2,400+ Definitions
HVAC GLOSSARY
Every HVAC term, acronym, and industry phrase — defined in plain English.
Service Valve
A service valve is a manually operated valve installed on…
Setpoint
A setpoint is the target temperature that an HVAC system…
Setpoint Reset
Setpoint reset automatically adjusts the temperature or pressure target based…
Shaded Pole Motor
A simple single-phase induction motor that uses a short-circuited copper…
Shaft Grounding Ring
A device mounted on the motor shaft that uses conductive…
Sheet Metal Work
Sheet metal work encompasses the cutting, forming, and joining of…
Shell and Tube Heat Exchanger
A shell and tube heat exchanger transfers heat between two…
Shop Drawing
A shop drawing is a detailed construction document prepared by…
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…
Silver Brazing Alloy
A filler metal containing silver (commonly 0 to 56 percent)…
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…
Single-Zone Mini-Split
A ductless system consisting of exactly one outdoor unit connected…
Site Energy
Site Energy is the total amount of energy delivered to…
Slab-on-Grade Radiant
A radiant heating system in which tubing is embedded in…
Slim Duct Indoor Unit
A low-profile ducted air handler designed for installation in shallow…
Sling Psychrometer
A hand-held psychrometer mounted on a swivel handle that is…
Slinky Loop
A horizontal geothermal loop configuration where the pipe is coiled…
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…
Snowmelt System
A hydronic radiant system embedded in pavement, driveways, or walkways…
Soft Starter
A soft starter is an electronic device that gradually increases…
Sol-Air Temperature
An equivalent outdoor temperature that combines the effect of solar…
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…