Latent Load Calc.
Latent Load Calc.
(OP)
When calculating the Latent load portion of the heat load to a space, I have been using .68*CFM*(delta w). I know this equation is based on the formula Q=m*CP*(delta T), but can't figure out how it is derived. Can someone help out?





RE: Latent Load Calc.
That energy equation is used to derive the energy equation for sensible heat load.
To Calculate the latent heat load, the energy equation starts:
QL=Mw*change in enthalpy=Ma*change in humidity ratio*latent heat of vaporization.
Mw=mass flow rate of water
Ma=mass flow rate of air
humidity is grain / lb of dry air
The constant .68 is the product of air density of 0.075 lbm/ft3, a latent heat of vaporation at approximate partial pressure of water vapor in the air 1061 Btu/lbm and 60 min/hr. the product then divided by 7000grain /lb of water.
i hope this help
smb168