A/C vents, WH smell, serial #, & search

[wdk450]

Gang:
I have only posted on this forum once before, so forgive my newbieness.

We took delivery of our new 2008 3670 RL today from Ray's RV's in Fairfield, Ca. During the walkthrough we smelled a strong plastic burning smell we think was coming from the refrigerator roof vent. It was hard to locate outside as it was windy. Has this happened before? Should I worry?

The biggest other concern I had was the airflow from the air conditionig vents. It was strong from the 2 vents nearest the A/C in the kitchen, but noticibly weak at the next 2 vents above the rear chairs, weak everywhere else, and weakest of all in the bedroom. This makes me worry about sleeping on warm nights. The vents are such that you cannot restrict athe airflow to get more airflow at other vent locations. Is this normal operation for the A/C vents?

Our VIN ends in 11184. Is that our "number" or 1184?

I am pretty computer literate, but seem not to get focused results when I try to search these topics on the forum. I get some thread hits, but a lot more about towing and unrelated issues. Is there some secret to using the search function here?

Bill Knight
2008 Bighorn 3670RL
2004 Purple Dodge Ram 3500 Longbed Dually Cummins Diesel

 

[ChopperBill]

They ain't fixed that air problem yet? Time to roll out TimK's Tent In The Vent post again!

 

[wdk450]

Retired4Fun:
I found that thread in the search I did, saw that it was from 2 years ago and Jim from Heartland was a participant with the same problem in his rig. I thought this problem would have made its way back to Heartland and gotten fixed by now.

Bill Knight
Sacramento

 

[shaneandtammymoore]

a/c

I was also one of those people on that A/C problem 2+ years ago. I would be glad to share with you the things I did, not the dealer, to fix my problem. Feel free to send me a PM and I will give you my email and/or phone number.

 

[wdk450]

AC Vents

Gang:
I just did a websearch on "RV air conditioning Vents" and found a listing for what looks like the factory vents for about $7 each. There was also a listing for the same vent WITH A DAMPER for about $8. Here is the link:

http://www.rvwholesalers.com/catalog/product.php?productid=1465&cat=203&page=1

I started to order 8 of these, but in the checkout I was asked for my Tax ID number, so I thought along with their name they are resale only. I am going to call them, as I see they have new RV's for sale, so maybe they aren't retail only.

Bill Knight
Sacramento

 

[Ray LeTourneau]

Bill, it's sad to say, it sounds like this problem hasn't gone away. The link to the tent in the vent is your best and quickest solution. In addition to that modification, I used aluminum tape to direct the flow of air out of the vents in the last vents in the duct line. In other words, to keep the air flow from going past the vent and going to a dead end in the duct. The "tent in the vent" helps direct the air from the squirrel cage fan into the vents along side the a/c plenum. It's an easy fix and should take less than a half-hour. Replacing the vents with dampered vent is little or no help unless you have good flow in the first place. The only vent I ended up restricting was the bathroom vent.

 

[tmcran]

Will this fix work on the Sundance?

 

[jbeletti]

Hi Bill,

Welcome to the Heartland Owners Forum.

Your coach was produced 2 production years ago. Could be that the flashing has failed in the air box area of your AC.

I'll try to do this from memory... This is NOT a factory fix or factory endorsed. This is just an idea from one user to another

If you are handy, I suggest you get some foil flashing tape, a ladder, a phillips screwdriver and a knife.

1. Turn OFF the AC/Thermostat and/or the breaker for the AC
2. Using the point of the knife, carefully remove the 2 round white plastic screw covers on the large plastic cover for your AC at the ceiling
3. Remove the 2 screws under those covers.
4. Remove the AC filter cover and filter
5. Wash the filter good, squeeze out the water and let it air dry
6. Remove the 2 screws found under the filter
7. Remove and place aside, the entire white AC cover from the ceiling
8. Looking up into the AC, you will see two separate chambers. One is the air intake, where your filter was and the other side is the output chamber, where the openable chill grate was. There is usually a sheet metal plate that divides those two chambers. Check it to make sure it has not slid down. Often times, this is held in place with double-sided tape. If it has slid, or if it has a gap at all, put it back in place and seal it up well with the flashing tape.
9. Now, on the output side, look on each side and you will see the ducts where the chilled air goes from the chamber to each of these ducts and down the length of your coach. Look at the edges of those ducts and look at how well they are flashed. Using more flashing tape, reflash those areas to smooth them out as much as possible.
10. While you are up there, look at the squirrel cage fan if you can see it. See how it blows downward? Chilled air blows down and then has to find it's way out to those two ducts. This is where the Timk "tent-in-a-vent" modification comes into play. Here again, this is not a sanctioned mod. Each decides on his own to do it or not. What it does is ends up making the airflow to the ducts much more efficient. This mod is well detailed on the forum so I won't go into detail. It can be done inexpensively and quickly. Some use tape flashed cardboard, others use a tape flashed aluminum can and still others use sheetmetal. I made one with sheet metal in my 2005 Landmark and it increased the air flow tremendously.

