Mobile home a/c

plumber101

A couple of days age I replaced a condenser and a coil in a mobil home.

It was a 3.5 tn, 13 SEER, R-410a. My distributor said that they had a mobil home coil because a 13 SEER A-coil would not fit due to height restrictions.

The old coil was an A-coil and the new coil was a N-coil.

Couple days later I get the call that it will not cool below 75 deg. I went and hooked up gauges High 325 and I had a 13 sub cooling. Low was 108 and I had a 20 super heat. Amps were 13.5
Out Amdient was 85
Inside wet bulb was 70

So I thought low air flow. My rep said to just add more vents because of low air flow across the coil. In which I told my rep that it worked fine until the old compressor shelled so why add more vents. I have a 12x14 trunk and eleven 6" branchs to register that are 4x10

I talked to another tech who said that N-coils do not work in mobil homes and to replace it with an A-coil.

I can get a 13 SEER A-coil from a mobile home supply that will fit but,

My question is will a N-coil work or not work in a mobil home down flow.

The furnace is a 80% downflow

pipefitter636

What is the indoor dry bulb temp,and the delta-t accoss the evap.ESP and actual cfm reading?

G 71

Never worked on a mobile home, so not sure why those furnaces wouldn't work with an N-coil, but it does seem like there would be more resistance through that than an A coil. Static pressure reading and blower chart for the furnace would confirm the problem.

pipefitter636

Checked with our Arcoaire rep and he said that there should be no problems with the coil. He said that is what there are designed for. But our local Coleman dealer does have a shortened version of the a-coil for mobile homes.http://icpindexing.mqgroup.com/docum...8431520001.pdf

plumber101

Odd that you say Arcoaire since I am a Arcoaire dealer.

My rep last night said the same thing. This morning a whole different tune.

He said that any 3 tn or larger needs an A-coil. He also said that I could place a couple of 3/4" conduit on each side of the N-coil to raise it up and it should? work.

I'm putting in an A-coil thursday. Let ya all know later.

jvegas

Hey plumber101 how did you make out with that coil

supertek65

how could you have 20 degrees superheat and poor airflow?????????????????

if you had 0 superheat or 2 degrees sh i would agree

i assume it is a scroll?
charge it to 10 degrees evaporator superheat.

good luck getting an efficient evap coil for a mobile home, there is no room.
how big is this mobile home?????
usually they are 3 ton and even then the duct work is wayyyy too small!

oh well good luck

by the way check your split across the coil 75 indoor air your discharge air should be 57 or 58

frank