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Air conditioning crossover

Posted: Sat Jun 13, 2009 5:55 am
by zibrarian
I have a double wide manufactured home in which one side of the house cools better than the other. I have had the crossover duct work changed out to regular metal duct work. It is all tight and secure. The crawl space under the house is very cool. This is the reason I had the duct work changed out--to make sure the crossover was secure. The back of the house has plenty of air coming from the vents but there is very little coming from the vents in the front of the house. The AC runs almost constantly in the summer. The power bill gets really pricey in the summer. HELP!

Re: Air conditioning crossover

Posted: Sat Jun 13, 2009 9:05 am
by David Oxhandler
It seems that you are air-conditioning the space under the home.   If it is cool under there the air is escaping under the home.  You replaced the crossover so it appears that it is not where the problem is.   You have good air flow on the back side of the home so you can assume that the problem is in the front side where your not getting sufficient flow.You need to start just past the cross over and follow the duct work under the home.  With a bit of luck you will be able to feel with your hand where the cold air is escaping.  If not you will need to start exposing the duct work... By opening the belly board  and inspecting the duct run, 'till you find the leak.  Once the problem is found and resolved be sure to repack the insulation into the floor and reseal the belly wrap.  You should  take precautions when opening the bottom and handling the insulation and use proper protectiveRolled fiberglass insulation has plenty of air space included in it. I like to use the highest R value, thickest, rolled, insulation I can fit into the space between the bottom of the floor joist and the floor decking, with our crushing it. Once the insulation is in place you can purchase rolled vapor barrier material called Bottom Board by MH repair people and install it from below, stapling it to the bottom of the floor joist so it supports the insulation. You can find bottom board products at The Mobile Home Parts Store For details about installing insulation and important safety tips see How to Install Fiberglass Insulation and Crawl Space Insulation, from the U.S. Dept of Energy.   If your looking for a book that covers all facets of manufactured home repair, you've found it in The Manual for Manufactured Home Repair & Upgrade David Oxhandler [email protected]

Re: Air conditioning crossover

Posted: Tue Jun 16, 2009 11:54 am
by Tony Wilson
After many years of doing manufactured home setup and repair, I still find cases where the crossover duct is not accurately centered under the furnace, The crossover connection must be directly centered under the furnace or it will not properly carry air to the other side. You can easily check this from inside thehome To do this TURN OFF ALL BREAKERS TO THE FURNACE AND AIRCONDITIONER! Disconnect and slide the squirrel cage blower fan assembly out of the furnace. With a flashlight, look down thru the furnace past the heating elements and you should see the crossover duct connection, again this connection should be directly under the furnace, if it is off to one side or the other it will greatly hamper the transfer of air depending on how far off it is.
Another tip on checking ductwork without tearing out bellyboard and insulation is to remove the floor registers, take the shade off of a lamp and stick the light bulb down into the duct, go to the next nearest register and use a ladies hand mirror and stick it down into the duct looking back toward the light bulb, do this all the way thru the home. You can usually see pretty quick if the duct is crushed, torn open, or obstructed in any way. I've found everything from wads of inslation to scrap pieces of metal, even clothes obstructing ducts.

Re: Air conditioning crossover

Posted: Wed Jul 06, 2011 1:41 pm
by bodidley
One side of my crossover pipe is down.Unfortunately both inspectors did not catch this when I purchased the home,and the home is in an unincorporated part of our town,which means NO CODES .The problem is getting to the side that is down.The crawl space under the front of the Manufactured home is around 2ft high.Everyone knows what needs to be done,but can't seem to get anyone to crawl under there.I am disabled with severe back and neck injuries or I would suit up and give it a try!Any suggestions?I am also concerned about any further repairs down the road!

Re: Air conditioning crossover

Posted: Wed Jul 06, 2011 6:22 pm
by David Oxhandler
You should not be expected to crawl under the home. See my response to your other post http://www.mobilehome.com/phorum5/read. ... #msg-82871

Re: Air conditioning crossover

Posted: Sat Jul 16, 2011 10:53 pm
by mikeeaz101
my a/c doesnt blow out the vents the same. the air blows out good in masterbr livingroom not so good and kitchen is next room blows ok . it blows ok on both sides of doublewide except the livingroom. thanks

Re: Air conditioning crossover

Posted: Sun Jul 17, 2011 8:18 am
by David Oxhandler
The volume of air going to each room could be a factor of the placement of the unit, an air return problem, or a blockage or hole in the ducts. Call a professional air contractor to make a determination.

Re: Air conditioning crossover

Posted: Fri Jun 29, 2018 8:20 am
by sdellinger13
Tony Wilson wrote: Tue Jun 16, 2009 11:54 am After many years of doing manufactured home setup and repair, I still find cases where the crossover duct is not accurately centered under the furnace, The crossover connection must be directly centered under the furnace or it will not properly carry air to the other side. You can easily check this from inside thehome To do this TURN OFF ALL BREAKERS TO THE FURNACE AND AIRCONDITIONER! Disconnect and slide the squirrel cage blower fan assembly out of the furnace. With a flashlight, look down thru the furnace past the heating elements and you should see the crossover duct connection, again this connection should be directly under the furnace, if it is off to one side or the other it will greatly hamper the transfer of air depending on how far off it is.
Another tip on checking ductwork without tearing out bellyboard and insulation is to remove the floor registers, take the shade off of a lamp and stick the light bulb down into the duct, go to the next nearest register and use a ladies hand mirror and stick it down into the duct looking back toward the light bulb, do this all the way thru the home. You can usually see pretty quick if the duct is crushed, torn open, or obstructed in any way. I've found everything from wads of inslation to scrap pieces of metal, even clothes obstructing ducts.
I need your help please!! The AC company that installed my unit had to fix the duct coming from my furnace it was not directly under it. Well the front half doesn't cool like it should. Can't get anyone to repair this issue.
Was told that it will do that with a double wide??? WHAT? I just don't believe that.