Glossary
Categories
Heating Definitions
ACH
Air Changes per Hour. ACH is the number of times that the air in your home is completely replaced with outside air.
AFUE
Annualized Fuel Utilization Efficiency.
Air
The mixture of oxygen, nitrogen and other gases and water vapor that form the earth’s atmosphere.
Air Handler
An Air Handler mixes or moves air.
Air Separator
A device that is fitted to central heating system that eliminates small air bubbles circulating the water system. Air in the system creates circulation noise and corrosion.
Air Vent
A valve placed at the highest point of a heating unit for venting air.
Aquastat
This is a safety device often used on boilers to limit water temperature.
Backflow
Backflow is the flow of water back to the main water supply.
Blower
A fan used to force air.
Boiler
A Boiler is a type of equipment that converts liquid into a vapor. A boiler consists of a furnace where propane, natural gas, oil or wood is burned. It then transmits the heat from the combustion products to the water or liquid where it is the distributed through out the house by way of pipes.
BTU
British Thermal Unit. The quantity of heat needed to raise the temperature of one pound of water one degree Fahrenheit. An example of a BTU is burning one wooden match.
Calorie
A calorie is the amount of energy it takes to heat one gram of water one degree Celsius.
Capacity
The BTU production ability of a heating or cooling system.
Celsius
A metric measurement. On this scale water freezes at zero and boils at 100.
CFM
Cubic Feet per Minute. This is a standard measurement of airflow.
Check Valve
A non-return valve where water may only pass in one direction.
Circulation Pipe
The main water flow and return pipes to and from the central heating boiler.
Circulation Pump
A mechanism used to pump water to the central heating system.
Cleanout Door
A door that allows for cleaning of accumulated debris.
Coil
A heating element in a domestic hot water tank. It circulates water from the boiler to the tap.
Cold Feed
A Cold Feed allows cold water from the header tank into the system.
Combustion
The burning of fuel using air.
Condensate
Condensed water that results from the removal of latent heat from steam.
Condensing Boiler
A high efficiency boiler that recovers heat from flue gases that would have been lost to the atmosphere.
Conduction
The transfer of heat through a solid material.
Conduction
The transmission of heat through a medium without a lot of movement by the medium.
Convection
The transfer of hear by air flow.
Crude Oil
Unrefined petroleum.
Damper
Dampers are movable plates which control and balance airflow. They are found in ductwork.
Diffuser
A grill which covers an air supply duct. It allows for distribution in a specific pattern or direction.
Distilled Water
Water produced by vaporization and condensation resulting in higher purity.
Duct
A passageway which allowing for the installation of pipes, cables, etc.
Duct for Warm Air
This is a system where gas is combusted creating hot air and then distributed through the residence.
EER
Energy Efficiency Ratio. EER is a measurement of air conditioning or heat pump efficiency. The higher the EER the more efficient.
Efficiency
The ratio of output to input.
Electric Boiler
An Electric Boiler uses electricity to create heat verses oil or propane.
Energy Star
High efficiency systems carry this Energy Star label. Products with this label are more efficient and help to reduce our whole earth’s pollution problems. Energy Star systems are also known to lower energy bills.
Expansion Tank
This is a small tank used in a central heating systems which absorbs water pressure and extra volumes of hot water as it is heated. The tank contains a rubber diaphragm that squeezes small volumes of air in the tank as the water expands. This whole action relieves pressure on the tank and on the system as a whole.
Flue
The Flue is where the fumes from burned gas go.
Furnace
An enclosed space which provides for the combustion of fuel.
Greenhouse Effect
The effect of the Earth’s atmosphere, due to certain gases, trapping heat from the sun and acting like a greenhouse.
Greenhouse Gases
The major Greenhouse Gases include Water Vapor and Carbon Dioxide. Small amounts of methane, ozone, chlorofluorocarbons and nitrogen oxides are also found.
Heat Exchanger
An area where heat flows from the warmer to the colder fluid surface.
Heat Gain
Heat which is added to the conditioned space by infiltration such as, solar radiation, lighting, etc.
Heat Load
The amount of heat required to be removed within a certain period, usually 24 hours. Usually measured in BTUs.
