be slightly more powerful, but since we have not had compressors as a service item for over 25 years I do not know. You really need to contac RVP or Dometic for the answer. Doug

[2oldman]

Mandalay Parr wrote:
They all have about an 18 to 20 degree differential.

Differential to what?

[Mandalay_Parr]

They all have about an 18 to 20 degree differential.
The larger BTU would blow more air and have larger coils.

[Cloud_Dancer]

Doug Rainer has answered this specific question here previously. I can't truly recall, but it could be that it has a slightly larger condenser and/or evaporator. BTW my motorhome has two 15,000 btu Penguins, and there's been times when I could've use another 5,000.....(sunbelt summers, you know).

[2oldman]

TenOC wrote:
? I thought that under ideal conditions the A/C should cool the air only about 5 to 10 degrees.

Post I made yesterday.

Can't directly answer your question, sorry. But there sure seems to be a lot of confusion on how these a/c's operate regarding temperatures. Mine is a Duotherm Briskair (which I think is 13.5)