Upgrading AC unit

[Paul]

What problums might you encounter when installing a 3.5 ton ac unit in mobile home. The condensor will be a Rheem 3.5 ton with matching a coil and a new blower installed. What I need to know is if this is feasible and how to size the blower for this system. I am a certified contractor but do not normally work on mobile homes so any advice would be appreciated. Assume that a Manual J calculation has been done and unit size is correct.
Paul

[Robert]

Hi Paul,


What is the brand and model number of the furnace ? As long as the a-coil is upflow or downflow depending on the home and physically fits in the space, should be fine.


If it is a downflow and an electric furnace where coil sits at top above all, be sure to install a trap in the drain line (good to do anyway).


The blower must be designed for use in the small mobile home duct systems. If it has a mobile home furnace, can give correct blower info with brand and model number.





Thanks,
Robert

[Paul]

Do not know the brand or model number. It was a job that we were looking at installing a trailer package air unit but we lost the job to a trailer company and they installed the system I asked about and I was courious to see if what they were doing would work on a trailer. What is the difference between a mobile home blower and a residential blower. Does it have a higher or lower CFM and is this due to a different speed motor or is the fan different?
Thanks
Paul

[Robert]

Hi Paul,


Probably worked fine. Just have to make sure a-coil dimensions fit in the smaller spaces and get up or downflow accordingly as needed.


The blower problem is the very small mobile home ductwork and the change in static pressure.

Either need to get a mobile home designed blower for it or install conventional housing duct system and go with normal blower.


What I tell folks is get some external static pressure readings in regular housing duct systems, then do same in a mobile home and see the difference.



7X12, 8X14 are normal mobile home duct sizes in rectangular shape.


Very thin and flimsy aluminum (cheaply made).


Package units are the same, best to get one normally designed for mobile homes to have correct blower in it.


Coleman, Nordyne (Intertherm and Miller), Goodman are most well known plus others.



Thanks,
Robert