Heat Loss
Heat Loss is the rate of heat transfer from a heated space to the outside.
Heat Pump
In the summer a Heat Pump is basically an air conditioner with a valve that allows for operation in reverse, removing heat from your home. In the winter the Heat Pump removes heat from outside and delivers it to your home.
HVAC
Heating, Ventilation and Air Conditioning.
Insulation
Insulation, most commonly made from fiberglass, resists the transfer of heat. It is rated in terms of thermal resistance or R-Value. The greater the R-Value the more effective. There are many types of insulation other than fiberglass: rockwool, cellulose, perlite, vermiculite, rigid board, etc.
Kerosene
Kerosene (K-1) is light and very clean burning heating oil.
Kilowatt (kW)
One kW is equal to 1000 Watts One Watt is defined as one Joule of energy released per second. 1kW is equivalent to 3414 BTUs.
Latent Heat
Latent Heat is a type of heat that when added to a substance or taken from a substance does not change the temperature of the substance. Instead the heat energy allows for the substance to change its state.
Low Water Cutoff
Safety device that shuts off the boiler in the event of low water.
Mains Water
Water supplied by the utility district or water company.
Manifold
A header for collection and distribution of fluid throughout the home.
Modulating Burner
Automatically adjusts gas throughput dependant on temperature and demand.
Natural Gas
Gaseous fuel occurring in nature.
Natural Gas Powered Boiler
Natural Gas is a clean fuel that has the least damaging effect on the environment of other fossil fuels. It is the most inexpensive alternative in terms of running costs. Also Natural Gas is mains supplied therefore it requires no storage. However, the supply isn’t available to everyone.
Nozzle
A short flanged or welded neck connection on a drum or shell for the outlet or inlet of fluids.
Oil
A black liquid fossil fuel found deep in the Earth. Gasoline and most plastics are made from oil.
Oil Powered Boiler
Oil Powered Boilers are the most popular alternative when there is no mains supply of natural gas. However, oil is not the cheapest option today. Price of oil changes seasonally and varies with local.
Open Flue
An appliance that takes in air for combustion from within the room it is fitted.
Open System
A system that has an expansion tank open to the atmosphere.
Peak-Hour Demand
Peak Hour is the hour at which the demand for water in the highest.
Pilot Light
A small gas flame which is kept alight in order to serve as an ignition source.
Primary
The flow pipe from the boiler to pump before any motorized valve.
Primary Heat Exchanger
Main Heat Exchanger in a boiler.
Programable Thermostat
This is a thermostat that has the ability to schedule different temperature settings for different times of day.
Pump
A pump is a devices used to circulate water around the central heating system.
R-Value
R-Value measures heat resistance. The higher the value the better the insulation resists heat transfer.
Radiator
A radiator transfers heat from hot water to the space in a room.
Relay
An electrical component used to “call” for heat.
SEER
Seasonal Energy Efficiency Ratio. SEER measures the average cooling efficiency of your heat pump or air conditioner over the entire cooling season.
Solid Fuel Boiler
This is a Boiler that does not burn a liquid such as gas or oil. Instead a Solid Fuel Boiler will burn coal, wood, pellets, etc.
Standby Losses
Storage water heater looses heat by conduction through the walls of the tank and the first few feet of piping.
Storage Capacity
The gallons of hot water a storage tank can hold.
System Capacity
The total BTU amount of heating or cooling your system can produce in one hour.
Thermostat
A series of sensors and relays that monitor and control the function of a heating and cooling system.
U-Value
U-Value measures heat flow. The lower the value the slower the material transfers heat in and out of your home.
Vacuum
A pressure below atmospheric pressure.
Valve
A device that regulates the flow of fluids by opening, closing or partially obstructing various passageways.
Ventilation
Ventilation is the intentional movement of air from the outside to the inside.
Zone Valve
A Zone Valve is a specific type of equipment used to control the flow of water or steam (in a hydronic system) allowing heat to be directed at specific zones.
Zoning
Zoning controls space heating for separate rooms or parts of a building or home for comfort. This allows each zone (or room) to be independently controlled.