Air conditioners, the vent ducts are not working!!!

[Tanman]

Our voltage is a 2013 3200 Epic series with All weather package. It was shipped from the factory in the first week of June 2012. Maybe the All weather package makes a difference. I dont know.

[Infinityrver]

Originally Posted by Tanman

Our voltage is a 2013 3200 Epic series with All weather package. It was shipped from the factory in the first week of June 2012. Maybe the All weather package makes a difference. I dont know.

Thank you. I appreciate the information.

My coach was built in July 2011. They had just started making the Infinity several months earlier. Dutchmen did the cheap thing "styrafoam board" and found that it didn't work efficiently. I Cannot change what "STUPID" did.

Later, from complaints I'm sure, Dutchmen decided to go with "duct board" as you have proved.

Dutchmen CEO's are IDIOTS.

When I go to purchase another coach...........I'll have to pull down one of the air conditioning vents. "Once bitten twice shy".

[GOLDENYEARS]

Okay guys and gals out there having trouble with your cooling your rigs properly with the air conditioner in the kitchen. especially the infinity 3750FL. When you get a chance check and make certain there is air flow coming out of the 6 round adjustable vents that came with your rig and not sucking air back in. You owe it to yourself this summer. I am taking my rig in on the 14th of this month to have it looked at.

[72mach]

I do have air flow however I found something interesting and I don't know how to check it out. Recently I was replacing all of my 'puck' lights with LED panels to eliminate some of the heat. When I was doing it in the bedroom (3750) I was removing the 4 larger bulbs in the ceiling and lo and behold cold air was pouring out the light holes. My guess is that the ducting isn't sealed correctly as there shouldn't have been any (or little) air coming out of the holes for the recessed lights. I really have no idea on how to check the ducting unless there is a way to pull the ceiling off and get to the ducting. I do have air flow all the way to the front although is negligible but the flow coming out of the light holes would make a huge difference if the ducting was sealed properly.

[GOLDENYEARS]

Originally Posted by 72mach

I do have air flow however I found something interesting and I don't know how to check it out. Recently I was replacing all of my 'puck' lights with LED panels to eliminate some of the heat. When I was doing it in the bedroom (3750) I was removing the 4 larger bulbs in the ceiling and lo and behold cold air was pouring out the light holes. My guess is that the ducting isn't sealed correctly as there shouldn't have been any (or little) air coming out of the holes for the recessed lights. I really have no idea on how to check the ducting unless there is a way to pull the ceiling off and get to the ducting. I do have air flow all the way to the front although is negligible but the flow coming out of the light holes would make a huge difference if the ducting was sealed properly.

I am thinking about getting a small inspection camera from harbor freight this has a small flexible camera on it with the screen attached I believe. I think another name for it is a "bore scope"

check this out: Inspection Camera - Save on this Digital Inspection Camera. they are 85.00 not cheap, but not expensive either. May help you find your problem

By the way, is your rig still under warrenty? Even if it is not I would check with Dutchmen or your store where you bought the rig from. someone did not seal something properly. good luck.

[72mach]

Thanks for the reply, yes the trailer is still under warrenty. It was a end of year 2012 unit built in in late 2011 but I purchased it in 03/2013 so the warrenty should start from that date. I cannot hit the dealer where I bought it as they are 400 miles away and have to deal with CW here in Vegas.

85 dollars isnt bad and perhaps I will check with Home Depot to see if they rent one in the tool crib.

[Infinityrver]

I haven't switched to LED's like 72mach but I feel his pain. I discovered the same issue in my living room (3850RL). I was replacing a bulb by the air intake and felt a considerable amount of air coming out of the light fixture. I am not convinced that this is just a leak. I believe it is flaw created by Dutchmen. In all their infinite wisdom.

This is nothing more then the Dutchmen engineering department (a monkey eating a banana) trying to save money in manufacturing.

Chances are the way that Dutchmen has adapted the air conditioner to the styrafoam is as good as their styrafoam duct work idea.

I'll be anxious to here what you see if you get a scope.

[kevinmiles]

Sometimes it is better to go with the flow (pardon the pun) - could you just make a vent out of the light fixture hole? (I am sort of kidding here, but you never know...)

[sundancer 87]

I too discovered a nice cool breeze blowing between the ceiling/roof space when I was changing out the halogen lamps.

I can however see silver ductwork connected to the ceiling outlets. I have removed the ceiling outlets in the bedroom and sure enough the ductwork is there and attached.

My thought is perhaps there is a small amount of air allowed to move through that space. In your residence air is moved in those spaces for ventilation. We don't have gable ends or soffits or anyway to vent that area so I feel it might be something necessary.

If I'm in the desert heat and I lose a little cooling in the room to help cool that air space to keep the desert heat from penetrating my living space I don't think it's a bad thing. We do need to keep the insides cool so if there's a little comprmise to do that I'm fine with it.

[GOLDENYEARS]

got the borescope will post pictures when i get the rig back.

