DIY Home Improvement Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
We are using this unit a 2.5 ton 14 seer self contained unit to cool a 14 x 70 mobile home.

https://www.acdirect.com/complete-systems/self-contained-package-units/2-5-ton

We had an old unit from the 70s that was way past worn out. We left everyting the same and really thought this would cool well. But it does not.

We have a large living room and kitchen which has vaulted ceilings plus a hallway that is all open so it has to cool this large area.

We have a furnace and the ac hooks into the duct work for that under the mobile home. The new AC unit was for 14" flexible duct work but our old flex duct work was 12" so we bought a reducer.

The vents in the floor are small 4" x 10 vents.


Mobile home has a metal roof and metal siding. On a 95 degree day it heats up like an oven.

I am thinking about moving my self contained ac unit down a little outside closer to the main large space (the living room and kitchen,hallway above) and placing a wall vent in the living room wall with a return vent there as well. And using one large wall vent with the unit as close as possible to the mobile home wall.

My thoughts are the air has too far to go running above 12 ft under mobile to tap into furnace vents....then having to run through the heat vents to each small floor vent. THE AIR COMING OUT IS COOL....but there isn't much blowing power.

I thought of running the blower side into the living room window to see how it would cool with a 14" flexpipe just to test this theory on whether it would cool better as one big vent. then leaving all doors to the home open inside so cool each room.

Am I crazy? Is there something else that can be done here?
 

·
Registered
Joined
·
5,868 Posts
12” flex will only flow 480 CFM at .05” WC static pressure.
That’s barely enough for 1 ton of airflow. Let alone 2.5 tons.
Mobile homes are also notorious for duct falling apart underneath. I’d inspect all ductwork for leaks and damage.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #3
Hello,

The underneath of the mobile home is in great condition. The duct work is just fine. In the winter it heats up just great.

But what do you think I should do.

I thought one big vent in the living room with the blower as close as possible to the vent in the wall.

If I leave things the same what should I do?

Can I use a bigger piece of regular duct work instead of the flex pipe.

I am pretty sure thinking back the duct work is very wide so that is probably why the 12" was used. The biggest that would fit and tap into the duct work.

Would a regular piece of duct work make that big of difference? Thanks for the help.
 

·
Super Moderator
Joined
·
39,290 Posts
You should run the 14" duct the unit is suppose to have, instead of reducing it like you did.


May new package units for mobile homes, require a second return, or enlarging the current return.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #5
Okay. Will the 14 inch really make a big difference?


Also the flex duct work goes about 14 ft under the trailer and connects to the metal duct work for my furnace. It currently has a 12" starting collar connecting to the metal duct work but I don't think it is large enough to fit a 14" starting collar. I don't think it is that wide.


I have to measure but if it is not what should I do here? Is doing some type of reducer going to be a problem here with air flow?
 

·
Super Moderator
Joined
·
39,290 Posts
Changing the connector to 14" would be best. But you can use a 14x12 reducer.
 
1 - 6 of 6 Posts
Top