In the United States, heating, ventilation and air conditioning (HVAC) systems account for 30% (4.65 EJ/yr) of the energy used in commercial buildings and nearly 50% (10.1 EJ/yr) of the energy used in residential buildings. Solar heating, cooling and ventilation technologies can be used to offset a portion of this energy.
Try to answer this question if possible (otherwise reply "unanswerable"): How much energy does an HVAC system use in commercial locations?
30% (4.65 EJ/yr)