Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
Old 08-26-2015, 10:39 AM   #21
Senior Member
 
Join Date: Jun 2015
Location: Payson, AZ
Posts: 3,862
to oldtool2 - thank you! i'm amazed how I missed this. as you said the ones for the a/c are fully adjustable. the ones for the heater are not. how did I miss this? it looks real simple to get some adjustable ones (they do exist) and replace the non adjustable heater vents. I have lived in the house for 35 years and am still learning things about it. the rv is no different, i am learning new things everyday!
CHICKDOE is online now   Reply With Quote
Old 08-26-2015, 12:41 PM   #22
Senior Member
 
Join Date: May 2015
Posts: 925
Quote:
Originally Posted by CHICKDOE View Post
to oldtool2 - thank you! i'm amazed how I missed this. as you said the ones for the a/c are fully adjustable. the ones for the heater are not. how did I miss this? it looks real simple to get some adjustable ones (they do exist) and replace the non adjustable heater vents. I have lived in the house for 35 years and am still learning things about it. the rv is no different, i am learning new things everyday!
I want to caution you on one thing about the floor register. The furnace is designed with a sail switch that must make in order for the furnace to continue to run. You can redirect the air flow but do not block too much flow off. If you do the furnace will shut down. I think that is the reason they install fixed registers, so people don't close them down too much and cause a problem.

Jim
__________________
07 Dodge 1500 crew cab with 20" wheels, 08 Forest River Rockwood Signature Ultra-lite 8280SS
"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man."
George Bernard Shaw
oldtool2 is offline   Reply With Quote
Old 08-26-2015, 01:45 PM   #23
Senior Member
 
Join Date: Jun 2015
Location: Payson, AZ
Posts: 3,862
to oldtool2 - your advice is appreciated. the intent would be to limit air flow from a couple of registers nearest the furnace and redirect it to those further away. I don't think this should affect the sail switch but I will keep the registers that I replace until I am sure! thanks again for this insight!
CHICKDOE is online now   Reply With Quote
Old 08-26-2015, 02:14 PM   #24
Senior Member
 
Witch Doctor's Avatar
 
Join Date: Feb 2012
Location: Clarksville Va.
Posts: 10,422
Quote:
Originally Posted by CHICKDOE View Post
to oldtool2 - your advice is appreciated. the intent would be to limit air flow from a couple of registers nearest the furnace and redirect it to those further away. I don't think this should affect the sail switch but I will keep the registers that I replace until I am sure! thanks again for this insight!
I have done HVAC for a living when I was working. Closing a register really will not do what you want. The correct way to do it is to put a damper at the plenum or the wye branch, that is the only way to redirect air. People will say well air will back up, trust me it will not give you what you want, it comes down to static pressure. As far as Rd. registers for walls. I have not seen any with a damper that would fit in a 2" wall. I have looked at CW, HD, Lowes and hart and cooley the biggest manufacture. You can by a sleeve with a damper in it that you would put at the plieum after you remove the duct, then you can balance the air flow in the unit without having a high limit problem or a sail switch problem. It dosn't take much air flow to operate a sail switch, your problem will come from the limit first. I hope this helps and sorry for such a long answer and post...
__________________
Coachmen M/H
Concord
2018 / 300 DSC

Witch Doctor is offline   Reply With Quote
Old 08-26-2015, 05:15 PM   #25
Mod free 5er
 
Join Date: Mar 2008
Location: Concord, NC
Posts: 24,702
Quote:
Originally Posted by oldtool2 View Post
I want to caution you on one thing about the floor register. The furnace is designed with a sail switch that must make in order for the furnace to continue to run. You can redirect the air flow but do not block too much flow off. If you do the furnace will shut down. I think that is the reason they install fixed registers, so people don't close them down too much and cause a problem.

