More Condenser Air = Colder Temps

white99c2 · 09:31 AM

My car a '79 SC with a rotary compressor and a full charge of R12. In the heat if 110+ degree Arizona all I could get was 60 degree vent temps with a working factory setup including the front condenser fan.
Added a 9" rear condenser fan, 800 CFM's, added 3 computer muffin fans right over the front condenser in the space right on top of it then re-installed the factory fan over them. Added another muffin fan as a return to the evaporator right behind the passenger floor board.
The result in the same 110+ temps, I now get 50 degree temps out of the vents, good not great, my neck stopped sweating while I'm driving.

The computer fans over the condenser is hokey pokey I know, I just wanted to prove to myself that if I get a good heat exchange on that front condenser I could get colder vent temps and I do. Not sure if the rear fan is making all that much difference. The air blowing under that front condenser is pretty hot.

So what type of high CFM fan can I adapt over the front condenser utilizing the existing or modified version of the fan housing?

DRACO A5OG · DRACO A5OG's Garage

SPAL has some fans that may work.

Could you post some pics? I've been thinking of doing the same

white99c2 · 07-18-2009, 10:11 PM

I've got it all buttoned up and really dont want to take it apart again. The fans are small 4"x4" units, I wired them together and tied the hot and ground into the leads of the factory fan. Very Basic, what is SPAL?

DRACO A5OG · DRACO A5OG's Garage

Understood and I don't blame yeah.

Here is the link to SPAL http://www.spalusa.com/store/main.aspx

mthomas58 · 07-19-2009, 04:50 AM

Good source for fans here:

http://www.the-fan-man.com/

plain fan · 07-19-2009, 06:33 AM

First, congratulations on getting that type of cooling with your car. IMO, I think you should upgrade the fans to the spal design. I understand not wanting to take everything apart but if you really want improvement then you need to bite the bullet and upgrade. You also need to remember that the front condensor (and the rear) are pulling in hot ambient air across the condensors. This is most true for the front condensor when you consider its location on the car in relation to the road. You could also add additional condensors that should help in cooling as well. I would recommend searching the forum for A/C projects and upgrades as this is a well discussed topic. Let me know if you have any questions.

white99c2 · 07-20-2009, 04:19 AM

I found a spal motorcycle fan on eBay that pushes 313 CFM's. My question, is that more than the factory fan pushes? I can fabricate an enclosure for the duct to the front of the car and fan. I don't want to take a stab in the dark. What CFM rating is the factory front condenser fan?

JMH82SC · 07-20-2009, 05:10 AM

I read a post about replacing the condenser blower (motor only) with the fresh air blower motor in the front condenser housing. The motor for the fresh air blower is the same size and mounting is the same as the stock motor but turns more RPMs= more flow past condenser. I have a friend who has done this and you can tell it is pushing more air but just how many CFM I have no clue.

Wil Ferch · 07-20-2009, 01:27 PM

This is the second post in as many minutes of looking over this board.... where I see a question on CFM's for fans. Big caveat--> you need to understand fan "curves". Look at the SPAL website as an example.

Fictitious numbers here but the curve goes something like this
500 CFM at 0.0" water column static pressure
400 CFM at 0.1"
300 CFM at 0.2....

....or somesuch. The more resistance of the air through whatever it cools ( tubing, front face of an oil cooler, whatever)...the less flow. If you want to compare fans, make sure they are being compared apples-to-apples.