Heat loss and heat gain in buildings: Outside air (OA) (Additional information) Required to be brought inside a building envelope to continuously replace indoor air that has been contaminated with odors, carbon dioxide, and other air contaminants. While its is allowable to filter and re-circulate air to remove contaminants under certain circumstances, a minimum air exchange is necessary to decrease carbon dioxide buildup. Such air exchange may take place either through infiltration or ventilation.

Heat loss and heat gain in buildings: Outside air (OA) Infiltration (see section 15.2) Ventilation (see section 15.2) Calculation of hg/hl due to outside air (OA) (see sections 15.3 “Outdoor air heat losses” and 15.7 “Latent heat.”

Heat loss and heat gain in buildings: Outside air (OA) (Additional information) Specific Heat Quantity of heat required to raise the temperature of one pound of a material by 1°F. Specific heat of air = 0.24 BTU/lb/ °F. Other Pertinent Information At a rate of 1 Cubic Foot of airflow per minute, there will be 60 CFM an hour. 60 CFM = 4.5 lbs. Heat required to raise the temperature of 4.5 pounds of air = 0.24*4.5 = 1.08 BTUH/CFM/ °F. Heat released in condensation of 1 pound of water = 1060 BTU Heat released in condensation of 1 grain of water = 1060/7000 BTU Assuming a moisture difference of one grain per pound between inside and outside air, for 60 CFM of air there will be a difference of 4.5 grains. Heat released in condensation of that amount water = (1060/7000)*4.5 = 0.68 BTUH.