Jim
Don't think this is correct, there are 2 different fans, the air flow for the registers is not the same one as for the sail switch.
OldCoot is offline   Reply With Quote
Old 08-27-2015, 05:50 AM   #26
Senior Member
 
Witch Doctor's Avatar
 
Join Date: Feb 2012
Location: Clarksville Va.
Posts: 10,422
Quote:
Originally Posted by OldCoot View Post
Don't think this is correct, there are 2 different fans, the air flow for the registers is not the same one as for the sail switch.
This is not true there is one doubled shafted motor. It all has to do with the static pressure. That will slow your fan down. It is never wise to close any register off, but you can balance the system with dampers. That is the correct way to accomplish this...... You also have a double shafted motor in your A/C that supplies air over your Evap coil and also puts air through your Condenser coil.http://www.amazon.com/Suburban-23310...e+parts+motors....
__________________
Coachmen M/H
Concord
2018 / 300 DSC

Witch Doctor is offline   Reply With Quote
Old 08-27-2015, 07:58 AM   #27
Mod free 5er
 
Join Date: Mar 2008
Location: Concord, NC
Posts: 24,702
Quote:
Originally Posted by gljurczyk View Post
This is not true there is one doubled shafted motor. It all has to do with the static pressure. That will slow your fan down. It is never wise to close any register off, but you can balance the system with dampers. That is the correct way to accomplish this...... You also have a double shafted motor in your A/C that supplies air over your Evap coil and also puts air through your Condenser coil.Amazon.com: Suburban (233101) Furnace Motor: Automotive....
The fan doesn't know whether the register is partially closed or a damper is partially closed. In a direct drive blower with an induction motor restricting either the inlet or the outlet will decrease amperage, as both reduce the amount of work the blower wheel is able to do.
OldCoot is offline   Reply With Quote
Old 08-27-2015, 08:04 AM   #28
Phat Phrog Stunt Team
 
TURBS's Avatar
 
Join Date: Aug 2011
Location: Iowa
Posts: 34,507
And we're off!

TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "24 nights"
TURBS is offline   Reply With Quote
Old 08-27-2015, 08:45 AM   #29
Senior Member
 
Witch Doctor's Avatar
 
Join Date: Feb 2012
Location: Clarksville Va.
Posts: 10,422
Quote:
Originally Posted by OldCoot View Post
The fan doesn't know whether the register is partially closed or a damper is partially closed. In a direct drive blower with an induction motor restricting either the inlet or the outlet will decrease amperage, as both reduce the amount of work the blower wheel is able to do.
Sorry, but no. as you close down registers it increases the static pressure, If it was designed at lets say a 1/2" static to the fan curve by closing registers you are increasing the Static pressure which will slow down the speed on the curve. By putting adjustable dampers in at the plenum it will allow you to redirect the air flow to the area that is needed. but you would beable to keep the design pressure. By just closing a register it will not do what the op wants. If I put an CFM meter on the rest of the registers you would see what I'm talking about. The OP asked a question and I have given him the correct answer. It's up to him. I have designed 100's of system over 20 years......
__________________
Coachmen M/H
Concord
2018 / 300 DSC

Witch Doctor is offline   Reply With Quote
Old 08-27-2015, 09:10 AM   #30
Mod free 5er
 
Join Date: Mar 2008
Location: Concord, NC
Posts: 24,702
Evidently my furnace blower doesn't go by your rules because closing the register in the kitchen/lr or both increases the air flow outside the bedroom and the bathroom as well as the basement.
OldCoot is offline   Reply With Quote
Old 08-27-2015, 09:43 AM   #31
Senior Member
 
Witch Doctor's Avatar
 
Join Date: Feb 2012
Location: Clarksville Va.
Posts: 10,422
Quote:
Originally Posted by OldCoot View Post
Evidently my furnace blower doesn't go by your rules because closing the register in the kitchen/lr or both increases the air flow outside the bedroom and the bathroom as well as the basement.
Sorry, I forgot the "OLD COOT" way silly me.....:rofl black:
__________________
Coachmen M/H
Concord
2018 / 300 DSC

Witch Doctor is offline   Reply With Quote
Old 08-27-2015, 01:21 PM   #32
Senior Member
 
jtstromsburg's Avatar
 
Join Date: Jul 2011
Location: Stromsburg, Nebraska
Posts: 1,682
Something like this (I didn't read all 4 pages of posts so forgive me if it was already posted)

