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Topic: Overhead air conditioner ducts.  (Read 708 times) previous topic - next topic

Overhead air conditioner ducts.

It seems to me that I do not get that much air out of the bedroom air vents. With both units on, it seems like most of the air comes out of the front vents.  If I open the vent on the return air assembly, there is plenty of air dumped into bedroom with no noticeable reduction in front air vents.  If I close all the forward vents and the vent on the return assembly there is more air coming out the rear vents, but not nearly what you would consider sufficient for the output of two blowers.  Any ideas?
Steve DeLange
2005 U320T 40'
Pearland, Texas

Re: Overhead air conditioner ducts.

Reply #1 –
Mine seems to act the same way. I'm curious what others might have to say.
2002 U320 40Ft  MC # 15759
Coach # 5995
Previous coaches
2002 U320 coach  #5941
1996 U270 coach #4808

Re: Overhead air conditioner ducts.

Reply #2 –
If we have a real hot day we turn both ACs on to the cool the coach.  All the while the rear AC has the down draft open pouring cool air down into the bath.

After the coach is cool we turn off the front AC and have a floor fan blow cool air from the bath into the salon.

Works for us.

Not needed in the SF Bay Area these days ;o)

best, paul
1999 U320 40' 1200 watts on roof. 12cf AC/DC Cold plate fridge/freezer. VMS 240 CL Honda Element

Re: Overhead air conditioner ducts.

Reply #3 –
Removed air conditioner return/down draft cover and examined ducts.  They were not clogged, but it appeared to me that the rear ducts were smaller.  Reassembled and closed everything but rear vents.  The air out of the rear vents was greater but I was still getting substantial air out of the closed vents.  I did find that I originally had the forward air on low and the rear air on high.  Putting both on high helped some. 

I think I need to open the downdraft/flood flow valve well before we go to bed so everything has cooled down sufficiently.
Steve DeLange
2005 U320T 40'
Pearland, Texas

Re: Overhead air conditioner ducts.

Reply #4 –
We try to cool down the bedroom before turning in by using roof air and a bedroom shelf fan. Later when the outside temps are low enough, we turn on our new window fan and turn off roof air to keep bedroom cool all night. We made a PVC bracket to position the 20" square fan. It was inexpensive at Walmart and initially used it on a living room window ledge until it was re-assigned to the bedroom where there is no window ledge. We modified bedroom drapes to open from side.

Re: Overhead air conditioner ducts.

Reply #5 –
I have been playing with the vents and fan speeds and I am beginning to get a grasp on the system.  When on the road, I need to really cool down the bedroom so I don't need a high airflow when we are sleeping.
Steve DeLange
2005 U320T 40'
Pearland, Texas

Re: Overhead air conditioner ducts.

Reply #6 –
When both units are running or front or rear the air is distributed front and rear the same.  So I can turn rear off at night and only the front unit will cool the entire coach. 
Dan & Shirley Stansel
2002 U295 4020 AGDS Build#6054
Towing Buick Enclave & M &  G Braking
Emerald Bay, Lake Palestine, Texas
MC# 16650

Re: Overhead air conditioner ducts.

Reply #7 –
Quote from: Dan J. Stansel –
When both units are running or front or rear the air is distributed front and rear the same.  So I can turn rear off at night and only the front unit will cool the entire coach.

Advantage to ducted air.  Rear a/c is not in the bedroom.

Factory sales man don shipe had me walk cm fore through a 1991 marquis after I left Foretravel at an FMCA ralily.  Privately. Three of us. Cm said it was really pretty.  I thought it was almost over his head. Too many changes. Probably would have had to fight everyone in east Texas. 1991. 

I really tried.  Shipe knew I was a true believer.

Our 97 is a variation on a 91 marquis.  Seriously.  Better chassis. Less interior
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Overhead air conditioner ducts.

Reply #8 –
Another problem with the bedroom is that after driving, all the engine heat is back there. I think I'm going to rig up a way to turn on the A/C condenser fan while parked. It sucks air in from the outside. This will help draw cool air in under the engine bay and cool off faster--in theory.
1998 U270 34'

Re: Overhead air conditioner ducts.

Reply #9 –
Quote from: krush –
Another problem with the bedroom is that after driving, all the engine heat is back there. I think I'm going to rig up a way to turn on the A/C condenser fan while parked. It sucks air in from the outside. This will help draw cool air in under the engine bay and cool off faster--in theory.

Built a lot of Foretravels with exhaust fans in the rear cover to pull heat out of the engine bay. 1980's

Plus a few fire suppression systems
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Overhead air conditioner ducts.

Reply #10 –
Quote from: Caflashbob –
Built a lot of Foretravels with exhaust fans in the rear cover to pull heat out of the engine bay. 1980's

Plus a few fire suppression systems

When driving, it's not a huge deal as massive amount of air is flowing over everything. It's when stopped!

Sucking heat out with fans, or blowing cool air in--it all does the same thing. I figured trying out the condensor fan is worth a shot and a quick test will take a few pieces of wire and a switch as the relays are right there on the forward wall of the engine compartment.
1998 U270 34'

Re: Overhead air conditioner ducts.

Reply #11 –
Quote from: krush –
When driving, it's not a huge deal as massive amount of air is flowing over everything. It's when stopped!

Sucking heat out with fans, or blowing cool air in--it all does the same thing. I figured trying out the condensor fan is worth a shot and a quick test will take a few pieces of wire and a switch as the relays are right there on the forward wall of the engine compartment.

You guys are making me remember long ago things.  Which is good as some still applies.

A couple of Hayden trans cooler fans installed in the rear hatch grille comes to mind.

Manual switch?  On dash.  Not sure on that.
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Overhead air conditioner ducts.

Reply #12 –
RE " So I can turn rear off at night and only the front unit will cool the entire coach"

Our rear roof air has a bedroom wall mounted thermistor plugged in that controls rear air cycling.

Front roof air uses living room Comfort Control built-in thermistor because nothing is plugged into the front air.

Each roof air has a small two-wire connector and if nothing is plugged into it, that roof air defaults to the Comfort Control.

Based upon the above description of how the roof air works, we made a simple modification, so the front roof air can be controlled by bedroom temperature, which keeps the bedroom at the desired temperature using the front roof air conditioner.

Or rear air can be controlled by Comfort Control along with front air, which keeps both front & rear working to keep the coach at desired living room temperature.  No more finding rear roof shut off because the bedroom is too cold when at the same time the front living area is too warm. To check this part out, unplug the rear 2-wire plug and see how both roof airs turn on & off based up on front Comfort Control built-in thermistor.

Re: Overhead air conditioner ducts.

Reply #13 –
Quote from: Barry & Cindy –
Based upon the above description of how the roof air works, we made a simple modification, so the front roof air can be controlled by bedroom temperature, which keeps the bedroom at the desired temperature using the front roof air conditioner.

Do you have an explanation of this modification. I was having this same problem when I was using the RV and your solution sounds great.
1998 U270 34'
 

Re: Overhead air conditioner ducts.

Reply #15 –
Thank you!
1998 U270 34'