return size ?

[junior1]

i have this air handler TUD1C080A9H4 and i was suppose to install the return grill etc. due to wall repairs etc. my question is this will a 16x25 return be too small for a stand up furnace ? thats seems like the only one that would fit for the stand up unit. we didnt think about this when we did the box for the furnace to sit on. if i wanted to put a 20 x 25 return grille i would need to pick the unit up about 4 inches taller, which will affect the plenum because its already hitting the roof as it sits already. not much room up there to pick the furnace up a couple of inches.

[junior1]

anyone ?

[jhcoxx]

If you can do so, you might have better luck posting this in one of the Professional forums. Apparently there ain't no one here just now except us Home Owner chickens...

[dash]

i have this air handler TUD1C080A9H4 and i was suppose to install the return grill etc. due to wall repairs etc. my question is this will a 16x25 return be too small for a stand up furnace ? thats seems like the only one that would fit for the stand up unit. we didnt think about this when we did the box for the furnace to sit on. if i wanted to put a 20 x 25 return grille i would need to pick the unit up about 4 inches taller, which will affect the plenum because its already hitting the roof as it sits already. not much room up there to pick the furnace up a couple of inches.

How many cfms is the air handler moving???

!6X25 isn't good for a lot more then 800 cfms.

[DanW13]

What size return did your installer cut out on the side of your furnace ? I would think no matter what size return you have once you have the section of return duct coming out from the wall your installer should be able to transition it tothe side of the furnace and put the proper size filter rack in. Thats a 4 ton capacity is the AC you have 4 tons ?

[junior1]

i have a 4 ton coil and a 3.5 condensor with this air handler all trane and this setup will give me 14 seer by trane. i really dont know how to check cfm on the blower but i was the one to do the frame for the furnace to sit on due to hvac guy charging alot more to do a frame etc. i got a copy of data cooling.
it has values at ari ratings conditions, under it is total net capacity is 43000 btuh, and under this is airflow 1395 cfm, the next colum has correction factors-other airflows, under this is airflow 1225 1575

[junior1]

anyone?

[kytinknocker]

I would suggest you call your installer and have the make the proper transition 16x25 is not big enough.

[beenthere]

16 x 25 is too small.
Unless you like noise.

[junior1]

thanks guys what would be the correct size for a stand up air handler?
can a 20" X 25" work? i might be able do something with a 20x 25 with out having the hvac guy redo the plenum etc. due to space issues in attic. you guys have no idea how much i hate my attic right now. its too low and not helping me at all right now with the remodeling, but soon hopefully i will raise it maybe two years from now lol but its definitely on my list to do things.

[dash]

2 cfms per sq inch of return would be good,any way to add a second one??

[junior1]

dash i don't follow sorry for my ignorance on this matter,still learning.
the bottom opening of the air handler is about 19" long x 24" wide. so i though as long as th filter frame matched the opening of the air handlers size i would be OK but i ques this isn't so? so your saying a 20"x25" is still not big enough?

[dash]

dash i don't follow sorry for my ignorance on this matter,still learning.
the bottom opening of the air handler is about 19" long x 24" wide. so i though as long as th filter frame matched the opening of the air handlers size i would be OK but i ques this isn't so? so your saying a 20"x25" is still not big enough?

It may work,but will likely be noisey.


3.5 tons ,1400 cfms,divided by 2 = 700 sq in of grille.

700 divided by 25" = 28,so 25 X 28 return would be best,closer you can get to that the quieter it will be.