Monitor Data Corporation FAQ

Whenever a central boiler is shared by multiple apartments or condominiums for space heating, the total fuel consumption of the boiler must be divided into direct and indirect heat.  Direct heat is the energy radiated directly from the heating system within the living space and is controlled by the resident(s) with their thermostat setting.  Indirect heat represents the heat radiated from the shared boiler and the building heat distribution pipes.  Indirect heat is constantly lost from the central heating system during the entire heating season, and actually helps to heat the entire building, therefore reducing the need for direct heat within individual apartments and condominiums.  The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) refers to direct and indirect heat from a shared boiler heating system as monitored and non-monitored heat, and clearly states the need to follow this method of energy cost allocation in it's engineering guidelines.  This method of energy allocation is mandatory in many Western European countries.

For residents that maintain the lowest thermostat settings during cold weather, and for many additional residents during mild months, the indirect heat allocation may be greater than the direct heat allocation.  The sum of all apartment or condominium direct and indirect heat allocation will always equal the amount of fuel consumed by the shared boiler to heat those apartments or condominiums.