Research on technology clusters and the energy efficiency of energy-saving retrofits of existing office buildings in different climatic regions

Table 5 Constraint and guide values for the non-heating energy consumption indexes of office buildings [kW h/(m² a)] (source: Standard for Energy Consumption of Building(GB/T51161–-2016))

Building class		Cold and severe cold regions		Hot-summer cold-winter regions		Hot-summer warm-winter regions		Mild regions
Building class		Constraint value	Guide value	Constraint value	Guide value	Constraint value	Guide value	Constraint value	Guide value
Class A	Office buildings of party and government agencies	55	45	70	55	65	50	50	40
Class A	Commercial office buildings	65	55	85	70	80	65	65	50
Class B	Office buildings of party and government agencies	70	50	90	65	80	60	60	45
Class B	Commercial office buildings	80	60	110	80	100	75	70	55

The running time of the system in a class A building can be reduced by opening exterior windows to utilize natural ventilation; however, class B buildings need to rely on mechanical ventilation and air conditioning systems all year round