| absorption chiller |
water chiller based on absorption of refrigerant vapor into a liquid
solution, pumping of the solution to elevated pressure, and the release
(desorption) of refrigerant vapor through addition of heat; absorption
chillers require less energy because the pumping process involves
a liquid; direct-fired chillers employ natural gas burners, indirect-fired
chillers use steam or hot water from a separate process (such as
the hot exhaust gases from electric generation); single-, double-,
and triple-effect chillers employ multiple stages of desorption and
internal use of waste heat to boost efficiency
|
| demand charge |
charges for the use of electricity based on the maximum power requirement,
electrical demand, during a specified period of time, typically a month
($/kW)
|
| desiccant |
a solid or liquid material with an affinity for absorbing water
molecules
|
| engine-generator |
electrical generator using a reciprocating, Sterling, or rotary
engine
|
| enthalpy wheel |
heat exchanger rotating through building supply and exhaust air
flows to transfer energy from one air stream to the other
|
| evaporative cooling |
lowering the temperature of air through the evaporation from a water
or wetted membrane; direct evaporative cooling adds water to the supply
air while indirect evaporative cooling adds water to the exhaust air
and incorporates a heat pipe or thermal wheel for indirect cooling
of the supply air
|
| fuel cell |
device for producing electricity using a chemical process rather
than conventional combustion processes with electric generators
|
| heat wheel |
heat exchanger rotating through building supply and exhaust air
flows to transfer heat from one air stream to another
|
| latent cooling load |
amount of cooling required to reduce humidity of air in conditioned
space to specified level for comfort
|
| microturbine power generator |
turbine-engine driven electrical generator with output power under
100 kW
|
| real time pricing |
charges for electrical demand and consumption based on instantaneous
cost of production and distribution as opposed to fixed rates or fixed
time-of-day rates
|
| sensible cooling load |
amount of cooling required to reduce the temperature of air in the
conditioned space to a specified level for comfort
|
| thermal wheel |
heat exchanger rotating between two air flows to transfer heat from
one to the other
|
| ton or refrigeration ton |
quantity of cooling available from melting 2000 pounds of ice; 12,000
Btu/h or 3.1413 kW
|
| vapor compression air conditioning |
cooling system based on compression of a gaseous refrigerant to
a high pressure, and heat transfer with changes of state (i.e. liquid
and vapor) to produce useful heating or cooling
|
| waste heat |
portion of the energy input to a mechanical process which is rejected
to the environment |
