EXPLANATION OF HOW SUGGESTED HVAC VENTILATION INCREASE IMPACTS GLOBAL WARMING 100% OUTDOOR AIR CIRCUIT OUTDOOR AIR EXHAUST AIR 100% AUTOMATIC DAMPERS 100% AVERAGE OUTDOOR AIR TEMP. = 30°F AVERAGE SUPPLY AIR TEMP. = 30°F CONSTANT ROOM TEMP. = 70°F D1 D2 D3 PERCENTAGE OUTDOOR AIR = 100% 0% PERECENTAGE EXHAUST AIR = 100% RECIRCULATED HEAT = 0% ∆T OF SUPPLY AIR TO ROOMS = 40F° SUPPLY FAN RETURN FAN SUPPLY AIR RETURN AIR TO OTHER ZONES 30°F 70°F FROM OTHER ZONES (AVERAGE) (CONSTANT) HEATING COIL (TYPICAL) AVERAGE ∆T SUPPLY AIR TO ROOMS = 40F° ROOM (TYPICAL) 70°F CONSTANT NOTE: INCREASED CLIMATE CHANGE DAMAGE AT TWO DIFFERENT POINTS: The direct heat increase, via exhaust air, into the atmosphere from altering to the 100% outdoor air circuit is 670%. The ni creased GHG emissions, caused by increasing the ∆T of the supply air to the rooms is 700%. This is worst case scenario, as most systems' safeties disallow this alteration, but various percentages are achievable. Disabling all Demand Control Ventilation (DCV), as per ASHRAE suggestions, reverts to minimum supply temperature set point causing at a 417% increase in exhaust heat and at a 333% increase in GHG emissions to atmosphere. This is best case scenario. ASHRAE altered from suggesting 100% outdoor air, but many governing authorities do not know this fact. ASHRAE's position of disabling DCV remains, based on available papers. If the live virus cannot travel through the turbulence of the HVAC fans and return alive to the occupied spaces, the alterations in the HVAC equipment presents no benefit, as the supply air should have the same live virus content before and after the alterations; however, the alterations are extremely damaging regarding global warming. 11.190 1 D2 85% CONSERVATION CIRCUIT AVERAGE OUTDOOR AIR TEMP. = 30°F OUTDOOR AIR 15% EXHAUST AIR AUTOMATIC DAMPERS 15% AVERAGE SUPPLY AIR TEMP. CONSTANT ROOM TEMP. PERCENTAGE OUTDOOR AIR PERECENTAGE EXHAUST AIR RECIRCULATED HEAT ∆T OF SUPPLY AIR TO ROOMS = 64°F = 70°F = 15% = 15% = 85% = 6F° D D3 SUPPLY FAN RETURN FAN SUPPLY AIR TO OTHER ZONES 64°F (AVERAGE) RETURN AIR 70°F FROM OTHER ZONES (CONSTANT) HEATING COIL (TYPICAL) AVERAGE ∆T SUPPLY AIR TO ROOMS = 6F° ROOM (TYPICAL) 70°F CONSTANT
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