Single Fan for Engine Cooling and Airconditioning - Fuel Economy, Hypermiling, EcoModding News and Forum

bobdbilder · 01-03-2016, 08:34 AM

I just came across this thought accidentally. My engine radiator fan is not working. I think its a faulty relay. But its ok. As long as I keep my airconditioning switched on. I have been running on like this for a week and the temp gauge never hits half way mark. I have also removed the weather strip that seals hot air from coming through the windshield gap. This helps hot air flow out of the engine bay. Of course, I drive at speeds below 90km/h and where I am at, the temperature never goes below 30 degC. When the car idles there is a degradation in the cooling air but not unbearable.

I realized newer cars have only one fan, typically the engine radiator fan. There is no dedicated fan for the aircond. I think the fan is switched on by both condition; hot coolant or aircond control. Where the aircond fan used to be, it is substituted by rubber flaps. I think it closes so the central fan sucks in far wider area at low car speed.

The savings is both in reduction of electrical load and minimal savings in weight due to deletion of one fan. But this modification can be done on older cars too. What do you guys think?

cRiPpLe_rOoStEr · 01-03-2016, 01:45 PM

IIRC every vehicle with air conditioner still has a dual-fan setup. At least I haven't seen any without a fan dedicated to the air conditioner condenser but not eliminating totally the radiator fan.

bobdbilder · 01-04-2016, 09:56 AM

I am trying to post a URL link for an local model now discontinued except for export to Egypt. I had a much similar setup on my previous car.

Somehow I have problem in using the URL button. Original APM Radiator Fan Motor, Fan Blade and Housing Panel Proton Gen2 AT(2 Pin), ZhaPaLang e-Autoparts

And I cant even use the picture button so bare with me. I'll probably paste another picture once i get hold of a proper laptop.

Or is this only available on Proton cars? Oopsies.

redpoint5 · 01-04-2016, 10:02 AM

All of my vehicles have 2 cooling fans; one for engine coolant, the other for the air conditioning.

Your car should still reach normal operating temperature when running the air conditioning fan, and if it isn't, you may need to replace your thermostat.

I'd diagnose the reason why your coolant fan isn't turning on and fix it.

bobdbilder · 01-04-2016, 10:14 AM

I tried replacing the relay today and it still wont work. The fuse is ok. So it might be afterall a faulty fan. But I am not worried. The temp gauge has an independent sensor from the one that activates the fan. So far it is not indicating more than half. I am not worried, but excited for the possibility of using only one fan.

Here is another link to an American company which did have a modification kit. The link to picture is dead but the description is good enough to explain. Single Electric Cooling Fan Dual Relay Kit | American Autowire

user removed · 01-04-2016, 10:38 AM

My 2015 Mirage with factory AC (auto climate control) has a single fan.

regards mech

Frank Lee · 01-04-2016, 10:47 AM

Nothing I've ever owned (besides Moon Unit) has had dual fans.

TimV · 01-04-2016, 11:12 AM

My car is a triple fan :P

1 big belt driven cooling fan, and 2 smaller electrical AC fans...

Miller88 · 01-04-2016, 03:59 PM

How could one be dedicated to specifically the AC condenser ... unless it was placed right on it. Usually the fans are behind the radiator, which is behind the condenser.

My Focus has one total fan.

The Cherokee has two. One electric and one belt driven.

Piwoslaw · 01-04-2016, 04:14 PM

Quote:

Originally Posted by bobdbilder

I realized newer cars have only one fan, typically the engine radiator fan. There is no dedicated fan for the aircond. I think the fan is switched on by both condition; hot coolant or aircond control.
[...]
The savings is both in reduction of electrical load and minimal savings in weight due to deletion of one fan.

My P307 has A/C (the condenser is right in front of the radiator) and only 1 fan. The fan kicks in when the coolant temperature reaches 98C. If A/C is active, then the fan keeps coolant temperature below 82C, which is a bummer if you are trying to keep the engine running hot for FE.

Ideal would be if the A/C condenser and radiator were independent (not in front of each other, but side-by-side and walled off), with their own openable grille blocks and fans. But then you have the weight penalty and the circle closes.