Author Topic: HVAC  (Read 7913 times)

Offline theaddictedchef

  • Newbie
  • Posts: 96
  • Newbie
HVAC
« on: February 19, 2013, 02:58:14 am »
As you can see by the time, my mind is running while I think about what to do next. 

I pulled the ducting out tonight and am going to tackle that this weekend.  Here is my question/idea - I am thinking about cutting my ducting and installing flexible hose (similar to what you might find in a drop ceiling only smaller diameter) from the rigid areas that mount to the dash to the air diverters (vents).  My thoughts are that it would be a little easier and easier to replace should anything go wrong.

I have been thinking about this after getting in there and finding the ducting a mess.  It has already been cut in a number of places and then duct taped to terminate the ends.  The duct tape from the PO was all deteriorated so I wouldn't be cutting anything that wasn't already cut. 

I am worried that it might rattle, erode and not be efficient thus creating a problem and having to do it all over again.  Another thought is the summers here get ultra hot.  Not uncommon for it to be in the 107-115 range in July and August.  Does this have an impact on flexible HVAC hose?  Is weather even a factor? 

I'm up for any input........
The Journey IS the Reward......

Offline theaddictedchef

  • Newbie
  • Posts: 96
  • Newbie
Re: HVAC
« Reply #1 on: February 19, 2013, 02:58:53 am »
One more picture
The Journey IS the Reward......

Offline bake74

  • Senior Member
  • ****
  • Posts: 5871
    • Build Thread
Re: HVAC
« Reply #2 on: February 19, 2013, 07:21:36 am »
     I am not a a/c guy at all, I will probably have a long learning curve when I get to that on my build.  I will say that I feel for you, the PO seems like they just screwed everything up on your poor truck.
     You should be pretty close to a expert when you get done though.
#1: The easiest and most obvious solution to any problem is 99% of the time correct.
#2: There is no such thing as impossible, it just takes longer.
  74 k10, 77k10    Tom

Offline Donut

  • Frequent Member
  • **
  • Posts: 402
Re: HVAC
« Reply #3 on: February 19, 2013, 07:30:21 pm »
Making your own can be done, but it may be quicker and cleaner if you can source one elsewhere.  I honestly don't know if the ducting is re-popped.
Junkyard or Craigslist are other options.

Making your own may not be as clean looking, and you'll be adding restriction as you turn your 90's.  Don't know if the flow would be adequate for you.
'73 Chevy K-20 ***SOLD***
350/tbh350/np205
My plow was half price if i took the truck with it.

'86 C-30 dually, 454/tbh400

Offline theaddictedchef

  • Newbie
  • Posts: 96
  • Newbie
Re: HVAC
« Reply #4 on: February 19, 2013, 08:18:16 pm »
Didn't think about the 90 degree deal, thanks.  Gonna try CL here in a bit - see what I can find. 

Thanks for the input.
The Journey IS the Reward......

Offline pholliday1

  • Junior Member
  • ***
  • Posts: 632
  • 1990 V3500 Crew Cab
Re: HVAC
« Reply #5 on: February 20, 2013, 08:36:06 am »
Just did mine, the pieces in your picture aren't to awful far off from stock. I think the confusion is that where the vent on the passenger side and the small square vent on the lower drivers side do have short pieces of flex vent attached to them and as you pull out the rigid pieces in your picture the flex vent stays attached to the dash diffusers. I bought some 1 side sticky foam strip about 3/4 inch wide to attach to where the rigid plastic attaches large rectangle diffusers. These trucks also have a big problem between the lower " heater box and where the defrost duct attaches there's always a big gap if you look real close. I took some silver heating duct tape and sealed it up and per BD'S recommendation I replaced my fan motor with one from 1994 c1500 for more flow. Depending on how right you want to get this, your at a point where given the po's "hackness" pulling the cluster, the radio,glove box, ash tray, fix once and for all, loose wires  re check grounds, straighten a probably jumbled wiring harness, zip tie and neaten things up. and really after that your factory duct work should be no problem.
VETERAN AND LIFETIME NRA MEMBER. WHAT DO YOU STAND FOR?
1991 V3500 CREWCAB SRW 454TBI GMC
1991 v3500 crewcab SRW 454tbi 480le 6" lift
1990 V3500 crewcab Dana 60 FF 14b 5:38 ratio 40 inch 11" lift
1989 v3500 crewcab 454TBI 5" lift

Offline theaddictedchef

  • Newbie
  • Posts: 96
  • Newbie
Re: HVAC
« Reply #6 on: February 21, 2013, 01:04:32 am »
Thank you for the replies. 