As for the burning plastic smell, you really need to track this down as it could be dangerous.

Jim

1. A

 

[jbeletti]

Will this fix work on the Sundance?

The Timk "tent-in-a-vent" is more an "air-flow improvement modification" to the Dometic AC design, than it is a fix.

Open your AC up and take a look. My sense is that it would work for you if you feel your air flow from the AC vents could be stronger.

That all said, does this modification void any warranties (Heartland, Dometic...)? Does/can it cause other issues?

This is one of those "use at your own risk" sorts of things. I don't mean to scare anyone. I have done the mod and was happy with the results. To my knowledge, my 2005 LM is still in use by it's second owner.

Just be aware that you are "on your own" when you do any modification.

Jim

 

[wdk450]

Tent in a Vent / Fluidics

First of all, it is hard to argue with success. I will try the mods Jim and others have suggested, but I don't know when I can see if I have been successful as the rig is in indoor storage without AC power.

It seems to me that a pressurized air duct system is analgous to a lawn sprinkler system; being that air and water are both fluids (my son is an aerospace engineer). Both have a supply of pressure (blower and domestic water supply); both use sealed piping (pipes/ducts) to deliver the fluid to the emitters (sprinkler heads/cooling vents). If there is a low pressure source, obstructions in the fluid path, leaks from the fluid path, insufficient sizing of the fluid paths, or restrictive emitters, there will be low flow at the emitters. Vents before the end of a duct should be no problem as long as the duct is completely sealed. Having a variable restriction (i.e. dampers) at the vents should allow you to "tune" the system (and compensate for the pressure losses in long duct runs) just as sprinkler heads are adjustable to compensate for pressure lossed due to long piping runs (a form of restriction).
In the hospital where I worked for 28 years, air supply ducts were checked regularly by an environmental inspector with attachable air flow measuring hoods. Based on these readings dampers were adjusted to even out air flow.
Today I found the vents with the dampers at my local trailer supply. I guess I will have to pay for them. I think that if AC vent airflows is a known problem for Heartland this should be checked at the factory during quality assurance testing.

Bill Knight
Sacramento

 

[SmokeyBare]

What makes you think the duct work is a sealed system?

 

[leftyf]

but I don't know when I can see if I have been successful as the rig is in indoor storage without AC power.

Then don't do the work until you can test the outcome.

Today I found the vents with the dampers at my local trailer supply. I guess I will have to pay for them.

Great let us know how it works out.

 

[jbeletti]

Today I found the vents with the dampers at my local trailer supply. I guess I will have to pay for them. I think that if AC vent airflows is a known problem for Heartland this should be checked at the factory during quality assurance testing.

I know little about airflow dynamics. So I am not sure that closing off some vents increases airflow to others. Maybe it does. Someone on the forum is an HVAC specialist and my be able to weigh in.

As for "known aiflow problems" - I'd say in 20,000 coaches, there may be a miniscule amount with true issues with the ducts (i.e. crushed etc.).

I think what many of us agree on is that the airbox design of the Dometic AC may be the weak link. Here again, I'd love to hear some input from HVAC specialists that have studied their RV AC unit. Maybe they have even better modification/improvement suggestions for the DIY'er.

Jim

 

[wdk450]

I was also one of those people on that A/C problem 2+ years ago. I would be glad to share with you the things I did, not the dealer, to fix my problem. Feel free to send me a PM and I will give you my email and/or phone number.

Shane:
I would be interested in those AC fixes, though as I have just taken delivery of my coach, I am of the bent that Heartland should be fixing this.

Thanks for your help.

Bill Knight
Sacramento

 

[jbeletti]

Shane:
I would be interested in those AC fixes, though as I have just taken delivery of my coach, I am of the bent that Heartland should be fixing this.

Thanks for your help.

Bill Knight
Sacramento

Bill,

If you are under warranty and their is truly an error/defect in the construction of your coach that precludes AC operation, you need to get this into your dealer. Heartland would love to fix an error we made on the line.

Please call our customer service department on Monday to have a chat about this. 877-262-8032. Keep the forum in the loop as to your progress on this.

Thanks,

Jim

 

[Bobby A]

Now you guys got me worried and I haven't even taken delivery of my unit yet. Jim, Please tell me the factory is aware of this issue and is making a change/fix.

 

[jbeletti]

Stop worrying Bobby.

Jim