Vent temp update: I think I'm gonna survive this summer!

[mthomas58]

Spring has arrived in Atlanta with recent daytime highs in the mid 80's renewing my obsession with improving the performance of my stock A/C with several DIY tweaks. Early performance results are so encouraging I just had to post some #'s. This is my daily driver and I seem to be in one of the few jobs still requiring a suit, therefore, I gotta have decent A/C.

When I bought the car last July the A/C was working poorly with vent temps in 60's+. Local wrench replaced evap blower motor, front condenser motor, two hoses, drier and rear condenser.

After the repairs, I got low end vent temps in the mid 30's to low 40's, but I was convinced with some tweaking I could do better.

This is what I've done to date:

Added 7.5" spal fan to rear condenser (440CFM)
Added 4" spal fan to pass. floorboard at evap intake(125 CFM)
Cleaned evap coil and evap box (in-place,without disconnecting)

Hear are the early season results:

I'm measuring vent temps with a $10 indoor/outdoor digital themometer from Target with the outdoor sensor inserted about 3" into the center dash vent. On this mornings' commute with 66 degree ambient temp, the lowest fan speed setting and the max cool thermostat setting, I got the following vent temp results:

The compressor consistently kicked in at 40 degrees (activating the aftermarket fans). Vent temps consistently dropped to 28 - 29 degrees before compresser cycled off and temps would drop to about 25 before heading back up to 40 when the compressor cycled back on. Went throught about 12 such cycles on the way to work with great consistency on cut on and cut off temps. I realize that the lows will be higher with ambients above 90 but I'm very encouraged!

Will be adding two more small fans on the rear condenser shortly.

Related threads:

Adding 3 fans to rear A/C condenser

http://forums.pelicanparts.com/showthread.php
s=&threadid=336402&highlight=evap+assist+fan

Calling all A/C Experts: Evaporator froze up today?

[mthomas58]

Did some more tweaks this weekend. Mounted addl 5.1" spal fan to the rear condneser(313CFM) (I'll stop for now as I do not think an addl 4" fan will be needed). I also opened up the evap box again and put foam baffles on the short sides to block air from bypassing the coil. Evap to vent hose came apart so I found a rubber sleeve in the plumbing dept of Home Depot which did the trick. The 20 year old hose must have been leaking based on the air volume now. If fact, it's so good now that I'm going to table plans to find a higher volume evap fan motor.

Today is a similar day in ATL with ambient temps in the mid to high 60's. My weekend tweeks now allowed vent temps to get down to 20 degrees on the way back from lunch. I guess I will now need to back off the thermostat setting to keep the coil from freezing up. My thermostat may not be working as it should because the sensor probe is laying on top of the coil (not inserted into the coil) but it's working great so I'm not going to touch it. Cycle temps changed a little - on at 36-37 and off at about 24-25.

July and August, I'm ready for ya!

[SCWDP911]

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