Air Handler for central HVAC unit

[buckle97]

I want to add a central air and heat system to my old house. I have a few questions related to the air handler being placed in my attic.

1. I have 2 x 4 ceiling rafters. How much bracing do I need to put under the air handler?

2. How is the best way to get the air handler in the attic? I haven't yet installed attic stairs; would it be best to have the air handler put through the hole cut for the stairs before the stairs are installed?

3. I see that many attic stairs have a low weight limit; how are air handlers in attics replaced in houses with attic stairs?

 

[Junkman]

Rather than installing it on the floor, you could consider hanging it from the roof rafters. I have been told that that method is quieter. It also depends on how strong your roof structure is.

 

[Deerlope]

Outside is the best place for them. They don't take up much space. You might hear it running in the attic, and they do have to have a drain away from them.

 

[thcri]

Rather than installing it on the floor, you could consider hanging it from the roof rafters. I have been told that that method is quieter. It also depends on how strong your roof structure is.

That is the way we install them. Hang them from the rafters to absorb noise. Also put a double drain pan underneath the air handler.

Have one guy in the attic and two guys to push up through opening whatever you have. Typically there is already an access in most houses. Sometimes we have to make them larger.

Make sure the furnace your putting up there can handle freezing conditions??

murph

 

[buckle97]

I like the idea of hanging it from the rafters. I will have to check the strength of my roof!

Also put a double drain pan underneath the air handler.

Does the drain pan rest on the ceiling joists?

Make sure the furnace your putting up there can handle freezing conditions??

You obviously didn't look at my location!

 

[dzalphakilo]

Don't forget, just as important, due to your climate, DON'T skimp on the ductwork materials if this system is going into an unconditioned space (attic). During summer months in the attic, if unconditioned, you can get to over 120 degrees easily on a regular basis in the area where your HVAC equipment is located, and if the ductwork isn't done "good", it will have an effect on the performance of your equipment (particularly your air discharge temp from your registers, which will determine how well you can maintain how cold you want it).

Just food for thought.

P.S forgot to add, spend the extra money for variable speed, it is worth every penny.

 

[thcri]

I like the idea of hanging it from the rafters. I will have to check the strength of my roof!

Does the drain pan rest on the ceiling joists?

We tpically use threaded rod and green slotted strut. Make your rods go past the air handler and down to handle the pan also.

You obviously didn't look at my location!

This is because I did not know where I was when I typed this. But as I was saying since your way in the south you don't need to worry about freeze ups. But since you are way down south make sure you have good insulation with all that humidity.

murph

 

[Cowboyjg]

There shouldn't be any issue with roof strength and supporting the air handler. Your trusses are designed for the top chord to be load bearing. I would also suggest a float switch in the pan to kill the unit if by some strange chance the pans fill. Also, and I know I may ruffle some feathers here but, you can use 3/8" eye bolts, placed through predrilled holes in the center of the vertical face of the rafter at each point where the threaded rod meets the rafter. Turn the eye bolt so the rod runs through it. Use a washer and double nut on the rod that runs through the eye bolt. Of the many methods I've used that has been the easiest to assemble and disassemble if needed. You should consider some plywood on top of the bottom chord to serve as a service platform.