Yes, the PO hacked this up pretty good.  Glad to know that my rigid pieces are too bad.  I was at the hardware store today and saw a thing of dryer vent tubing - got me thinking that maybe that would work.  I have some aluminum/heat duct tape that is high quality stuff from an aerospace place my pops works at.  I am good with that and think it will come in handy as I get closer to putting this back together.  The pieces that go from the rigid ducting to the air diffusers are gone - completely.  I am trying to think about some aftermarket idea that will accomplish what I am aiming for without pulling out of a junkyard, having it go bad in a short time, and then back to tearing my dash apart. 

I am doing a ton of behind the dash work so I cover everything.  Thank you for the reminder to hit the grounds and make sure they are good. 

Any thoughts on the dryer vent idea?
The Journey IS the Reward......

Offline pholliday1

  • Junior Member
  • ***
  • Posts: 632
  • 1990 V3500 Crew Cab
Re: HVAC
« Reply #7 on: February 21, 2013, 07:51:36 am »
I think dryer vent is around 4"? and you might need around 2" vent, I really don't remember vent diameter. Any vent material should be fine but honestly from the diffusers to the rigid plastic isn't really that far maybe 8-10 inches? really need to find some one with their dash off and take a picture. Your vent really could stand a good cleaning then some "sticky tape weather stripping foam". Above the fan control screwed down from the top is where the upper rigid vent mounts and the bottom ties in under the steering wheel, making sure these pieces are secure and indexed in the right direction will go a long way in keeping all the parts "together".
VETERAN AND LIFETIME NRA MEMBER. WHAT DO YOU STAND FOR?
1991 V3500 CREWCAB SRW 454TBI GMC
1991 v3500 crewcab SRW 454tbi 480le 6" lift
1990 V3500 crewcab Dana 60 FF 14b 5:38 ratio 40 inch 11" lift
1989 v3500 crewcab 454TBI 5" lift

Offline theaddictedchef

  • Newbie
  • Posts: 96
  • Newbie
Re: HVAC
« Reply #8 on: February 21, 2013, 08:04:53 am »
Again, many thanks.  If I can't find someone with the dash apart, any ideas on where to find a shematic on the ducting/routing?  I've searched and haven't been able to find anything that is detailed enough to see what I need to do. 

The Journey IS the Reward......

Offline 81_Chevy

  • Frequent Member
  • **
  • Posts: 449
  • A Truck Is Built, Not Bought
Re: HVAC
« Reply #9 on: February 26, 2013, 03:12:59 pm »
when i did mine i went from a custom deluxe trim to silverado so i had to change the vents and everything,

i just went to my local junkyard and looked for a decent one with the vents and inner tubes. worked out really well. i just cleaned them out really well and then worked pretty good. oh and the peice of round tubing that goes to the very far passenger side vent, usually its not there most of the time. you could use that 2inch tubing for that.

lol on another note i used that 4inch tubing for a "redneck" version of a cold air induction system  ;D
81 Chevy K20 350 4" Rough Country lift ridin on 35's ; 2 12 inch Subwoofers w/ a custom interior

Eagle Scout - 2012 Proud to be one!

Offline Captkaos

  • OWNER and Administrator
  • Administrator
  • Senior Member
  • *****
  • Posts: 18454
    • http://www.73-87chevytrucks.com
Re: HVAC
« Reply #10 on: February 26, 2013, 04:23:29 pm »
I have all my duct work out of my 87 right now.  What do you want to know.  The stuff you pictured looks fine, and they were never actually 100% sealed from the factory.

you can see most of my stuff here:

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19167
Re: HVAC
« Reply #11 on: February 27, 2013, 05:26:22 pm »
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Jason S

  • Senior Member
  • ****
  • Posts: 1561
Re: HVAC
« Reply #12 on: February 27, 2013, 07:13:33 pm »
For the flexible duct on the drivers side, I have used the RV septic drain tubing.  It works okay, it isn't a perfect fit. As for durability, it has been in my '73 GMC since about 2005 and is still intact after the summer temps in SW Oklahoma, West Texas and Eastern New Mexico (i.e., 115 degrees).  As for the hard plastic parts, I pretty much agree with the other posts in that they look usable.   
1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

"1) Peace through strength; 2) Trust but verify; 3) Beware of evil in the modern world"