im wondering as to why it is my a/c blows hot at start up or when my engine isnt revved up? when im idling you can forget about the a/c blowing cold. why is this? i have an electric fan setup and cant seem to figure out if this is something everyone goes through or not? any help would be appreciated. i would take it to Ford but they would blame it on the fans right away.

 

do your fans turn on with the AC? if not then thats your problem

 

At idle, your compressor is not pumping enough refrigerant volume to create enough cooling for the volume of air moving over the evaporator (the inside coils.) Options potentially include running an overdrive crank pulley, an undersized compressor pulley, or changing the compressor out for one with more cubic inches. No guarantee on what happens to the compressor when it is overdriven at high engine RPM. You can turn your inside fan speed down some and the vent temperature will go down, but it won't cool the total cabin off as well.

Also, recirculate mode helps a bunch.

The current F-150 has plenty of condenser air flow, even at idle, to condense the available refrigerant flow. E-fans will do nothing as far as air conditioning is concerned.

 

hmm thats weird but actually i think thats the problem my fans turn on at a certain temp. im not completely sure what that is now, but they dont turn on with the fans only when that temp is reached

 

I don’t have e-fans and my A/C runs cold at idle. I know this because when we go out for soft-serve ice cream we sit in the truck and eat it for 15min or so with the A/C pumping cold air. I thought e-fans would do the same thing, only more efficiently???

 

the efans could possibly be more efficient for the AC at idle since most fan kits run at one speed all the time, that is usually higher than the mechanical fan at idle. er not same speed per se, but flow (CFM) if you dont have the mechanical fan, and you have efans, and they are ONLY controlled by radiator temp, then your AC will not be cold on initial startup, because the radiator wont be hot enough to trip the fans on its own. that is why most kits include an AC circuit override that will turn the fans on when the AC compressor is on.

the bottom line is, if there is no air moving through the condenser at idle, then the AC will be HOT HOT HOT!! this is usually only a problem with vehicles with efans, at idle, at initial startup, if there is NOT an AC override circuit

 

Cold, or cool? With the fan set at 3 (I know you Lariat guys don't know what that means) there is a good 10 degree or so difference in vent temperature between idle and 1200rpm operation in my vehicle. It's possible that on a Lariat that the AC electronics drops the internal fan speed under idle conditions to maintain cold vent temperatures (I don't know, I don't have one.)

In terms of effectiveness, once the refrigerant is condensed and cooled a few degrees more (subcooling, in A/C terms, so it doesn't boil from engine heat in the lines before the expansion valve,) additional cooling does not make any realistic difference. The heat transfer is conducted by the latent heat of vaporization of the refrigerant. So additional fan power beyond that required to condense the refrigerent doesn't buy anything.

If the above condition is met (fully condensed refrigerant) I can't see the e-fans being more efficient. Turning mechanical power into electrical and back into mechanical seems like a loss prospect. That doesn't mean I don't appreciate them for maximizing engine output, where the stock fan is pumping more air than needed at high engine rpm. They are a definate winner in that scenerio because they are not constrained to operate at engine RPM.

Also, where there is not enough condenser airflow at idle from the engine fan, an E-fan would be very appropriate indeed.

If SVTRick's fans are not running whenever the A/C is on then that is another story altogether. Yeah, it'll blow hot then for sure! I would imagine that the install instructions for the fans would cover how to hook it up for A/C operation.

 

i sent an email to Mike Dunn to see if we can fix this matter

 

who is mike dunn?


(who is mike jones )

 

haha Mike Dunn runs Mad Enterprise, i think is the name of his company. anyways he made the controller i bought

 

ah yes ive heard a lot about that recently, it should have come with an AC circuit override, unless you got a REALLY cheap kit.

 

Cold with EATC set to 72°

 

Heres the reply to my email:

Erick,

I don't keep my notes but as I remember you are running Dual Fans.

This issue comes up occasionally with guys running dual fans in that one fan is insufficient to cool both the Radiator and the A/C Condensor. I have developed a cure with a minor reconnection.

I want you to remove the green wire from the switch on the A/C Condensor, tape it off, it will no longer be used. Run a jumper from the Blue wire that connects to the Radiator switch to the A/C switch. This way if the first fan is insufficient to keep both the Radiator and the Condensor cool then the second fan will kick in.

Another possibility, although remote, I have had one or two instances where for some reason, in order to give good cooling, the condensor needs to be kept cooler on some trucks than others.

 

Mine takes awhile to blow cold air after having sat in the hot sun all day. All of my other (GM) cars blow ice cubes out of the vents within 30 seconds. My truck has never done that. I've had the dealer evacuate it and refill it. Same problem. Others here have complained about the same thing. It's nice and cold after driving for 10 minutes, but it's very slow to cool down compared to every other car or truck I've been in. I use recirculate too.