JR Products ACG25DPW-A Polar White Adjustable Ceiling Vent with 0.25" Collar https://www.amazon.com/dp/B0095TEFNA..._Et13vbXCYWC68
__________________
Joel and Teresa
2016 Sabre 34TBOK
2006 GMC 3500 CC LB DRW 4X4
jtstromsburg is offline   Reply With Quote
Old 08-28-2015, 10:17 AM   #33
Senior Member
 
Join Date: May 2015
Posts: 925
Quote:
Originally Posted by jtstromsburg View Post
Something like this (I didn't read all 4 pages of posts so forgive me if it was already posted)

JR Products ACG25DPW-A Polar White Adjustable Ceiling Vent with 0.25" Collar https://www.amazon.com/dp/B0095TEFNA..._Et13vbXCYWC68
Ceiling vents are covered, Working on floor vents now. I opened up a can of worms on them, LOL!

It is getting interesting though.

Jim
__________________
07 Dodge 1500 crew cab with 20" wheels, 08 Forest River Rockwood Signature Ultra-lite 8280SS
"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man."
George Bernard Shaw
oldtool2 is offline   Reply With Quote
Old 08-28-2015, 10:19 AM   #34
Phat Phrog Stunt Team
 
TURBS's Avatar
 
Join Date: Aug 2011
Location: Iowa
Posts: 34,507
Quote:
Originally Posted by oldtool2 View Post
Ceiling vents are covered, Working on floor vents now. I opened up a can of worms on them, LOL!

It is getting interesting though.

Jim
Be very careful closing off to many ducted a/c vents.
If your a/c doesn't flow enough air because vents are closed the a/c will freeze up.


TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "24 nights"
TURBS is offline   Reply With Quote
Old 08-28-2015, 10:24 AM   #35
Senior Member
 
Join Date: May 2015
Posts: 925
Quote:
Originally Posted by OldCoot View Post
Evidently my furnace blower doesn't go by your rules because closing the register in the kitchen/lr or both increases the air flow outside the bedroom and the bathroom as well as the basement.
Yes, closing off some registers can increase airflow out of others. You can also cause a problem with the furnace. Depending on the sensitivity of the switch you can cause it to short cycle and shutdown. You can get away with it up to a certain point before you run into a problem though. A lot depends on the size of the ductwork you have which we have no control over.

Jim
__________________
07 Dodge 1500 crew cab with 20" wheels, 08 Forest River Rockwood Signature Ultra-lite 8280SS
"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man."
George Bernard Shaw
oldtool2 is offline   Reply With Quote
Old 08-28-2015, 10:31 AM   #36
Senior Member
 
Join Date: May 2015
Posts: 925
Quote:
Originally Posted by gljurczyk View Post
I have done HVAC for a living when I was working. Closing a register really will not do what you want. The correct way to do it is to put a damper at the plenum or the wye branch, that is the only way to redirect air. People will say well air will back up, trust me it will not give you what you want, it comes down to static pressure. As far as Rd. registers for walls. I have not seen any with a damper that would fit in a 2" wall. I have looked at CW, HD, Lowes and hart and cooley the biggest manufacture. You can by a sleeve with a damper in it that you would put at the plieum after you remove the duct, then you can balance the air flow in the unit without having a high limit problem or a sail switch problem. It dosn't take much air flow to operate a sail switch, your problem will come from the limit first. I hope this helps and sorry for such a long answer and post...
What you are stating is correct. I thought about mentioning it but decided against. You would be talking about a lot of work to do this in a trailer, more than it's worth in my opinion.

If putting adjustable floor vents in does not correct the problem is some forced way would be to put a small fan at the top of the steps. This would allow for better air circulation throughout the trailer without tearing the floor up or the underside of the trailer to put in a damper.

In my opinion what you are suggesting is more work than it is worth.

Jim
__________________
07 Dodge 1500 crew cab with 20" wheels, 08 Forest River Rockwood Signature Ultra-lite 8280SS
"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man."
George Bernard Shaw
oldtool2 is offline   Reply With Quote
Old 08-28-2015, 10:37 AM   #37
Senior Member
 
Witch Doctor's Avatar
 
Join Date: Feb 2012
Location: Clarksville Va.
Posts: 10,422
Quote:
Originally Posted by oldtool2 View Post
Yes, closing off some registers can increase airflow out of others. You can also cause a problem with the furnace. Depending on the sensitivity of the switch you can cause it to short cycle and shutdown. You can get away with it up to a certain point before you run into a problem though. A lot depends on the size of the ductwork you have which we have no control over.

