Load and Energy Calculations
Load Calculation Procedures. Refer to the ASHRAE
Handbook, Fundamentals, for the acceptable method of performing
load and energy calculations.
Load Calculation Form. Except for small buildings and
minor renovation, less than 8000 square feet, loads should be
calculated using a computer program which applies one of the
methods in the ASHRAE Handbook, Fundamentals, Chapters 25 and 26.
Simplified load calculation equations are reproduced in Section 5
of this handbook. These simplified equations may be used on
smaller buildings with hand calculations.
Design Conditions. Select indoor and outdoor summer
and winter design conditions in accordance with MIL-HDBK-1190.
If a known micro-climate condition exists at the site, or if
building site location is not shown in NAVFAC Publication P-89,
Engineering Weather Data; consult the Navy design manager or
project leader (DM or PL) for instructions.
Variable Air Volume (VAV) Systems. For VAV systems,
refer to Appendix C and ASHRAE Handbook, Fundamentals, for the
Outdoor Air Load
a) Infiltration. Use infiltration rates and the
method of calculation prescribed in ASHRAE Handbook,
b) Ventilation. Use ventilation rates for IAQ
prescribed in ASHRAE Standard 62, Ventilation for Acceptable
Indoor Air Quality and the method of calculation included in
ASHRAE Handbook, Fundamentals.
Building Orientation. Building orientation,
fenestration, lighting, and geometry can have a profound effect
on the building energy consumption, system selection, and zoning.
Therefore, the HVAC designer should consult with the architect
during the early concept stage to optimize the overall design.
Architectural Features. The building mass, tightness
of construction, window treatment, occupancy zoning, and other
characteristics can also impact the HVAC design. These features