Occupancy Sensors

Occupancy Sensors – A device that switches lights on and off or dims and brightens them based on the presence or absence of people. Occupancy sensors are often based on motion detectors and/or infrared sensors.

Passive Solar (Building) Design – A building design that uses structural elements of a building and area landscape to heat and cool a building without the use of mechanical equipment. The principal elements include proper building orientation and location, proper window sizing and placement and design of window overhangs to reduce summer heat gain and ensure winter heat gain, and proper sizing of thermal energy storage mass. The heat is distributed primarily by natural convection and radiation, though fans can also be used to circulate room air or ensure proper ventilation.

Passive Solar Heater – A solar water or space-heating system in which solar energy is collected, and/or moved by natural convection or existing water line pressures without using pumps or fans. Passive systems are typically integral collector/storage (ICS or batch collectors) or thermosyphon systems. The major advantage of these systems is that they do not use controls, pumps, sensors, or other mechanical parts, so little or no maintenance is required over the lifetime of the system.

Peak Demand/Load – The maximum energy demand or load in a specified time period. Regional energy requirements are limited by the total energy demanded on the system during the hours of maximum use. Some power utilities offer discounts for energy usage during off-peak hours. Depending on the energy need and the amount of discount, some facilities include systems that use power in off-peak hours to cool or heat thermal storage systems for use later in a passive mode during peak hours.

Photovoltaic (Solar) Module or Panel – Groups of photovoltaic (PV) cells electrically connected to produce a specified power output under standard test conditions. The PV cells are mounted on a substrate, sealed with an encapsulant, and covered with a protective glazing, and sometimes further mounted on an aluminum frame. A junction box, on the back or underside of the module is used to allow for connecting the module circuit conductors to external conductors.

Propane – A hydrocarbon gas, C3H8, occurs in crude oil, natural gas, and refinery cracking gas. It is used as a fuel, a solvent, and a refrigerant. Propane liquefies under pressure and is the major component of liquefied petroleum gas (LPG). Propane typically produces less NOx than gasoline.