[Infinityrver]

Originally Posted by sundancer 87

I too discovered a nice cool breeze blowing between the ceiling/roof space when I was changing out the halogen lamps.

I can however see silver ductwork connected to the ceiling outlets. I have removed the ceiling outlets in the bedroom and sure enough the ductwork is there and attached.

My thought is perhaps there is a small amount of air allowed to move through that space. In your residence air is moved in those spaces for ventilation. We don't have gable ends or soffits or anyway to vent that area so I feel it might be something necessary.

If I'm in the desert heat and I lose a little cooling in the room to help cool that air space to keep the desert heat from penetrating my living space I don't think it's a bad thing. We do need to keep the insides cool so if there's a little comprmise to do that I'm fine with it.

You are entitled to your opinion. You may compromise as much as you want. I do not share the same opinion.

I've had three other 5th wheels before this unit. I have never had extreme cool air coming out my ceiling lights, ever.

I will be checking the next one that I purchase. Dutchmen leaves a lot to be desired with their duct work.

Just my opinion!

[Infinityrver]

Originally Posted by GOLDENYEARS

got the borescope will post pictures when i get the rig back.

Cool!

[knesdad]

Play nice people... Thank you.

Dave.

[Sinecure]

Has anyone noticed on a hot, humid day that the center of your living/kitchen area has condensation forming on the ceiling? I noticed this the other day and now I'm curious if I could cut out the ceiling and install a panel similar to the one in the bedroom. Then on hot days I could open the louvre and have all of the cold air dumped into the room. At night when temps dropped a little I could close the vent to have the air distributed throughout the rv.

[GOLDENYEARS]

do you have one or two air units?

[Sinecure]

I have 2 units, one in the front bedroom and one in the main living area. I have considered adding one to the garage but don't see a need if we could only take full advantage of the two I already have.

[Jrb5678]

I have owned two other coaches with ducted 15k AC systems. Both were used in AZ during many years of "very hot" summer fun (115 deg +). Both coaches cooled perfectly and after a day you could freeze meat inside. I used my 2013 Voltage 3950 for the first time over the 4th of July holiday. The main 15k unit just flat out did not work. The main issue is lack of air flow. The design of any forced air system is based on the size of the space it is being required to condition. These systems are a balanced system based on required specification for air flow, input to output, to properly "pressurize" the system.

Both my other coaches had big airflow and actually whistled at times. Most of my output ducts in my new 3950 have little or no air at all coming out. How could this be? Well having worked in electro-mechanical design for over 25 years it always points to one thing...poor design.

After doing some basic discovery about the system, then consulting with Dometic, the AC system manufacture, I have come to the conclusion that the main issue with my new 3950 is the two ducted return vents. My other coaches did not have this feature. The return was located directly under the unit at the base and had an unobstructed opening of about 14"X14". That equals about 196 sq. inches of return area.

After removing both vent covers I discovered that they were ducted returns which in itself is not the issue. The issue I discovered was that the duct sizing is way too small. I measured them and found them both to measure 1.5" x 11". That equals 16.5 sq. inches each or 33 sq inches total...TOTAL!!! This is the problem. That makes the return air volume almost 6 times smaller than my last coaches. That means my new new 3950 15k AC unit itself is actually moving the all the air it can get through those two small holes. Also add in the restriction of the black mesh screen filter on each vent cover and that equals very little air coming into the AC unit.

I plan to address this directly with Dutchmen only after I have diagramed the design, confirmed specifications with Dometic and measured the actual airflow into the unit. However, I am very confident that my conclusions are correct. This is really basic science.

My hope is Dutchmen is a good company and will take measures to correct this. I have already designed a couple of options to fix the problem. I look forward to comments.

[sundancer 87]

I'm thinking about adding another return air opening to my 3800. It's cool in Oklahoma's 95 degree heat but I know from experience it wouldn't cut the Arizona desert heat.

Let's hope you come up with a good idea to share so we can get these things making ice cubes!

[sundancer 87]

Just for giggle and grins I pulled both return air ducts down. Before I did that I measured the air flow out of one outlet (four open in the kitchen), and measured 4.5 km/h of wind speed. That's roughly 2.8 mph.

After pulling the returns the wind speed increased almost double, to 8.0 or 5mph.

I had no doubt you knew what you were talking about and applaud your input in this matter.

Besides increasing wind speed I notice cool air towards the floor whereas before I couldn't really feel the cool air on my feet.

You're on to something good with your observations.

As I sit here typing this I notice the rig getting cooler so I know I'm going to punch in another return air duct, maybe two.

[Infinityrver]

jrb5678,

Thank you, for your professional word on this cooling issue. I certainly appreciate your being able to characterize the issue with numbers/measurements.

Have you happened to pull your ceiling lights down while your air is on? This past weekend I pulled my lights down (around the air conditioner) just to get more air pushing. That's just plain weird!

We're installing a self contained ceiling unit in our bedroom. If need be we will do the same in the living room.

Hopefully, Dutchmen will understand your numbers.

I'll keep my fingers crossed .