Blower output distance to A-coil

[Steve R]

I acquired a 3.5 ton central air unit with matching A-coil assembly (a-coil and the box it is mounted in) to install in my garage. I need to attach a blower to the a-coil and I have a blower out of a furnace to use. Is there a minimum distance the blower output should be from the a-coil? If I mount the blower to the top of the a-coil box it will be about 4 inches about the a-coil.

Thanks

 

[fitter30]

Typical residential air handler coil is on the return side of blower 8" - 10" between blower and coil. Condensate line has to be trapped. Factories designed ahu are engineered for even air flow across the coil. Using a coil in cabinet on the return side vrs supply should help with evening out the air flow.

 

[Steve R]

So it draws air through the coil rather then push air through, is that correct?

 

[yeldogt]

They do have downdraft units .... most systems are set up with the blower under the A coil blowing up.

 

[Yankeefarmer]

So it draws air through the coil rather then push air through, is that correct?

That’s the way my air handler is set up. Return air enters at bottom, flows up through the coil, then enters the blower for distribution to the supply duct(s). Like @fitter30 notes, that helps with more even air distribution through the coil.

 

[Steve R]

Connection for the condenser to turn it on. They show using the "Y" connection on the thermostat going to condenser contact and then back to chassis for ground. I will not be using a thermostat, just a on/off switch. Can I piggy back off the "G" connection for the fan without causing any issues. I did get the blower to work and once the switch is turned on it waits about 8 seconds and blower kicks in, when I switch it off, the blower continues to run for another 60 seconds which from what I read is the correct operation.

Thanks

 

[fitter30]

If your using a furnace thermostat terminal strip, transformer and board the times the start / off delay.
Y and C power the condenser
R to Y jumper wire - turns on condenser
R to G jumper wire - blower

 

[Steve R]

There is no "Y" on the control board on R G W. That was why I was asking if I could connect condenser power along with blower power on "G".