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Topic: Dash A/C cooling ability (Read 1192 times) previous topic - next topic

Dash A/C cooling ability

I am about to retrofit my Dash A/C to R134a. It dosn't work right now, Does it or Did they have enough capacity to keep that area cool while driving  originally or is it necessary to run the generator and the roof A/C's to keep comfortable on my 91 GV.

Re: Dash A/C cooling ability

Reply #1 –
Stump,
Can't say about the original R12, but I retrofitted mine to R134 and when it works quite well.  Getting the proper charge is key.  I replaced the compressor and the dryer when I retrofitted.

Re: Dash A/C cooling ability

Reply #2 –
This is totally dependent on outside ambient temps and how sunny or cloudy it is. I find that sunny and 80F is the breaking point. Relative humidity is also relevant.

Re: Dash A/C cooling ability

Reply #3 –
X2 on Peter's answer.  Ours was converted by the PO, including a new compressor.  Sometimes it seems to work pretty well, other times not so good.  We don't worry about it, because we always carry a "backup" (generator plus 1 or 2 roof airs).

Re: Dash A/C cooling ability

Reply #4 –
Foretravel just converted our U225's Dash A/C and it works very good. It also worked quite well before.  As Peter said I think 80 is the breaking point for us too, that is when we turn on the roof A/C. Sometimes  a 24 inch fan going along with dash A/C ... for what ever reason if we don't want to turn the Generator on.  Last year, first week in August driving from TX to OR, once I was in Amarillo i had the dash A/C on low and sometimes not even on, driver side window half way open was enough for the most part.

Oh BTW we like it cold, our Home is set to 69 year around.

Re: Dash A/C cooling ability

Reply #5 –
This isn't very helpful to you, but as a datapoint ours can keep us comfortable until about 90F.  We have a brand new compressor and high condensor fan which I'm sure helps.  We're obviously R134 from the factory.

Re: Dash A/C cooling ability

Reply #6 –
Many have stated that outside temp. is a key factor, which it is however its also the direction you are traveling. When driving into the sun, those rays play a big part in how you feel. I also changed my compressor and converted to 134 and with few exceptions it does a great job. 

Re: Dash A/C cooling ability

Reply #7 –
Our experience is that the dash air conditioner does a reasonable job, but in general isn't really up to the task. That's consistent with other comments I've read and hear about 1990s Foretravel dash air design. Therefore, we use and enjoy the dash air when needed, and don't hesitate to run the generator and roof air when additional cooling is required. Our generator is generally under-exercised and so the additional use is a benefit.

Re: Dash A/C cooling ability

Reply #8 –
Thanks for the responses. I'll swap over the A/C to 134a as soon as I get it back from TN RV doing the windshields and fixing my boo boo.

Re: Dash A/C cooling ability

Reply #9 –
I strongly believe the dash A/C should always be in good working order.  I say this because in mild temperatures with rainy and humid weather, the dash A/C serves control the fogging of the front windshield when the roof A/C's are not needed.  I have a very slow leak in the system and to date no one has been able to locate it.  Still the refrigerrant level is always kept to spec.

Re: Dash A/C cooling ability

Reply #10 –
I forgot to mention I also have 3M Crystalline Automotive Films on the windshield & driver and passenger side windows. $800 .. I know expensive but blocks Sun rays all out. DW needs Sun protection, she is very white. So when it is 100 F outside, when you put your hand on our dash it is as cool as the inside temperature so it is very very good to have.  Crystalline Automotive Films - Clear automotive window film for cars, trucks...

Re: Dash A/C cooling ability

Reply #11 –
Stump,
Before you change out your system to R134a, you might check out RedTec, R12a which is a replacement for R12 and compatible with the oils used in R12--- saves a bunch of money and time.
You can buy R12a on line on eBay.  Your system normally requires about 6 lbs of R12, but will only need about 2 1/2 lbs of R12a

Re: Dash A/C cooling ability

Reply #12 –
Quote from: Peter & Beth –
I have a very slow leak in the system and to date no one has been able to locate it.

Peter, find a knowledgeable REFRIGERATION tech and get them to inject UV dye into your system. Do not go the the auto guys and get the canned dye. That has a tendency to stop up things.  The UV dye is installed with an injection tool (the kit is about $200 + dye) and used in refrigeration systems widely. It requires a UV light to reveal what's leaking. I have had good success using it in restoring older vehicles. You can even tell if the evaporator is leaking because eventually the dye will show up in the water from the condensate tube.

TOM

Re: Dash A/C cooling ability

Reply #13 –
I had A/C problems also and Byer's Int'l injected dye and it turned out to be the compressor seal. Would pull a vacuum and hold it but would leak the freon in no time. Bought new compressor and that solved the problem. Would have been money ahead if I would have done that to begin with as MOT and Byers Intll fixed it for a day until it leaked out the freon.

Re: Dash A/C cooling ability

Reply #14 –
I thought about the R-12a switch but am going to go ahead and retrofit to 134a New compressor is just under $200.00 and dryer and T/X valve about 75.00 . I have 30lb 134a refrigerant on hand here. I was licensed HVAC contractor for over 10yrs before making a mid life career change and still have all my tools, U/V light leak detector, recovery machine ,vacuum pump etc etc,

Re: Dash A/C cooling ability

Reply #15 –
Quote from: stump –
  I was licensed HVAC contractor for over 10yrs before making a mid life career change and still have all my tools, U/V light leak detector, recovery machine ,vacuum pump etc etc,

Never get rid of your tools or parts!

Every time I have ever disposed of things I thought I would never use again, I have needed them very shortly thereafter.    :headwall:

Must be a law about that somewhere...........  Murphy perhaps?


TOM

Re: Dash A/C cooling ability

Reply #16 –
Air flow is important especially when trying to cool a large area like in a coach.
When I replaced the dash air blower motor I discovered that the squirrel cage vains had lost a lot of their aerodynamic shape due to dry crusted dirt.
Cleaned each vain with a small screw driver.
Ended up with a smooth quiet and higher airflow blower.
JD.

Re: Dash A/C cooling ability

Reply #17 –
Stump.....on our '89 the PO said over the past 21 years he had repaired it twice and still didn't work to his satisfaction so he keep the compressor disassembled.  We just use the windows and if it's that hot the genny and roof air

Re: Dash A/C cooling ability

Reply #18 –
Well having the 88 and now the 280 BOTH improved when I installed a thermal curtain just behind the pilot & copilot chairs. Cools to about 90/90 (heat humidity ) then it's generator, fans and roof ac.. keeps it under 75  ;D

Works great, looks good.. The rod is mounted along the seam on the roof panel

Re: Dash A/C cooling ability

Reply #19 –
Quote from: fouroureye –
I installed a thermal curtain just behind the pilot & copilot chairs.

Great ideas never go out of style.  I did the same thing in our 1972 "Honeymoon Ride".  The curtain behind the seats helped to maximize the meagre output of the vintage under-dash A/C unit.  Ahhh...a blushing bride, a Chevy Van, gold shag carpet, and a BUD...LIFE WAS GOOD!