HVAC Systems Flashcards
Actuator
a device in a building control system that receives commands from a controller and activates a piece of equipment
Annual fuel utilization efficiency (AFUE)
the ratio of annual fuel output energy to annual input energy. This includes non-seasonal pilot light input losses
Coefficient of performance (COP)
a unitless number that is a rating of the efficiency of heating or cooling equipment. It is derived by dividing the steady-state rate of energy output (or the rate of heat removal, in the case of cooling equipment) of the equipment by the steady-state rate of energy input to the equipment . The output and input values must be in equivalent units, such as watts out to watts in
Controller
a device that measures, analyzes , and initiates actions in a building
Deadband
in a building control system, the range of temperature within which neither heating nor cooling is called for
Energy efficiency ratio (EER)
the ratio of net cooling capacity in Btu/hr to the total rate of electrical input in watts under designed operating conditions
Energy management system (EMS)
a computer-based system used to monitor and control facility energy use. An EMS is typically part of a building automation system
Ground-coupled cooling
a method of cooling a building by direct contract with the earth or by circulating air through underground tunnels to cool it
Heating season performance factor (HSPF)
a measure of the performance of a heat pump operating in the heating cycle.
Home energy rating system ( HERS)
a standardized system for rating the energy efficiency of residential buildings using the HERS council guidelines and the mortgage industry HERS accreditation procedures. A HERS score is a numeric value between 0 and 100 indicating the relative energy efficiency of a given home as compared with the HERS Energy- Efficient Reference Home.
Integrated part load value (IPLV)
the single-number figure of merit based on part-load EER or COP expressing part-load efficiency for air conditioning and heat pump equipment on the basis of weighted operation at various load capacities for the equipment, as determined using the applicable test method in the Appliance Efficiency Regulations
Relative solar heat gain ( RSHG)
the ratio of solar heat gain through a window, corrected for external shading, to the incident solar radiation. This heat gain includes directly transmitted solar heat and absorbed solar radiation, which are conducted or convected into the space.
Seasonal energy efficiency ration (SEER)
the total cooling output of a central air conditioning system or heat pump in the cooling mode, measured in Btu/hr (W), During its normal usage period for cooling divided by the total electrical input in watt-hours, as determined by specific test procedures. The higher the SEER, the more efficient the equipment performance. The minimum SEER for residential air conditioning equipment in the US is 13
