All electric aircon any good

[Nick]

Hi,

Trying to save myself some work and complexity does anyone have any experience of this system and will it be any good.

Maxi Kooler I AC and Heat Unit NOW ALL ELECTRIC!

Thanks

Nick

 

[Phil]

Nick:
No experience with this unit, but a couple of things set me thinking right away.
Seems like the price Is really cheap, and I don't see a compressor there in the usual fashion.
I would be suspect of the current draw that a system like this might have, and I would suspect output to be conversely low.
Might be a good thing to see the mechanical/electrical specs on this unit as that may be the deciding factor.
Most units run at least double the price, and some over $1000.00
Just my 2c
Cheers
Phil

 

[Ron McCall]

I think that the controls are electric. as opposed to cables to operate the heat and defrost.
I think that you would still need a compressor,condensor,hoses etc....

 

[Ron Earp]

If it is indeed all electric, that is not just electric controls, then it is probably using a Peltier device (TEC) to cool water driven through a heat exchanger. Speaking from a lot of experience(s) with TECs you'll never be able to cool air enough with one of these to make a difference in a car. And, if you were bound and determined to be "all electric" you'd need multiple, very large (>300W) TECs with huge current draws (25+A per TEC) and multiple heat exchangers and a lot more hardware than in that picture.

There isn't any free lunch. If you want a working AC unit in your GT40 then you'll need to bite the bullet and get a proper car system. Just don't make the mistake of putting the condenser in the engine compartment like some folks have done. Use long lines, route them properly, and get the condenser out into the fresh air flow.

If you ask me someone

 

[Seymour Snerd]

If you ask me someone

Ron, what were you going to say?

Just for completeness, there is a probably workable but difficult and expensive way to achieve this: Tecumseh/Sierra (Featured Product) makes a hermetic compressor that, with its controller, costs about $1,200. Then you add a ~2,000 W inverter to boost 12VDC to 120VAC, rectify that and drive the compressor with it. But to make that work you need a ~200A alternator. Of course an alternator that size needs either dual v-belts or serpentine drive. etc. etc. etc.

I looked at that for a while and then just bolted up my belt driven R134A compressor....

 

[Nick]

Hi guys,

Thanks for the very useful advice, didn't take long to get the answer, if Heineken did forums it would be GT40s.com. Ron I take it the best place for the condenser is in the front.

Regards

 

[Jim Rosenthal]

The best place for it IS out front. The problem is that it has to share the air flow with the engine cooling radiator, which is usually right in back of the AC condenser. The other problem is the huge wash of hot air that comes back over the car, from the engine cooling radiator. It is a lot more than you think it is...I vividly recall noticing this in my Ferrari Mondial (mid-engine, front mounted radiator) and a friend's 328, and a 512 Boxer- huge wash of heat coming back from the radiator vents, rather surprising in its' volume and intensity.

Mid-engine cars are prone to this sort of difficulty with AC systems. The evaporator is inside the passenger area, the compressor is in the rear, the condenser is in the front. This means long runs of refrigerant piping which diminishes efficiency quite a bit. The fact that any of these systems work is somewhat miraculous in and of itself.

The single way that I have personally seen to improve one of these systems is to mount the engine cooling radiators at the back of the car, on the sides. I think the Ferrari Testarossa was the first one to do this, in 1985. TR airconditioning is much better than any previous Ferrari. The AC condenser is still out front but the fact that the engine radiator doesn't exhaust hot air which then washes backwards over the rest of the car makes the job of the AC system much easier. There does not seem to be a way to cool a GT40 engine using rear-mounted radiators; the car was not designed that way and to incorporate them would not be practical within the original design.

The front-mounted AC system condenser also makes the engine cooling radiator less efficient. Frankly it is a perfect storm setup for an overheating engine AND an AC system that doesn't work very well at all. I have only been in one GT40 which had AC, an ERA car, years ago, and I was not impressed. I think the modern ones are much better- better compressors and better insulation on the pipework. But it is still not a great setup for AC. The solution may be to wear a lot less clothing. Or to acquire a female passenger who should wear a lot less clothing.

 

[Ron Earp]

Mid-engine cars are prone to this sort of difficulty with AC systems.

I think it might be more accurate to say mid-engine cars from boutique manufacturers (F-cars, etc) and/or home builds have this problem.

My Pontiac Fiero was nothing short of nipplerific for AC, would absolutely freeze you in 100F weather (and it had a sunroof with no inside cover). I've been in MR2s that are exactly the same. I think the large volume manufacturers that have a lot of experience with HVAC have no trouble building in the correct size evaporators, condensers, compressors, and properly insulate all of the tubing. My Lotus Esprit - no chance, wouldn't cool for squat.

Combine small production (particularly if European based and not understanding of the American's definition of Air Conditioning), with limited parts bin availability and engineering knowledge, along with a mid-engined design and you get something less than stellar. Heck, the last BMW and VW I owned (1998 and 2000 MY respectively) really didn't cool as well as I'd have liked and both were in tip top shape. Neither cooled like my F150 going on six years with no maintenance.

 

[Jack]

My Pontiac Fiero was nothing short of nipplerific for AC, would absolutely freeze you in 100F weather (and it had a sunroof with no inside cover). I've been in MR2s that are exactly the same. I think the large volume manufacturers that have a lot of experience with HVAC have no trouble building in the correct size evaporators, condensers, compressors, and properly insulate all of the tubing. My Lotus Esprit - no chance, wouldn't cool for squat.

Go for the LARGEST condensor that will fit in the space available, Both compressor and evaporator should be sized to work together. Given the relatively small amount of cubic feet to cool, small sedan components work well. Better (more efficient) should a larger condenser be used. Let's not forget proper insulation of the refrigerant tubing either. IMO..

 

[Dalton Veitch]

A couple of comments from me (I've some experience in designing air conditioning for a living, though not in cars). There is no problem with long runs of refrigerant piping provided it is sized correctly and if the flexible sections are modern barrier type (not the deliberately perforated type as on old (80's) Porsches), and if it is vacuum pumped for at least 3 hours to boil off all residual moisture before charging with refrigerant. Yes, there will be slightly more losses, but this means more input power from your motor to the compressor. It can still freeze your tits off. The Countach has radiators and condensers behind the cockpit, well before the Ferrari I believe. Not good cooling performance in this position though. You just cannot beat radiator and condenser sitting at the front in the main air stream. I agree that hot air onto the footwells and windscreen is an extra heat load, but the system can be sized to handle it. I know that the DRB air conditioning in Australia works very effectively, despite our steamy hot days.
In the referenced advertisement, I'm sure the "electric" refers to the controls, particularly the heater valve control, where electric is more sophisticated than a simple pull cable. The hot rodders are moving more to electric controls.

 

[Jim Rosenthal]

Fair enough. Actually on the Testarossa the AC condenser IS at the front of the car, but the engine radiators are at the back. TRs have good AC. And I agree that the boutique manufacturers don't do as well on AC; on volume production cars, even those with mid engines, the AC works a great deal better.

How good is the AC on a Superformance GT40? I have not been in one to find out.

 

[DaveM]

A/C in Superformance 40's is a little better than marginal, but certainly not up to mass produced sedan standards. At best my cockpit is 10 degrees F cooler than ambient, but only if the car is moving. Stop and go traffic means close to ambient. Would agree with all the analysis about front radiator heat. The condensor is large, but very close to the radiator. Evaporator size needs to be larger, but don't know that there is enough space. Heat shielding only goes so far with a big engine that close and the front radiator.