When measuring the wall height to determine the wall area, it's clear the measurement should be floor to floor for return air plenums. Then the appropriate percentage is used in the wall-to-plenum heat gain field of the System's duct system data.

How many HAP users still measure floor to floor when there is ducted return? Have you then entered the wall area by measuring floor to ceiling to check the effect on the load? What is that effect?

It is such a hassle to re-enter the wall area if the system changes from return air plenum to ducted return. It would seem the safest assumption is to enter wall areas by measuring wall height from floor to floor. Do you agree?

PH MECHANICAL ENGINEERING
Reba Schaber Mechanical Engineer, P.E.
LEED Accredited Professional
1660 N. Alvernon Way Voice: (520) 731-2060
Tucson, Arizona 85712 Fax: (520) 731-2061
rschaber at phmech.com