New AC unit & evap coil, not cooling..

[teddy bear]

I think most mobine home indoor blowers are sized for 3 to 4 tons of air flow. If you are actually blowing 1200 cfm thru a two ton coil you'll have a real poor temp drop thru coil. Slowing down the air flow will improve the size of temp. drop and improve de-humidification. With only 8 degree drop, you're not getting hardly any de-humidification of the air passing thru the coil. What is your subcool reading? I'll wager it's very high! In our area, we seldom see AC units smaller than 2 1/2 tons on M.Homes. Never seen a 2 ton AC in M.Home!

Attaching a data graph that is representative of the output you should get from a 2 ton a/c.
I show the outside temp/^F dew point, the inside temp/%RH/^F dew point. Also the a/c supply ^F temp/^F dew points.
The air flow is is approx. 600 cfm.
Regards TB

[beenthere]

It's an electric furnace... What do you mean exactly about the 1200 CFM? I'm not really sure how that works, are you saying if the furnace blower is too big that it rushes past the coil too fast to cool or?

& yes, the old unit was two tons also.. Or possibly even 1.5

Yes, while 1200 CFM on a 3 ton unit might get you a 20 degree temp difference, 1200 CFM on a 2 ton unit would only be about 13 degrees.

[tedkidd]

I'm not sure what you mean about the 4 tons.... But, I'm pretty sure it's sealed up, I've looked and as I'm sure you know, it's just the long box, only has one trunk under the house.. I know it's a bad design but I have checked for leaks before, and there is no return, just an open area at the closet.

My comment was directed at a subsequently removed post by rage red suggesting 4 ton systems for mobile homes.

At every takeoff in your trunk there may be leakage at the seams. The duct ive seen looks like someone hacked two beer cans together at each register. This high pressure area may have significant leakage to outdoors, which means there is equal leakage of hot, humid air from outdoors at cracks and holes throughout the home to make up for the air leaving through your road barrier. Metallic tape applied to these seems can have significant impact, reducing loss of conditioned air and by default, depressurizing the home LESS which means less hot leaking IN.

If you take and share the pictures I suggested, you will get lots of comments about condition and whether this work is an opportunity.