AC - outside air vs inside air?
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
AC - outside air vs inside air?
I came across a post in my AC file for my 71 vert that suggests:
1. Disconnecting the vacuum actuators on the fresh air flapper and MaxAC door.
2. close and seal the fresh air door with silicone
3. remove the MaxAC door
4. plug vacuum lines
The recirculates inside air all the time and improves the AC performance.
Has anyone tried this? If so, what were the results?
1. Disconnecting the vacuum actuators on the fresh air flapper and MaxAC door.
2. close and seal the fresh air door with silicone
3. remove the MaxAC door
4. plug vacuum lines
The recirculates inside air all the time and improves the AC performance.
Has anyone tried this? If so, what were the results?
Drifting
Joined: Dec 2004
Posts: 1,345
Likes: 3
Originally Posted by lostpatrolman
Wouldnt good sealing new seals be just as effective?
Also why butcher the car needlessly? The AC should be able to freeze you out if it is properly charged and working right. It is very nearly the same system used in full sized Chevy station wagons!!
Racer
Joined: Apr 2005
Posts: 339
Likes: 1
From: San Diego CA
I pinned the fresh air door shut on my '71. You do lose the ability to get fresh air in the car, but I think it's worth it. If I need fresh air, I'll open a window!
The door's flap had a tear in it, and it's been discontinued, so I closed it off.
There's actually another thread running around titled "Interior still hot..." that I started a few weeks ago. I recommend checking it out. It's received a lot of great info.
The door's flap had a tear in it, and it's been discontinued, so I closed it off.
There's actually another thread running around titled "Interior still hot..." that I started a few weeks ago. I recommend checking it out. It's received a lot of great info.
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Lost Patrol and StickShift,
I've not been able to find a replacement rubber fresh air seal and mine's now 35 years old and deteriorated. I've read that even when new, air pressure at the cowl when at speed causes it to leak.
I have plenty of fresh air with the vert so I'm really not losing anything by just continually recirculating interior air.
I don't know that this modification is any more butchering than other performance related mods that we all have made.
I've not been able to find a replacement rubber fresh air seal and mine's now 35 years old and deteriorated. I've read that even when new, air pressure at the cowl when at speed causes it to leak.
I have plenty of fresh air with the vert so I'm really not losing anything by just continually recirculating interior air.
I don't know that this modification is any more butchering than other performance related mods that we all have made.
Racer
Joined: Jan 2003
Posts: 383
Likes: 0
From: Columbia SC
Originally Posted by flynhi
I came across a post in my AC file for my 71 vert that suggests:
1. Disconnecting the vacuum actuators on the fresh air flapper and MaxAC door.
2. close and seal the fresh air door with silicone
3. remove the MaxAC door
4. plug vacuum lines
The recirculates inside air all the time and improves the AC performance.
Has anyone tried this? If so, what were the results?
1. Disconnecting the vacuum actuators on the fresh air flapper and MaxAC door.
2. close and seal the fresh air door with silicone
3. remove the MaxAC door
4. plug vacuum lines
The recirculates inside air all the time and improves the AC performance.
Has anyone tried this? If so, what were the results?
Only 2 ways to prevent this. first is to allow fresh air into the evaporator and the second is to allow hot water thru the heater core (turn the heat on).
If you A/C is not running 100% then you might not run into this situation.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by flynhi
Lost Patrol and StickShift,
I've not been able to find a replacement rubber fresh air seal and mine's now 35 years old and deteriorated....
I've not been able to find a replacement rubber fresh air seal and mine's now 35 years old and deteriorated....
Last edited by markdtn; Aug 2, 2005 at 12:52 PM.
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
...my A/C does not work on Max..and my fan does not work on "high" speed....and I have disabled my heater...so I have no intention of fixing those items now...except the heat on pass side....getting real close..insulating exterior footwells...rarely need A/C..just run it to keep seals lubricated..
Happiness is (in my case) tops off,windows down, driving the thing...
But,for those who want to get tangled up in ventilation....
http://home.comcast.net/~chadwick.ro...entilation.htm
Happiness is (in my case) tops off,windows down, driving the thing...
But,for those who want to get tangled up in ventilation....
http://home.comcast.net/~chadwick.ro...entilation.htm
Last edited by rihwoods; Aug 2, 2005 at 01:25 PM.
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Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Pete67shark - good point, I have a freeze protection switch that disengages the compressor if the evaporator begins to freeze up.
