How much does using the A/C effect power?
11-13-2002, 01:34 PM
#2
Registered User
When the compressor is running, it zaps about 5 hp.
It pressurizes the system up, then shuts off until the pressure drops below a certain level.
When it's shut off, it draws 0 hp.
When a car is cruising, it only needs about 25 hp to maintain speed on level ground... typically you're in a higher gear. This is why you notice the A/C cut in and out.
It pressurizes the system up, then shuts off until the pressure drops below a certain level.
When it's shut off, it draws 0 hp.
When a car is cruising, it only needs about 25 hp to maintain speed on level ground... typically you're in a higher gear. This is why you notice the A/C cut in and out.
11-13-2002, 02:45 PM
#6
Registered User
Originally posted by pellisS2k
In addition, the AC will shut off when you go WOT.
In addition, the AC will shut off when you go WOT.
BTW, the compressor has the same listed capacity as the 1999 CR-V, but has a maximum speed of 12,000 RPM instead of 10,000 RPM.
Trending Topics
11-13-2002, 05:32 PM
#8
I would be surprised if the compressor used more than 2 or 3 HP. Here's what I base this GUESS on:
1. 30 years ago my Dad worked on catalytic converter research, and I remember him telling me the cars he was testing only used about 15 HP to cruise at 60 mph, and we're talking about big american cars with no attempt made to be aerodynamic. If the compressor used 15 HP, your gas mileage would drop disgustingly low on the highway, since it would double the load on the engine.
2. A typical home window AC unit is rated between 12,000 and 15,000 BTU per hour, and I believe the conversion from HP to BTU/hr is about 4500 BTU per HP, so that fits the 2-3 HP guess if you assume the S2000 AC is a little less powerful than a home window unit. It has a bigger heat load to handle(lots of windows, no insulation) but has a MUCH smaller volume to cool, so I'm thinking maybe 8000-10000 BTU output is about right. Is there a spec in the shop manual for cooling BTU's?
I'm not sure about the WOT compressor cut-out, but I don't think there is one. I did not find any connection between the ECM and the AC controls or compressor clutch in the wiring manual, so I again GUESS that it's not controlled by the ECM. I do know that I ran several 30 minute sessions at Road Atlanta in June (hot as Hades) with the windows down (top up) and the AC on full-time. I don't remember the vent output getting warm on the long straights, but I may not have been paying attention.
.
1. 30 years ago my Dad worked on catalytic converter research, and I remember him telling me the cars he was testing only used about 15 HP to cruise at 60 mph, and we're talking about big american cars with no attempt made to be aerodynamic. If the compressor used 15 HP, your gas mileage would drop disgustingly low on the highway, since it would double the load on the engine.
2. A typical home window AC unit is rated between 12,000 and 15,000 BTU per hour, and I believe the conversion from HP to BTU/hr is about 4500 BTU per HP, so that fits the 2-3 HP guess if you assume the S2000 AC is a little less powerful than a home window unit. It has a bigger heat load to handle(lots of windows, no insulation) but has a MUCH smaller volume to cool, so I'm thinking maybe 8000-10000 BTU output is about right. Is there a spec in the shop manual for cooling BTU's?
I'm not sure about the WOT compressor cut-out, but I don't think there is one. I did not find any connection between the ECM and the AC controls or compressor clutch in the wiring manual, so I again GUESS that it's not controlled by the ECM. I do know that I ran several 30 minute sessions at Road Atlanta in June (hot as Hades) with the windows down (top up) and the AC on full-time. I don't remember the vent output getting warm on the long straights, but I may not have been paying attention.
.
11-14-2002, 09:18 AM
#10
Registered User
Join Date: Sep 2002
Location: EP
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
When I attended pursuit training at a Law Enforcement Academy they wouldn't let us use the AC, due to power robbing concerns. A few guys tried it anyway and ended up going a bit slower around the track. (and getting yelled at later when they had a puddle of water under their vehicle.) 