Jim
Remember that all your FAU duct is either 4" rd or 2" rd only. A 4" duct can only produce about 60 cfm. I think without looking it up in the speck sheet the FAU can only produce around 300 CFM. Once you start closing vents off, you will run the risk of limit problems. If you are having a real problem like at the other end of the TT. You would be better off moving the duct to the end of the plenum. But remember the plenum is a mixing chamber. Your heat exchanger has hot and cooler spots in them. That's why it's not always wise to do. But with these systems your hands are pretty well tied on what you can get by with.....
__________________
Coachmen M/H
Concord
2018 / 300 DSC

Witch Doctor is offline   Reply With Quote
Old 08-28-2015, 11:09 AM   #38
Senior Member
 
Join Date: May 2015
Posts: 925
Quote:
Originally Posted by gljurczyk View Post
But with these systems your hands are pretty well tied on what you can get by with.....
Agreed. Everything you have mentioned is true and in my house where I can go down to the basement where I have access to the ducts it would be fairly easy to correct. In fact I did 20 years ago when I moved here.

In a trailer it is a whole new ball game. Where you need to get is not accessible, at least not easily.

So now it is time to try and become creative.

Jim
__________________
07 Dodge 1500 crew cab with 20" wheels, 08 Forest River Rockwood Signature Ultra-lite 8280SS
"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man."
George Bernard Shaw
oldtool2 is offline   Reply With Quote
Old 10-13-2015, 08:30 AM   #39
Senior Member
 
PhoneDude 8289's Avatar
 
Join Date: Sep 2013
Location: Texas
Posts: 1,183
Click image for larger version

Name:	thumb_IMG_0634_1024.jpg
Views:	144
Size:	249.0 KB
ID:	91386
The picture above is the ducts that are to the Bathroom and the vent just outside the bathroom door. SO much air coming out of both caused both those areas to get so much hotter than the rear living area. I removed the collars coming out of the furnace and blocked 1/2 the outlet with sheet metal.


Click image for larger version

Name:	thumb_IMG_0635_1024.jpg
Views:	127
Size:	275.5 KB
ID:	91387

The image above is of the mod going to the ducts in the living area. I used 4" aluminum 90º ells from Home depot. Installed them on the collars coming off the furnace. I removed about 6' of the scrunched up flex duct the factory installed. The smooth radius of the aluminum ells and stretching out the flex allowed for much more air discharge at the floor registers in the rear living area. Getting more airflow from the living area vents than from the bath and hall vents now. A friend has a air velocity meter, going to try and borrow it from him to know how much air flow I have. I ran the furnace thru several cycles, sure seems even.

I did access the ductwork right at the furnace. The collars at the furnace are not screwed to the plenum, the way they are flanged they can be rotated to remove and replace. I removed the collars and installed a 2-1/2" x 6" piece of sheet metal on the inside of the plenum using sheet metal screws from the outside of the box blocking 1/2 of the 4" opening. I did this on the tap for the Bathroom and hall, really helped cut back the airflow to both those areas. I also removed the 4"X2" T that was feeding the vent in the basement.

By using the aluminum 90º ells and stretching out the flex duct allowed so much more airflow to the living area in the rear of the RV. Trying to move air through flex duct that is scrunched up and bent in a short radius creates a turbulence that restricts airflow.
__________________
__________________
Joe & Beverly
2014 Ram 2500 CTD, CC, SB
2014 8289WS lifted
PhoneDude 8289 is offline   Reply With Quote
Old 10-13-2015, 10:00 AM   #40
Left Coast
 
Join Date: Dec 2014
Location: vancouver,washington
Posts: 15,649
Send a message via Yahoo to bob caldwell
Quote:
Originally Posted by gljurczyk View Post
We have the same in our HIGH PRICE ROCKWOOD....
X2
bob caldwell is offline   Reply With Quote
Reply

Tags
furnace

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 11:31 AM.