2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
Short Circuit Current
Short circuit current (SCC) is the maximum current a photovoltaic…
Short Cycling
Short cycling occurs when a compressor starts and stops at…
Shut Off Valve
A shut off valve is a device that stops water…
Sick Building Syndrome
Sick Building Syndrome (SBS) describes a cluster of health symptoms…
Sidearm Water Heater
A sidearm water heater is a compact, tankless heat exchanger…
Sight Glass
A sight glass is a transparent viewing port installed in…
Significant New Alternatives Policy
The Significant New Alternatives Policy is the EPA’s comprehensive regulatory…
Single Axis Tracker
Single axis trackers rotate photovoltaic panels along one axis, typically…
Single Line Diagram
A Single Line Diagram is a simplified schematic representation of…
Single Phase
Single-phase power is an alternating current system with one active…
Single Stage Furnace
A single stage furnace is a heating system designed to…
Single Zone Unit
A single zone unit is a heating, ventilation, and air…
Site Energy
Site Energy is the total amount of energy delivered to…
Slot Diffuser
A slot diffuser is a linear air distribution device featuring…
Slugging
Slugging occurs when large volumes of liquid refrigerant unexpectedly enter…
SMACNA
SMACNA (Sheet Metal and Air Conditioning Contractors’ National Association) establishes…
Small Appliance Category
The Small Appliance Category encompasses refrigeration and air conditioning equipment…
Smart Grid HVAC
Smart Grid HVAC systems integrate advanced sensors, controls, and communication…
Smart Home
A Smart Home is a residential property equipped with interconnected…
Smart Home Energy Management
Smart home energy management integrates automated controls for heating, cooling,…
Smart Meter
A smart meter is an advanced utility meter that records…
Smart Register
A smart register is an electronically controlled vent damper that…
Smart Thermostat
A smart thermostat is an internet-connected control device that learns…
Smart Thermostat Integration
Smart thermostat integration connects intelligent temperature control devices to home…
Smart Vent
A smart vent is an intelligent ductwork device that automatically…
Smoke Damper
A smoke damper is a motorized or automatic closure device…
Smoke Detector Integration
Smoke detector integration refers to connecting standalone smoke detection systems…
SNAP Program
The Significant New Alternatives Policy (SNAP) Program is EPA’s regulatory…
Soft Starter
A soft starter is an electronic device that gradually increases…
Solar Absorption Chiller
A solar absorption chiller converts solar thermal energy into cooling…
Solar Air Conditioner
A solar air conditioner is a cooling system powered by…
Solar Appraisal
A solar appraisal is a professional assessment that determines the…
Solar Array
A solar array is a collection of multiple solar panels…
Solar Assisted Heat Pump
A solar assisted heat pump integrates solar thermal collectors with…
Solar Backfeed Breaker
A solar backfeed breaker is a specialized circuit breaker designed…
Solar Battery Bank
A solar battery bank is a collection of individual battery…
Solar Battery Storage
Solar battery storage systems accumulate excess solar energy for use…
Solar Billing
Solar billing encompasses the billing methods and compensation structures utilities…
Solar Buyback Rate
The solar buyback rate is the price per kilowatt-hour that…
Solar Canopy
A solar canopy is a shade structure with integrated photovoltaic…
Solar Carport
A solar carport is a parking structure with integrated photovoltaic…
Solar Cash Purchase
A solar cash purchase is an all-cash investment where a…
Solar Cell
A solar cell is the fundamental semiconductor device that converts…
Solar Charge Controller
A solar charge controller regulates power flow from solar panels…
Solar Clipping
Solar clipping occurs when an inverter reaches its maximum power…
Solar Collector Efficiency
Solar collector efficiency is the percentage of incident solar radiation…
Solar Combiner Box
A solar combiner box consolidates electrical connections from multiple photovoltaic…
Solar Combisystem
A solar combisystem integrates solar thermal collectors to provide both…