Replace Dash HVAC with Old Air Hurricane System

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RHecht

New member
Jun 3, 2024
1
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Roswell, GA
All, my ‘74 GMC HVAC is toast. With that I intend to replace it with an Old Air Hurricane 3100 system. I know several coached have had this modification done, and I would love to learn from your experiences. With that please let me know how the installation was done, and if you have any pictures and what to do next time feel free to send them along.
 
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I'm in the same boat as the OP of this thread. My original climate control has never worked well. In fact it feels that if you operate it at any setting, in the winter it blows colder air than outside, while in the summer it is always warmer than outside air. I've resigned to have the whole system off and just drive with open windows any more.
I've been considering tearing out the old climate control monstrocity box and putting something like this in:
What is the benefit of the Hurricane system vs something like this?
 
I'll try to get my brother to post a build thread, believe he used that A/C unit, took the dash completely apart and built a new box for the A/C to fit in
 
I'm in the same boat as the OP of this thread. My original climate control has never worked well. In fact it feels that if you operate it at any setting, in the winter it blows colder air than outside, while in the summer it is always warmer than outside air. I've resigned to have the whole system off and just drive with open windows any more.
I've been considering tearing out the old climate control monstrocity box and putting something like this in:
What is the benefit of the Hurricane system vs something like this?
Buy cheap get cheap! My Old Air system works great.
 
I don't know if you have seen the old Co-Op video about this install.
AC install
Informative but far from what needs to be done. He isn't telling you that the dash has to be removed. You have to remove the original plenum so you can plum in the new vent feeds. That is a big job and not easy. The Old Air kit also supplies the compressor mount for an Oldsmobile engine.
 
Informative but far from what needs to be done. He isn't telling you that the dash has to be removed. You have to remove the original plenum so you can plum in the new vent feeds. That is a big job and not easy. The Old Air kit also supplies the compressor mount for an Oldsmobile engine.
I guess depending on the year of the coach. My 77 I did not have to remove the dash....just the complete box from the outside. I used the original ducts and plenum.
 

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I guess depending on the year of the coach. My 77 I did not have to remove the dash....just the complete box from the outside. I used the original ducts and plenum.
I at first just used the original plenum, mine being a 77. But I wasn't happy with air flow. I removed my dash and plumbed the air directly to the vents. 50% increase in air flow. That plenum was killing the flow. Nice installation N2hcky.
 
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I installed the Old Air Hurricane. Replaced the ducts and routed them as direct as I could. TBH I'm not thrilled with the results. It works just well enough to make the hot days tolerable, but it doesn't blow as hard as I'd have guessed, and it's very loud. To be fair, part of the problem is the vent locations on the dash— there's really no way to duct to them without killing the airflow.
On a positive note, I had to send the billet controls back because I accidentally ordered the wrong ones, and they were very helpful, and did the exchanged for free. Instructions were thorough and easy to follow.
 
This past Spring, right before a trip to Mineola, TX for the GMCMI rally, I had a Vintage Air unit added under my dash. I didn't try to do this myself, opting to have my mechanic friend do it instead. He is a wiz with air conditioning and did a great job. Part of this project was to replace the A-6 compressor with a HD Sanden unit. While in there, Jim refurbished the factory AC box and sent the heater core out for e rebuild. The lines are teed into the existing hoses (all new fittings and hoses)

WE just got back yesterday from a 1300+ mile trip from Tucson up to Albuquerque, followed by a loop up in Northern New Mexico, and around to Window Rock, AZ and the Mogollon Rim, finally home through East Metro Phoenix and back home. For probably the first time ever, we were comfortable in the cab in near 100 degree weather. This was without running the Onan and the roof air.

The parts came from Applied GMC, Jim (the mechanic) fabricated all the coolant lines etc and handled the installation for me. NOT cheap, but worth it and maybe a little simpler than starting from scratch with the Old Air unit.


https://www.gmcrvparts.com/product-p/g11301vuya.htm (similar to this unit but without heat.)
 
I too am preparing to upgrade my air conditioning system. This will be early next season, I’ve got enough going on this season. Anyhow, I’ve got a new Sanden compressor and was looking at what to do with cooling box and cool air delivery to the vents. Sounds like there are different opinions on the new Old Air cool air box. My thought would be to refurbish the original box along with make recommended modifications to improve air flow. Is this a futile effort, or does it improve cool air flow enough?

Thanks,
Tom
76 Eleganza 2
 
I too am preparing to upgrade my air conditioning system. This will be early next season, I’ve got enough going on this season. Anyhow, I’ve got a new Sanden compressor and was looking at what to do with cooling box and cool air delivery to the vents. Sounds like there are different opinions on the new Old Air cool air box. My thought would be to refurbish the original box along with make recommended modifications to improve air flow. Is this a futile effort, or does it improve cool air flow enough?

Thanks,
Tom
76 Eleganza 2
76 eleganza? I would not utilize the existing air vents. No proven method to copy that makes it work.
 
This past Spring, right before a trip to Mineola, TX for the GMCMI rally, I had a Vintage Air unit added under my dash. I didn't try to do this myself, opting to have my mechanic friend do it instead. He is a wiz with air conditioning and did a great job. Part of this project was to replace the A-6 compressor with a HD Sanden unit. While in there, Jim refurbished the factory AC box and sent the heater core out for e rebuild. The lines are teed into the existing hoses (all new fittings and hoses)

WE just got back yesterday from a 1300+ mile trip from Tucson up to Albuquerque, followed by a loop up in Northern New Mexico, and around to Window Rock, AZ and the Mogollon Rim, finally home through East Metro Phoenix and back home. For probably the first time ever, we were comfortable in the cab in near 100 degree weather. This was without running the Onan and the roof air.

The parts came from Applied GMC, Jim (the mechanic) fabricated all the coolant lines etc and handled the installation for me. NOT cheap, but worth it and maybe a little simpler than starting from scratch with the Old Air unit.


https://www.gmcrvparts.com/product-p/g11301vuya.htm (similar to this unit but without heat.)
Do you have an image of that under dash AC installed?

Ed
 
76 eleganza? I would not utilize the existing air vents. No proven method to copy that makes it work.
Not understanding about the existing air vents. My air vent for my air conditioning looks similar to Carls photo except I have just 2 vents that cold air come out. The vents on the dash and side vents on the sides seem only have heat in winter come out of them. So are you meaning those vents?

Tom