Context: 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.

Question: What percentage of energy in commercial buildings comes from HVAC systems?
Answer: 50

Question: How much energy does an HVAC system use in commercial locations?
Answer: 30% (4.65 EJ/yr)

Question: How much energy does an HVAC system use in residential locations?
Answer: 50% (10.1 EJ/yr)

Question: What can be used to balance out a portion of the energy used by HVAC systems?
Answer: Solar heating, cooling and ventilation technologies