Electric AC compressor?

[EcoCivic]

Originally Posted by Hersbird

Just running your a/c is the least expensive solution by a factor of 100 I bet. What exactly do you mean kills your MPG? Going from say 40 to 35 isn't that big of a deal. Maybe $100-$200 a year. However you charge the battery will take some energy too. If you really want to get 40+ and run your A/C just buy a used Prius for probably less than any wierd conversion would cost. Plus I bet adding 300 pounds of battery might also hurt your MPG similar to running the A/C on the belt.

Good advice. My goal isn't necessarily to save fuel just for the purpose of saving money, it's also a game to me to see how many MPG I can get. The weight of the batteries is a great point too. Initially I was thinking I could maybe get away with 100 pounds of batteries, but it looks like that may not work out.

[serialk11r]

On my nearly brand new Scion FR-S I had a few years ago, I remember that the heater leaked heat through the blend door. I clearly remember some of my parents' new cars doing that when I was a kid too. I thought it was a normal feature of all cars, but I have since seen a few cars (including the one I have now) that don't blow warm air, which is SO nice. The sun puts enough heat into the cabin already, engine heat is very unwelcome :/

As far as I can tell, every single car that has the intake below the windshield will blow air at you with the fans not on unless you turn on recirculate, because the base of the windshield is a high pressure zone. If the seals or plastic panels blocking things off are missing or damaged, you can be sucking in engine bay air. Some cars tuck the intake elsewhere and won't have air blowing at you on the freeway.

[cRiPpLe_rOoStEr]

Originally Posted by serialk11r

every single car that has the intake below the windshield

Nowadays it's hard to find any car with the intake somewhere else. Even some classics had a retractible air intake at the cowl, right in front of the windshield, yet it didn't pull any warm air from the engine bay.

[EcoCivic]

Just got back from driving and heat intrusion is a LOT lower with the under hood part of the fresh air intake taped off even though I kept recirculate on the whole time. Shutting the AC off during acceleration is now much more tolerable. The vent air still feels somewhat warmer than cabin air when the AC isn't on, but it no longer feels like the heat is on.

One of my next projects will likely be removing the wiper cowl, maybe drilling small holes for additional air intake to compensate for the blocked off underhood portion of the vent, insulating the cowl portion of the firewall, and properly sealing the little gaps around the wiper cowl with foam strips or some other type of sealant material to reduce engine heat intrusion as much as possible.

Actually since I almost always use recirculate in the summer anyways I may try taping off the exterior air inlet also to prevent hot outside air from getting sucked/pushed into the cabin and see if I like the results. About the only time I use fresh air mode in the summer is for the first couple minutes after I get into the hot car when outside air is cooler than the air in the cabin. I would prefer for no outside air to enter with recirculate on while still retaining the option to use outside air mode with the press of a button, but I may be better off just blocking off the exterior inlet entirely during the summer since it likely lets a lot of heat in. If I don't like the result all I lost was a couple minutes of my time and a few cents of tape.

[cRiPpLe_rOoStEr]

Originally Posted by EcoCivic

About the only time I use fresh air mode in the summer is for the first couple minutes after I get into the hot car when outside air is cooler than the air in the cabin.

With the AC on or off?

[EcoCivic]

Originally Posted by cRiPpLe_rOoStEr

With the AC on or off?

Usually with the AC on. Initially I use fresh air mode when the interior of the car is very hot as it's easier for the AC to cool 100 degree ambient air than 120+ degree cabin air. Once the interior cools off to roughly outside temp, I switch to recirculate.

[MeteorGray]

I live in hot-and-humid Louisiana and use the air conditioner for most of the year, always in recirculate because it's counterproductive to bring in un-conditioned-air.

I might lose a few MPGs because of the AC's load on the engine, but it's worth every one of them!

My Mazda3 has a button to press to disengage the AC compressor, leaving the fan to drain the ducts of cool and dry air until it warms up again, and I find myself occasionally pushing it on-and-off when the temperature and humidity aren't too bad in a bid to save a few drops of fuel. Probably not worth the effort, but hope reins eternal.

The 2.0L engine doesn't seem to be very affected by the extra load of the AC, as I can't feel the compressor cycling, although I sometimes can hear the "click" as it cycles on-and-off when idling.

[cRiPpLe_rOoStEr]

Originally Posted by MeteorGray

I live in hot-and-humid Louisiana and use the air conditioner for most of the year, always in recirculate because it's counterproductive to bring in un-conditioned-air.

My grandparents who live in Amazon do it too, yet I'm not sure if they keep it always in recirculate. My grandmother used to smoke, so once in a while I would see her driving with the A/C on and windows down while smoking

[EcoCivic]

Just taped off the exterior HVAC air intake on the cowl as an attempt to prevent hot outside air from getting forced into the cabin and it didn't work. With the fan off, air still comes in through either the vents or the interior HVAC intake behind the glovebox depending on whether recirculate is on or off. The amount seems to have been somewhat reduced though. Trying to figure out where air could be entering.

[California98Civic]

Originally Posted by EcoCivic

Just taped off the exterior HVAC air intake on the cowl as an attempt to prevent hot outside air from getting forced into the cabin and it didn't work. With the fan off, air still comes in through either the vents or the interior HVAC intake behind the glovebox depending on whether recirculate is on or off. The amount seems to have been somewhat reduced though. Trying to figure out where air could be entering.

On my Civic that air is not hot if I have the HVAC temp setting on the "cold" side. On the 6th Gen Civic, the temp selector cuts off the hot coolant from circulating into the heater core.