Cold air dumping down under house from area of furnace

[Betsy]

My mobile home is a 2001 Fleetwood singlewide. For heat I have a Coleman furnace in the hall that came with the home. For cool I have a separate air conditioner installed outside, it is the type that is compressor and air handler all in one. I knew I had a problem when a rat showed up in my duct. I trapped the rat and relocated it far, far away. Then I went investigating my ducts as best I could from inside the house. By removing the register grills I found several had gaping breaches in the seams of the metal boxes that are formed around each floor register and I could feel the insulation through them. I used the shiny silver repair tape and fixed all of them. Today was spent under the house looking for tears in the underbelly fabric. I found plenty of them and used the underbelly repair fabric (stickiest stuff I've ever encountered) and was feeling very good about myself until I found the last one. A huge tear just under the furnace and nice cold air conditioned air just pouring down from it. I knew I was way in over my head as soon as I saw it. All the insulation was down and wiring and other foreign looking items up in there. So I just used my repair fabric and sealed up the rips in the underbelly. Now I'm in the house and I've looked at my furnace and see that I will have to call someone to fix whatever is wrong. I'm wondering though, can the repair be made from inside the house? Like if the service man removes the furnace maybe he can patch things up from this side? Or will he have to do the work from under the house? Could someone tell me what they think is going on? I am so discouraged because after all this work, time, and money there is really nothing to stop it all from happening again. I know we're supposed to be sure pests can't get under our homes but it's just impossible. At least for me it is. I've done all I can to seal up but there are places that simply can not be sealed. Thanks.

[Robert]

Hi Betsy,

All underbelly must be sealed and if unable to reach areas, will need to call someone.


If you feel cold air, then you have an opening in the duct.


Would be cheaper and easier from underneath than to remove furnace.


Also, IF you have a gas furnace, with a self-contained and/or Packaged Unit outside, be sure you have close off dampers under the furnace and at the connection of supply duct to main home duct trunkline.



In the books & parts link in top blue toolbar, Mark sells spray adhesive that is great also for patching underbelly with new sections of under belly material.



Thanks,
Robert

[Betsy]

Hi Robert and thank you for your input. I did seal up the underbelly fabric there where the cold air was coming down from the vicinity of the (electric) furnace so at least that got done. And I believe I found and repaired all the other rips in the underbelly fabric too. I called the AC guy who installed the air conditioning unit and he confirmed just what you said - that the work would have to be done from underneath. He told me to go back in ten days and check for water accumulation, either on the ground or on the underbelly fabric and if there was none then the problem isn't all that big of a deal. According to him it isn't unusual to feel some cold air coming down from the ducts. I feel like I should invest as little as possible in this fix because as much as I love my home I can't help but feel like it's just temporary shelter for now. I mean, flimsy vinyl skirting and easily torn plastic sheeting being all that lies between my home and the elements, wildlife, and insects out there? That isn't a real home.

[Robert]

Hi,


It isn't unusual to feel the air, but it isn't correct when doing so. It should be repaired if at all possible.



The skirting can be changed or better secured and the bellywrap is good against those issues when sealed completely.


If repaired and maintained, can/will withstand as good as most any home and at a usually lower price tag.




Take care and best wishes,
Robert

[Betsy]

Thank you again Robert. I agree the duct should be fixed but no one wants to spend hours under the house as I did so if they have to they charge so much I can't afford them.

[Robert]

Hi Betsy,

You're very welcome, I understand how that is.


Just do best you can and what is best for you.



Take care and best wishes,
Robert