Evaporator cooling capacity

[skyboy6142]

Hi friends,
I have an application that calculate cooling capacity of evaporators.
When I get output of software I see these two lines :

TOTAL HEAT TRANSFER RATE = 61403.7 BTU/HR
SENSIBLE HEAT TRANSFER RATE = 39856.7 BTU/HR

Which one is real cooling capacity of my coil for choosing compressor ?

Thanks for your replies in advance.

[Glide]

You should look at the total heat transfer.
The total heat transfer is the sum of sensible and latent heat transfer.

I will copy paste a text from Colmac Coil:


Whenever cooling coil surfaces operate at temperatures below the dewpoint of the air being cooled, water vapor in the
airstream is condensed to liquid (at temperatures above 32F (0C)) or deposited to form frost (below 32F (0C)). The
cooling effect associated with this dehumidification of the airstream is termed “latent” cooling.
The sum of the sensible cooling load and latent cooling load is termed the “total” load.

Page 4:
http://www.colmaccoil.com/media/39086/comparing-air-cooler-ratings-part-1.pdf

You can also sheck this definition from ASHRAE:


evaporator coil loads: the actual sensible heat and latent heat
removed from the distribution air by the evaporator coil. These
loads include indoor air distribution fan heat for times when
the compressor is operating, and they are limited by the system
capacity (where system capacity is a function of operating
conditions). (Also see sensible heat and latent heat.)

https://www.ashrae.org/file%20library/technical%20resources/standards%20and%20guidelines/standards%20addenda/140-2001_addendum-a.pdf

[sterl]

Your system capacity needs to support the total...but if you were trying to measure an evaporator's efficiency/ effectiveness, you need to know the sensible and latent components corresponding to at least 2 operating conditions or you will never be able to establish whether the coil is working well or not.