Condenser, Coil, Blower Sizing

[markgmoody]

Folks,

Could you tell me, in general, how you feel about the following combination of equipment. I know these are generalities but if you're looking at Trane gear with these capacities, what if any are the benefits/drawbacks?

3-ton condenser, SEER 13 3 1/2 ton coil 4 ton blower 80,000 BTU furnace 1500sq 2nd floor

Without being any kind of HVAC expert and without knowing any real specifics about how you might go about optimally setting the TXV for this configuration, my initial concern is:

1. blower load raising the avg temp of the coil and significantly reducing latent heat removal capacity. (but will moving more air across more coil surface area actually make up for the loss in latent heat removal caused by higher coil temp?)

[udarrell]

If the blower speed taps work out okay you can reduce the CFM to 350-CFM per Ton, or 1050-CFM. That will help to get a colder coil and increase run-time to reduce the humidity.

If the equipment is sized right it will have adequate runtime to handle the humidity and RM TH temp settings. Get a RM TH with at least two degrees differential between the on/off cycle for longer run-time cycles.

- udarrell - Darrell

[Oscar_Lives]

I feel good

(Like I knew that I would)

[Oscar_Lives]

How does a wider deadband increase run time? I thought that heat gain determined run time.

[markgmoody]

Thanks for the replies. Let me ask one last question just to settle my mind.

3 ton condenser, 3 ton coil, 4 ton drive

vs

3 ton condenser, 3.5 ton coil, 4 ton drive.

If I was at all concerned about humidity levels (living in the humid South), would going with the smaller coil get me more latent heat removal capacity or is the difference so small that its nearly insignificant?

[Oscar_Lives]

maybe.

[Noon-Air]

In the south you want a 3 ton condenser, a 4 ton coil(with TXV), and a 3 ton drive.