Electric Air Conditioning. Will it work?

[Jonny Hart]

The 993 air con was rubbish today.

Haha! Can you quantify 'rubbish'?

[BenC]

Haha! Can you quantify 'rubbish'?

I turned it off and opened the windows

[sfaddis]

I would love this kit for my 914-6 GT replica. To add AC with a six, you have to cut a big hole in the firewall for the compressor. This also limits how far the drivers seat goes back. I have a stock 3.2 in my car, so it already has a beefy alternator, plus I already converted all the lights to LED.

-Steve

[Jonny Hart]

Pretty hot here today, 28 C (82F) in the shade. Got the car out in the sun and baked it to 50 C inside which was quite toasty. The dash was too hot to touch - the temperature gauge placed on it actually broke.

Hit the A/C and went for a drive. It took 5 mins to bring the temperature down to 28 C and a further 5 mins to around 24 C which is quite pleasing. The temperature was maintained at around 24 with a cool breeze on face and feet.

I'm limited by the 75A alternator to around 25% compressor speed at the moment and there is no air recirculation. Am working on a way to recirculate the air which should make a big different to vent temperatures. At the moment we are cooling fresh air so always from ambient.

Very pleased with the results. It doesn't have the immediate punch of icy blast of my modern but for a lightweight system that uses next to no engine power it really has made the 911 a much more pleasant place to be on a hot day.

Steve, should work well in any mid or rear engined car with a small cabin - 914 will be ideal. We have a system going into a GT40 replica at the moment.

[R2D2]

Very good Jonny - will definitely be ordering one of those babies!

[sfaddis]

I will take one too when available.

[Jonny Hart]

Wow, it's proper hot isn't it! Getting on for 32 deg C. 53 C on the dash, 15 degree vent, 25 ambient cabin. 48 amps drawn by the compressor.

We're gonna need an uprated alternator for the SC but thr 3.2 is probably ok.

200 miles again today, despite a dodgy clutch. Windows and sunroof closed the whole way!

Edited July 19, 2016 by Jonny Hart

[Dr Rock]

Windows and sunroof closed the whole way!

You don't need a sunroof when you have A/C.....

[Jonny Hart]

It was quite a novelty to be on the motorway in the hot weather without the billowing racket from the open windows and sunroof!

I sat in a 993 with fully functional A/C today. It would describe the cooling as underwhelming.

[BenC]

I sat in a 993 with fully functional A/C today. It would describe the cooling as underwhelming.

That sounds about right!

[Northy]

Jonny you need to start taking deposits whilst the weather is blazing!

[GaryH]

You don't need a sunroof when you have A/C.....

The sunroof in a 911 is as much use as an ashtray on a motorbike

[EJH911]

Anyone else with a 964, 993 or IB with air con? How's it doing today?

I moved house yesterday and so did a run from old to new in my car. I'll sum up the A/C in 2 words; complete crap.

When the moths in my current account give way to funds, I'll be calling!

[Beaky]

The sunroof in a 911 is as much use as an ashtray on a motorbike

I though it was a chimney for smoking cigars...........................

[EJH911]

I though it was a chimney for smoking cigars...........................

I hear that's more how cabrio owners roll...

[David Gander]

Now now Gary, I rather like my sunroof...........handy for chucking out those empty beer cans and watching them roll down the road behind you! ( Not the same from the side window, just adds to the general clutter on the verges!)

Regards,

David.

[3164G50]

I'm impressed, I really like the idea of it being discreet and integrated into the existing ventilation. e-Mail sent 23Jul16 23:14.

Steve

[Jonny Hart]

Hi folks. Just catching up on stuff. We did a test at Ricardo last week on the electric system. Pleased with the results but could do with more air flow for a properly hot country. It was a mere 42 C in the chamber:

Here's me (on the right) with my right hand man, Trev. We borrowed an air con equipped 964 to test.

Here's a ramp test (20 to 40 deg C) and a soak test (pull down from 40C).

Full report is here. The 964 really wasn't very good.

http://www.classicretrofit.com/media/1074/classic-retrofit-electrocooler-prototype-test.pdf

[Roy M]

Going through the report is it worth considering a clock delete option (with vent and hose) to use the space for a recirc vent or does it need to be located differently?

[R2D2]

What about "knees" and "toes" Jonny?

Good work, no easy task to get this right.

[sladey]

Altogether now......

Heeaad and shoulders, Knees and toes

[Beaky]

Altogether now......

Heeaad and shoulders, Knees and toes

Stop it .................its killing me

[Jonny Hart]

Going through the report is it worth considering a clock delete option (with vent and hose) to use the space for a recirc vent or does it need to be located differently?

Most cars in recirculation pull the air from low down since it is always colder down there as the cool air falls. Better not have cheesy feet! We are considering the clock position for an extra face vent though.

And please, keep your knees and toes covered up.

[GaryH]

We are considering the clock position for an extra face vent though.

Do it. Easily the best placed vent location on the dash (for the driver at least).

Edited September 8, 2016 by GaryH

[Jonny Hart]

Hi Folks, a little update.

Our session in the bake oven really showed how important it is to have recirculation of air from the cabin to get the most from the A/C. Our cars do not have this option as standard and we have devised various reconfigurations of pipework in order to achieve it. Essentially you need to get air from the footwells into the back of the airbox and prevent air entering from the bonnet vent. We are trying to achieve this with a redesign of the standard airbox which will feature extra spigots and 'flaps' to control this new feature.

It is very time consuming making patterns but finally we have something that fits in the car. This is a remake of the standard part but with room for the A/C evaporator to fit inside. I am trying to make the lefthand and righthand drive parts the same - note this has a lefthand drain as I was trial fitting. You can see that I had to remove the steering column cover so a bit more work to do here. We shall get a mould made from this in GRP to start. Might even go to CF for the production version but we are a way off that yet.

You can see the right hand spigot with a pipe attached and here is the left hand one.

The next challenge is to get those pipes through the body work and into the footwells along with the existing heater pipes. Remember there are all the 'standard pipes' to go back in too! There isn't a lot of room so this requires a cunning plan...