Reconfiguring AC Outside Ductwork

[PaulaBarry]

We recently bought a 28 year old 24 x 56 doublewide in Florida.
Your book is our bible, but we can't find enough on this topic.

Currently, heat is provided by original electric furnace located near center of doublewide.
Currently, AC is provided by exterior package unit located near rear center of doublewide, with a recently blown out compressor.

Currently, 10" crossover duct is located outside under original furnace, near center of doublewide.
Currently, AC supply is 20 foot 12" duct, connected by Y to two 12 foot 10" ducts, each connected to underfloor ducts at tail end of doublewide.

We have bought a Goodman packaged unit heat pump, 4 ton, 15 seer with a 15 watt heat strip and plan to remove the original furnace. We plan to replace all existing outside ductwork.

QUESTION 1: When replacing existing ductwork, should we:

A) remove crossover duct and connect 10" supply ducts where crossover duct was (near center of doublewide)

B) remove crossover duct and connect 10" supply ducts where current AC ductwork is connected (near tail end of doublewide

C) none of the above

QUESTION 2: We bought a heavier unit (4 ton instead of 3.5 ton) because we plan to connect a third supply duct to an insulated 12 x 20 Baker room located outside the front door on the hitch end of the doublewide. We would like to be able to shut it off when we are not using it.

A) How should we configure the new supply ductwork (Y location, duct size, register size, shutoff location)

B) Current return register is located near rear wall (near AC unit), almost directly opposite front door. Will frequently leaving front door open provide adequate return flow or should we 1) install an additional return duct outside or 2) install a register through interior wall next to front door?

We have a licensed serviceman doing a changeout installation to satisfy warranty restrictions, energy savings tax credit restrictions and and to avoid us having to move heavy units (we are avid DIY's, but senior citizens). Thank you for your help.

[Robert]

Hi,

Pay the hvac tech a little extra for consult and advice or let him do it all together. You can cause many a headache when trying to do duct work on a manufactured home. Because of that, I never touch these type questions with me not being there.

For the money/investment spent, it can and often does go for naught because of DIY on the duct part.

Manufactured homes are just not duct friendly and should have an experienced eye in person to advise or do the job.


Sorry I cannot help more, but it is for the good of your unit and system and your comfort.


Take care and best wishes,
Robert