Evolution AC Airflow Setting

C

Clocker

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Discussion starter · #1 · Aug 29, 2011

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Howdy guys-
I have an Evolution furnace (355CAV 80K BTU) with Evolution control. My AC unit is just a single stage 3-ton (non-Evolution) Bryant 116B.

I have 4 settings on the stat for airflow control during AC operation:

Comfort (default): This one appears to run the furnace fan at a lower speed for a while before kicking it up a notch. I assume it is to help dehumidify a little more?
Efficiency 325: I assume this means 325CFM/ton (975CFM)
Efficiency 350: I assume this means 350CFM/ton (1050CFM)
Maximum: 400CFM per ton (based on the manual)

Just curious why there are two Efficiency settings and what are the pros/cons of each? Any thoughts?

 

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21degrees

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#2 · Aug 29, 2011

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the lowest setting is for dehumidification, it basically overcools, where as 400 cfms will get air there quickly but leave some more humdity in air. Some people like strong fan, some people like to have more control over humidity
I pick lower humidity

 

C

Clocker

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Discussion starter · #3 · Aug 29, 2011

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Thanks for your feedback.

Would the 350CFM/ton setting be more efficient at cooling that the 325CFM/ton setting for my 3ton unit (assuming the difference in humidity is negligible)?

 

C

Clocker

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Discussion starter · #4 · Aug 29, 2011

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FWIW:

Air Handler: Bryant CAC/BDP CNPVP3617ACA
Outside Unit: Bryant 116BNA036000

Thanks!

Clocker

 

teddy bear

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#5 · Aug 29, 2011

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What is your indoor %RH and where do live?
Regards TB

 

C

Clocker

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Discussion starter · #6 · Aug 29, 2011

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teddy bear said:

What is your indoor %RH and where do live?
Regards TB

Click to expand...

~43%

SE Michigan

Thanks!

 

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fixitmanmc

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#7 · Aug 30, 2011

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The way I compare it from UTC's product data @ TVA specs;

1350 cfm = 25.72btu sensible @3.04kw 25.72/3.04=8.460
1200 cfm = 24.22btu @2.98kw 24.22/2.98=8.127
1050 cfm = 22.63btu @2.92kw 22.63/2.92=7.75

looks to me like more sensible btu bang for buck at higher airflow.
[They do not provide test data @ 325 per ton.]

Please correct me if I'm wrong.