Coleman Mobile Home Furnace

[Toddbrewster]

I have a customer with a Coleman mobile home furnace about 2,100sq ft. 3 ton a/c system complains about not enough cooling says thermostat is never satisfied at 75. The condenser is clean filters clean, charge looks fine, customer wants a larger a/c unit. I told them 3 tons should be enough but their blower is only 1 speed. I am quoting them an upgrade to a 3 speed fan rated up to 4 tons instead of a whole new a/c system, has anyone upgraded the blower on a mobile home like this and had good results?

[ottawaair]

Mobile homes suck, I've seen 3 tons in 1000 sq ft doublewides run nonstop to keep up. That one had a west facing slider door that I think was made from a magnifying glass lol. Anyway, I have no doubt that a 3 ton can't keep up, especially if home has a lot of sun exposure.

[catmanacman]

Is the coil clean as they might look clean but can be impacted

[ar_hvac_man]

3 tons is way too small for a 2100 sq ft mobile home.

[uniservice]

Here 3 ton will do 1800 sq. ft. Our average summer temps are in the lower 60s, and upper 70s with 100% humidity. We seldom use A/C, mostly HPs. Have done add on coils and installed systems on existing MH furnaces. Usually change blower motors to 3 spd. 1/3 or 1/2 horsepower motors. Because of duct restrictions, it's a bear to get proper performance from the furnaces in "Wobbly Boxes." Used to do the wet finger test for years, but have had to get a little more sophisticated, since the guvment got involved in federal HP programs.

[Toddbrewster]

Yes the coils are clean, I just washed the condenser, and the evap is spotless. I could go to a 4 ton system but will still have to upgrade the blower, and that is the largest blower available for that furnace. I am sure the single speed one they have is not moving enough air, so I thought I would start there and if they still are not happy I can go to a 4 ton system. When I was at the home it did not feel to bad to me and seemed to be satisfying the stat.

[hewitt]

the system is to small.

[MicahWes]

What are the operating parameters of the system? Superheat/Subcool? Is the evap being fed with enough refrigerant?

[mh heating]

The home must be an older model due to only having a 1 speed fan and the Insulation factor is small. 3 tons (a/c only) seems about right for the area you live in (Michigan) should only struggle on hot days. The area I live, for a 2100sqf would be a 4 ton unit if the home is out in the open.

You need to change to a 3 speed motor. I dont think theres enough cfm going across that coil.

mh

[BigBacardi]

holy crap!!!!!! 4 tons in a mobile??????
r u for real?????

guess its dif up here in canada.....

dont they still use that crappy pancake duct in mobiles??? how would you get 1600 cfm thru a 16x6 duct????

just wondering....

[mh heating]

Thats will they're high static systems. Can we say Tornado type air flow, LOL Our average temp here in summer is about 98* and 1 to 3 weeks of 110+

[beerado4u]

Make sure all your duct work is connected below. (Crawl) ive came into numerous cases where it has been botched or animals used the flex to make a home. Since the homes are modular and ductwork is premade, thr final step is connecting both sides with large insulated flex together and the majority of times it falls off because of crap installers.

[Toddbrewster]

I dont remember the exact operating paramaters of the system but the superheat was 8-10, and subcooling was 12 or so. The home is about 12 years old I believe, I will be putting in the 3 speed blower soon and will double check the duct under the home lucky me its only 2 blocks off the ground, only other concern is by putting in the larger blower I hope I don't blow the flex off.