transmaster

You will notice is takes about 8 hp to drive this compressor at max rpm. and it has about 26,000 BTU capacity.

http://www.sanden.com/products/performance7data.html













sa

KAH

Transmaster:

Could you please check the 8 hp input requirement.

Unless I am turned around in my calculations, for an output of
26,000 BTU/hr. one would have to have an input of 10.218 HP.

Thanks,
Ken H.

transmaster

Thanks for your interest, Go to this link and it shows the performance data on this compressor. http://www.sanden.com/products/performance7data.html

wde3477

Suggest that KAH is correct - 26,000 BTU is about 10.2 hp, using the conversion factors of 3412 BTU per kilowatt and 0.746 kilowatts per horsepower.

However, the trick is to remember that an air conditioner doesn't create or 'un-create' heat, it only 'moves' it - so that its rated output will (hopefully) be significantly higher than its energy input.

Even so - the energy efficiency ratio (EER) is about 4.4 BTUs per watt at its max rpm rating, about one-third of that required for new home A/C units (SEER = 13, where the 'S' stands for seasonally-adjusted).

Airflows across and the sizes of the respective condenser and evaporator coils, and the ambient temperatures and humidity also contribute to the overall system efficiency and the actual BTUs delivered.

Assuming that this compressor is being touted for its efficiency, the numbers may be fairly respectable in the scheme of things as compared to other units. If real estate weren't such an issue, suggest the overall energy efficiencies could be higher - but it just isn't feasible to stuff in a home-sized compressor, coils, and fans into most passenger vehicles.

Even so - 26,000 BTU is a just a bit over 2 tons of cooling (12,000 BTU/hr = 1 ton) - so the little unit is certainly capable!

transmaster

I am glad to see there are people here who are interested in the technical side of how things work on our beasties. One thing I wish they had in the manuals for our trucks is what in electronics is called "the theory of operation" This is a written description of how something works. Something I could sure use right now is the theory of operation for the A/C system on my truck. This sort of written example is really handy when you are trying to figure out why a system is not working. It is one thing to look at a schematic but to have a narrative is really nice.

mrrtpa4x4

New to this site, but hoping someone may have some ideas. I have a 2007 F-150 4x4 Crew Lariat. I have started having an intermittent a/c issue. The problem is the a/c cools just fine when it works. The problem is that at times the a/c is on, but the compressor won't kick in. Sometimes it kicks in immediately after starting, sometimes I have to drive the truck a block and it will kick in, other times it does not work at all for a day or so. I have taken the truck into the Ford dealer in my area and they could not locate the problem. The only thing they said is it might be in the dash controls. Has anyone had this type of problem, and what was the solution. Help, I'm melting in Fla.