Types, Terms and Temperature: A Complete Space Heater Glossary

A measure of how much electric current an appliance will need to operate.

Auto safety shut-off
A common safety feature on most portable heaters, this function turns off the heater when it reaches a certain temperature, in order to reduce the risk of overheating and fire.

Baseboard Heater
A narrow, low-profile heater designed to fit along the base of a wall. They don't have internal fans, which means operation is silent. Heat is circulated naturally through the room by convection. Most baseboard heaters range between 500 and 1500 watts, which heats between 50 and 150 square feet.

Abbreviation for British Thermal Unit, a standard unit of measurement used in the heating and cooling industry. One BTU is approximately the amount of energy needed to heat one pound of water. It also is the amount of heat generated by one lighted matchstick. For heaters and heating systems, the BTU rating describes how much heat a unit is capable of producing each hour, and is directly related to how big a space a heater can keep warm.

Ceramic Heater
Operate by sending electricity through metal wires embedded in ceramic plates. As the plates warm up, they transfer heat to aluminum baffles, and then a fan blows air across the baffles to distribute heat through the room. Ceramic heaters are considerably more efficient than traditional electric heaters, because the ceramic plates continue to radiate heat even after the electricity is disconnected. They are also safer because there are no exposed heating coils.

An abbreviation for "cubic feet per minute" and a measurement of airflow, or how much air a fan can move. CFM is calculated by the following formula: air speed (feet per minute) X area (square feet) = CFM. or something along those lines. This measurement only applies to heaters with internal fans.

Convection is the process by which heat is transferred from one place to another. In the most practical terms for heating systems, it is the principle that "heat always rises." When a heater is placed low to the ground, the heat it produces will naturally rise and displace the air near the ceiling. This cooler air is pushed down where it is, in turn, warmed by the heater until the temperature in the entire room is at equilibrium. Convection can be "forced" with an internal fan or "natural", which heats a space more slowly but is quieter.

Diathermic Oil
Heat transfer oil used in oil-filled radiators. See oil-filled radiator heater.

Electric Heater
Electric heaters run an electric current through a heating element, causing it to rise in temperature. They have to be plugged into an electrical outlet or connected to household wiring to function.

FE9416 Image1Fireplace Heater
Fireplace heaters are a great way to enjoy the look and feel of a wood fire even without a conventional fireplace. Electric fireplaces operate on standard voltage and can warm up to 450 square feet. Gel fireplaces burn canisters of odorless fuel. Consol, mantle and media center configurations are available for both types of fireplace heater.

Gas Heater
These heaters use gas (usually propane (LPG), natural gas, or kerosene) to fuel a flame, which heats the air around it. Gas heaters are considered a greener source of heat than electric heaters, and can cost significantly less to operate. But because gas heaters emit carbon monoxide, they must be used in well-ventilated spaces to prevent serious health consequences.

Hydronic Heater
An evolution of old cast-iron radiators, hydronic heaters use water or a similar heat transfer fluid as a primary heating element. Built-in hydronic heat systems pump water into baseboard heaters from a central boiler. Electric hydronic heaters each have their own heating element and liquid sealed inside the unit. They can be connected to the household wiring and thermostat, or can be portable units that plug into any wall socket.

Garage Heater
Heavy-duty heaters meant to warm garages, workshops, warehouses and other workspaces where insufficient or nonexistent insulation makes a more powerful heater necessary.

Halogen Heater
Halogen heaters use a variation of quartz heating elements that includes a small amount of halogen gas inside the quartz bulb to prolong the operational life of the unit. See quartz heaters below.

Infrared Heater
Infrared heaters are also called radiant heaters, and emit electromagnetic waves to transfer heat, just like the rays of the sun. Instead of heating the air in a room, an infrared heater provides direct heat to the objects it is pointed at. Unlike convection heaters, infrared heaters can keep people warm outdoors, and are ideal for open or poorly insulated industrial spaces.

Micathermic Heater
A micathermic heater has a heating element encased in thin sheets of mica, a kind of stone that is very conducive to heat. They are lightweight, easy to move, and usually come in an unobtrusive flat-panel design that can be wall mounted. The mica warms up quickly, so these heaters can swiftly heat a room. They also provide both radiant and convection heat, making them unique amongst heater types.

AH-410 Image1Oil-filled Radiator Heater
These electrically-powered heaters resemble old-fashioned radiators, with coiled fins that radiate heat through natural convection. A heating element warms a special, heat-conserving oil that circulates through the fins, transferring heat to through the metal into the air. The larger the surface area of the heater, the faster the room will heat. The oil is not burned as fuel, but used as a heat reservoir and never needs to be refilled.

Patio Heater
Radiant heaters designed to provide warmth in outdoor settings. The most familiar style is a tall column with an umbrella-like cap at the top to reflect heat onto the people below. Alternative configurations can be mounted on walls or patio coverings.

Portable heaters can come in many sizes and configurations, but what they all have in common is that they can be moved from location to location. Space heaters that must be wired into the electric system, connected to a fuel line, or installed with ventilation ducts are not portable.

Quartz Heater
Quartz bulbs are be used in electric infrared heaters to produce a particularly rapid heater response. The bulb is commonly a white or clear glass tube that encloses a heat-resistant filament, usually tungsten, and an inert gas such as nitrogen or argon. When the filament is heated by electricity, the temperature of the tube increases and radiates infrared rays. See also halogen heaters.

Radiant HeaterH4200S Image1
See infrared heaters.

Reflective Heater
Reflective heaters are infrared heaters with a reflective panel that helps to direct and magnify the electromagnetic rays, to increase heating performance.

Space Heater
Small, portable heaters designed to heat individual rooms or areas.

A control unit that senses temperature and maintains it at the setpoint by turning heating and cooling devices off and on.

Tip Over Switch
A common built-in safety device that deactivates a space heater if the unit is knocked askew, in order to prevent overheating and reduce the risk of fire.

The standard measurement of electrical force or pressure. In practical terms, it describes the force of energy that comes through an electrical outlet. Most standard outlets in the U.S. are rated at 120 volts, which is suitable for most space heaters. Larger units might require 240 volt outlets, however, and will not function in 120 volt outlets.

Wall Heater
Electric wall heaters provide heat to individual rooms without taking up any valuable floor space. Most can be recessed into the wall to keep it out of the way.

A watt is a unit of power equal to one joule of energy per second. The watts rating listed on an electric space heater tells you how many watts the unit needs to run at its maximum setting.

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