Supplemental Heaters

A space heater is the answer to those chilly days or evenings in spring or fall when it is not cold enough to start the furnace. It can also be used in extremely cold weather to raise the temperature of one room to a comfortable level while "dialing down" the remainder of the house.

Portable heaters are excellent in emergencies when a furnace breaks down or there is an interruption in gas or electrical service.

For maximum results, place the heater under a window to warm cold air as it enters the room, whether through an ill-fitting window frame or just off the cold glass.

ELECTRIC HEATERS

Electric heaters should, if possible, be plugged directly into the wall outlet; if an extension cord is necessary, it must be heavy duty (14 gauge wire).

Heating elements are so-called "black heat" with the heating wire wound around porcelain insulators or the more popular "instant heat" that utilizes a ribbon element.

Heating capacity is rated in BTUs (British Thermal Units). Wattage ratings of heaters can be converted to BTUs consumed per hour by multiplying the number of watts by 3.413 (the number of BTUs equaling one watt).

For example, a heater with three heat selections of 1,000, 1,320 or 1,650 watts will have BTU outputs of 3,413, 4,505 and 5,631, respectively.

Most better electric heaters feature a tip over safety switch, which shuts the heater off automatically if it is knocked over.

Some models come equipped with a thermostat, and some have small fans to force heated air into the open room.

RADIANT HEATERS

Unlike traditional convection heating systems that warm the air in a room which then warms its objects and occupants, radiant heaters bombard objects directly with heat. This is how quartz heaters and infrared heaters work.

All have as their main selling feature that they direct heat to the objects or people to be warmed. For short periods of time (two to three hours), these heaters are more energy efficient than convection heaters.

These heaters usually have a wattage rating of 1,500. The heating element, encased in quartz or a metal sheath, has a reflector panel behind it to direct the heat toward the objects. Some models will cycle off and on, but none have a thermostat.

These heaters should have a tip over device to automatically shut the heater off should it be tipped over.

Periodically the quartz rods will need to be replaced. This can be done easily by snapping in a replacement rod.

KEROSENE HEATERS

Many residential kerosene heaters eliminate the need for a pressure-fed fuel system by using a wick, which is a safety feature. In addition, safe units offer automatic shutoff devices to extinguish the flame if the heating unit is bumped or jarred, and grilles or guards to keep hands away from hot surfaces. Pushbutton, battery powered lighting devices that eliminate the need for matches are available on some models.

Approximately 28 BTUs/hr. are required to maintain one square foot of space at 70 degrees. Multiplying this figure by the total square footage of a room gives the approximate BTU rating a model should have to heat the room.

Use caution by using only K1 clear kerosene fuel. Fuel that is yellow or colored will smoke, smell and interfere with wick operation.

There has been widespread concern about the safety of kerosene heaters. Open-flame heaters such as kerosene heaters deplete oxygen in the air and discharge carbon monoxide. Consequently, some local ordinances ban the use of open-flame heaters. You should check with local government agencies to learn what restrictions, if any, exist on kerosene heater use.

Some safety tips from the National Kerosene Heater Association include:

• Never use gasoline which, even in small amounts, creates the risk of flare-up and fire.
• Add fuel to the heater or cartridge tank out of the living area in a well ventilated location.
• Never move, refuel or service the heater when it is operating or hot.
• Operate the heater only in well ventilated areas.
• Keep heater more than 3' from materials such as furniture, clothing and draperies and out of high traffic areas.
• Extinguish heater before sleeping.
• Follow state and local regulations.

CONVECTION HEATERS

A circular, hassock-shaped heater with no reflector warms the air which rises and is distributed around the room (convection). A natural convection heater with no fan is one of the safest to use around small children because elements are almost completely enclosed; however, it does not give off as much heat as other supplemental heaters.

Convection heaters with a reflector and one or more fans provide uniform warmth in a room and are much more effective.

BASEBOARD HEATERS

Baseboard heaters will warm a room well and have the added advantage of occupying unused space. Some have a fan.

Most radiant baseboard heaters incorporate a thermostat. Convection heaters and models without a thermostat usually have a choice of two or three settings. Protective grilles are removable to facilitate cleaning.

