a/c ducting and insulation. Amazing!

[rick_debbie_gallant]

Okay where to start. Just bought one of them Black and Decker thermo leak scanner for checking for air leaks etc. What I found was this:

1: The duct work that goes to the bedroom; on the door side it appears that the duct goes all the way to the closed and ends there. That is about 6 feet or so for our valuable cold air to bank up and cause condensate. I plugged up my duct with material to see if there was any differenc in the air out put, and there was. Before the plug stuff the temp of the ceiling where the duct was running was 62 degrees. after the plug the ceiling was about the same as the rest of the ceiling without the duct work.

On the off door side it appears the duct is plugged just after the discharge grill. In other words the duct stops after the vent and does not continue to the closet.

When I can figure out how to draw I will get some diagrams together

and some pictures. BTW I have a carrier air conditioning unit.

 

[Ray LeTourneau]

Rick, I know quite a while ago there were folks that had blocked off the ducts right at the last vents in the runs. I used aluminum flashing tape to deflect all of the air flow out of the last vent opening. that way no air can flow past the last vent and just "bounce" around up there. That in addition to the tent in the vent has made my bedroom A/C unit a rarely used piece of equipment. An amazing improvement in airflow.

 

[JohnDar]

Okay where to start. Just bought one of them Black and Decker thermo leak scanner for checking for air leaks etc. What I found was this:

1: The duct work that goes to the bedroom; on the door side it appears that the duct goes all the way to the closed and ends there. That is about 6 feet or so for our valuable cold air to bank up and cause condensate. I plugged up my duct with material to see if there was any differenc in the air out put, and there was. Before the plug stuff the temp of the ceiling where the duct was running was 62 degrees. after the plug the ceiling was about the same as the rest of the ceiling without the duct work.

On the off door side it appears the duct is plugged just after the discharge grill. In other words the duct stops after the vent and does not continue to the closet.

When I can figure out how to draw I will get some diagrams together

and some pictures. BTW I have a carrier air conditioning unit.

You've got ducts on the ODS of the bedroom?? Somebody musta stole mine and patched up the holes. All we have up there are the two on the DS and the one in the bathroom. But I'll take a look at plugging that duct next week, just for grins. With the rear A/C and a small desk fan on the dresser, we can keep it pretty comfy in the bedroom during the blistering days of northern MI summer. So much so that the cats walk around with their fur coats on .

 

[rick_debbie_gallant]

You've got ducts on the ODS of the bedroom?? Somebody musta stole mine and patched up the holes. All we have up there are the two on the DS and the one in the bathroom. But I'll take a look at plugging that duct next week, just for grins. With the rear A/C and a small desk fan on the dresser, we can keep it pretty comfy in the bedroom during the blistering days of northern MI summer. So much so that the cats walk around with their fur coats on .

You sure you dont have an ods vent? Besides that you dont need no stinking a/c up where you play. I dont think the sun can get through the canopy of trees!!!

 

[JohnDar]

You sure you dont have an ods vent? Besides that you dont need no stinking a/c up where you play. I dont think the sun can get through the canopy of trees!!!

99.99% sure, since I just looked at some photos we took of the bedroom. Only thing I can see on the ODS side is the antenna crank. The single vent in the bathroom, if extended, would end up in the middle of the bedroom ceiling.

But since they redesigned (messed up IMHO) the 3670 bedroom layout after the 2009 model, maybe they changed the A/C ducting as well.

Don't knock the tree canopy. Cuts down the wind and the sun load on the rig. But we do use the A/C occasionally when the temps and humidity get up there. I've been to many places in the country, but northern MI is still one of the best.

 

[RollingHome]

I recall reading "somewhere" that HVAC air ducts should not end at the last diffuser. Air ducts are supposed to extend past the last diffuser as HL has done. That being said, how can it be argued blocking the vent off doesn’t provide better cooling ? Too many here have proved otherwise ??? I guess I’ll have to try it too.

Another beneficial reason for the ducts to extend into the closet is to allow an AC electrical circuit (power & T-Stat) to go from the BR fan/vent – replaced with a BR AC into the duct & into the closet, down/around to the panel etc. However, most of HL’s units roll out the door with the wiring already installed for the 2[SUP]nd[/SUP] BR AC. HL installs a 12/2 yellow romex (terminated in a J-box & brkr panel) a 4 wire flat T-Stat wire (in the wall near the closet) and a 7 conductor 22 AWG accessory cable (run with T-Stat wire. This can be verified by dropping the fan/vent trim (4 screws). Mine was there, but the knucklehead that installed the fan/vent cut the T-stat & accessory wire/s too short (1") for me to use !!! I had to pull a new wire L

 

[porthole]

I recall reading "somewhere" that HVAC air ducts should not end at the last diffuser. Air ducts are supposed to extend past the last diffuser as HL has done. That being said, how can it be argued blocking the vent off doesn’t provide better cooling ? Too many here have proved otherwise ???

Have heard the same thing more then once. But I believe it is a short run, 12" or less. Where are all the HVAC engineers??

 

[2psnapod2]

As a Heating and AC installer, I always left a little extra duct after the last run. I was always told that you needed a little to ensure proper airflow. But the duct in a RV being so small, might be a little different than larger duct.