Markdtn - I have ordered the Dr. Rebuild repair kit but it's for the interior air recirculation door at the passenger's feet. The problem I'm having is witth the rubber like flapper on the cowl fresh air opening. I cannot find a source for these.
Markdtn - I have ordered the Dr. Rebuild repair kit but it's for the interior air recirculation door at the passenger's feet. The problem I'm having is witth the rubber like flapper on the cowl fresh air opening. I cannot find a source for these.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by flynhi
Markdtn - I have ordered the Dr. Rebuild repair kit but it's for the interior air recirculation door at the passenger's feet. The problem I'm having is witth the rubber like flapper on the cowl fresh air opening. I cannot find a source for these.
Burning Brakes
Joined: Mar 1999
Posts: 1,047
Likes: 3
From: CA
Originally Posted by flynhi
I came across a post in my AC file for my 71 vert that suggests:
1. Disconnecting the vacuum actuators on the fresh air flapper and MaxAC door.
2. close and seal the fresh air door with silicone
3. remove the MaxAC door
4. plug vacuum lines
The recirculates inside air all the time and improves the AC performance.
Has anyone tried this? If so, what were the results?
1. Disconnecting the vacuum actuators on the fresh air flapper and MaxAC door.
2. close and seal the fresh air door with silicone
3. remove the MaxAC door
4. plug vacuum lines
The recirculates inside air all the time and improves the AC performance.
Has anyone tried this? If so, what were the results?
Racer
Joined: Apr 2005
Posts: 339
Likes: 1
From: San Diego CA
Originally Posted by PaulH
You need to fresh air to defrost or defog your windows. If you permanently seal off fresh incoming air if will be difficult in certain weather conditions such as rainy days or cold day when the windows are closed to keep your windshield clear. To me this is a safety issue and for this reason would no do it.
Instructor
Joined: Apr 2005
Posts: 101
Likes: 0
From: webster ny
Max Air
Regarding Max Air: I recently started using my Air Cond and I noticed when I go to Max Air nothing changes far as I can tell. Can someone tell me what should happen when you switch to Max Air from norm Air? Thanks,
Hef
79 L-82 with aux fan
Hef
79 L-82 with aux fan
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
I've seen foam blocks in a couple of the catalogs that plug holes in the frame below the firewall. Anyone know where air entering through these openings exits? Any chance it is getting into the air plenum?
BTW, I have now used about a half a roll of rope caulk filling cracks and holes in the AC ductwork.......
BTW, I have now used about a half a roll of rope caulk filling cracks and holes in the AC ductwork.......
Last edited by flynhi; Aug 3, 2005 at 05:56 PM.
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Hef,
The max air door at the passenger's right foot should open and the cowl outside air door should close.
Trace the vacuum lines and test the actuators with a MityVac to see if they are functional. If they are and they do not work when the selector is rotated, you have a vacuum problem. If other functions work, you have a rotten or deteriorated vacuum hose to one actuator or the other or both.
The max air door at the passenger's right foot should open and the cowl outside air door should close.
Trace the vacuum lines and test the actuators with a MityVac to see if they are functional. If they are and they do not work when the selector is rotated, you have a vacuum problem. If other functions work, you have a rotten or deteriorated vacuum hose to one actuator or the other or both.
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
There is a book called "Air Conditioning Strategies for the 63-82 Corvette". It is a great book and well worth having to make your Vette cool and comfortable and explain the pecularities of the the C3 A/C system; and it is a strange system compared to others.
The book is approx. $20.00, and after having bought and used it, I would do it again!
Send $19.95 to Prestige Publishing, P.O. Box 2786, Grapevine, TX 76099-2786 and they will ship the book to you postage paid. Or you can buy it from one of the vendors.
I used the suggestions in the book and made my '79 a comfortable car to ride in. Hope this helps.
Bernie
The book is approx. $20.00, and after having bought and used it, I would do it again!
Send $19.95 to Prestige Publishing, P.O. Box 2786, Grapevine, TX 76099-2786 and they will ship the book to you postage paid. Or you can buy it from one of the vendors.
I used the suggestions in the book and made my '79 a comfortable car to ride in. Hope this helps.
Bernie
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
After caulking holes and seams in the air plenum, caulking ducts and revising vacuum lines so that the fresh air flapper is always closed (recirculating inside air)
Test Drive Results: Supply air 6 degrees colder on 95 degree day.
Not bad for a $4 roll of caulk.
Test Drive Results: Supply air 6 degrees colder on 95 degree day.
Not bad for a $4 roll of caulk.