Grilles should have a close mesh, particularly if they are to be used around small children, who may be able to push small objects or their fingers through large meshed grille work.

GAS HEATERS

The popularity of natural and liquid propane (LP) gas space heaters continues to grow as consumers seek ways to trim their heating bills. Gas heaters have a high efficiency and low operating cost compared to similar electric and propane heaters.

Gas heaters are available in both vented and un-vented models. The traditional gas heaters for supplemental heat require outside vents. Most of these are available in medium or high output models that range from 25,000 to 65,000 BTUs/hr. Most of these also include enclosed "radiating circulator" units with tempered glass in front of a series of radiants. Generally, gas vented heaters are thermostat controlled. These heaters are designed to take up minimum space. Un-vented gas heaters are supplementary heat sources, since they require no vent. However, they must be used in a well ventilated area to cut the risk of carbon monoxide buildup. Consumers must strictly adhere to the manufacturer's safety instructions and to have the unit installed by a HVAC (Heating Ventilation and Air Conditioning) certified professional.

Infrared radiant and convection are the most popular gas heater variations.

The infrared radiant units transfer most of their heat through direct infrared radiation from the heater to the objects in the room. Most models feature ceramic radiants or panels that are positioned above the gas burner. Many of these units are open. The ignited gas gives off a bright orange glow that heats the room's occupants. The heater's radiant plaque is protected by a screen-like guard, but is not enclosed in the cabinet or behind glass.

Popular in Europe for years, un-vented or circulating convection heaters can be freestanding or mounted in a wall. This type of gas heater has burners enclosed within a painted or enameled sheet metal housing that has air openings on the top, front, and possibly, the sides. They circulate heated air, which makes them suited to heating larger areas to uniform temperatures.

Convection heaters work like a mini central heating system. Convection heaters first warm the air, which then warms the objects.

Natural and LP heaters are especially suited for zone heating, because they are clean burning, inexpensive to operate and many models require no venting. Radiant and blue-flame heaters lend themselves to do-it-yourself installation, requiring only a gas line into the room where the customer wants the heater to go. Virtually all gas heaters are equipped with an oxygen-depletion sensor (ODS). ODS is an automatic shutoff device that is activated if the air supply becomes inadequate. It is mandatory equipment for un-vented heating equipment as specified by federal and voluntary standards.

PORTABLE FORCED-AIR HEATERS

These heaters come in models that operate on fuel oil, kerosene or propane gas, and can supply from 35,000-600,000 BTUs. They are used in work areas, such as garages and barns.

Portable forced-air heaters use fuel and electricity to circulate hot air around the area to be heated. Models are equipped with air and fuel filters to block contaminants.

Safety features include automatic ignition systems and a flameout safety sensor, which turns the heater off in the event of loss of combustion or lack of fuel.

DUCT FANS

While not actually a source of supplemental heat, duct fans are designed to boost the flow of air from the central heating system to a hard to heat or cool section of a house. They overcome the added resistance in long duct runs, allowing warm or cool air to reach the "problem" room.

They are available in two types: a prop fan that fits totally inside the duct or a squirrel-cage fan with the motor mounted outside of the duct. Most models will produce around 200 cfm in 6" to 8" diameter ducts. Duct fans can be wired in series with the central furnace blower or operated by an auxiliary thermostat.

CERAMIC HEATERS

Ceramic heaters are small portable electric heaters that use a ceramic disk heating element. The heaters are ideal for spot heating because they are lightweight and easy to carry.

These ceramic heaters are safer than other alternative heating sources because they operate at temperatures below the combustion point of paper. Ceramic heaters also include a washable filter to reduce air pollutants.

OTHER HEATERS

Room heaters, floor furnaces and wall furnaces are other types of supplemental heat sources available to the consumer. These usually use gas (natural or LP), oil or kerosene as a heat source.

They differ from central heating systems in that they do not use a duct system to distribute heat; they are located in or near the room to be heated and most require little or no electricity.

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Check your state and local codes before starting any project. Follow all safety precautions. Information in this document has been furnished by the North American Retail Hardware Association (NRHA) and associated contributors. Every effort has been made to ensure accuracy and safety. Neither NRHA, any contributor nor the retailer can be held responsible for damages or injuries resulting from the use of the information in this document.