Central heating

Central heating
     A central heating system provides warmth to the whole interior of a building (or portion of a building) from one point to multiple rooms. When combined with other systems in order to control the building climate, the whole system may be a HVAC (heating, ventilation and air conditioning) system.
     Central heating differs from local heating in that the heat generation occurs in one place, such as a furnace room in a house or a mechanical room in a large building (though not necessarily at the "central" geometric point). The most common method of heat generation involves the combustion of fossil fuel in a furnace or boiler. The resultant heat then gets distributed: typically by forced-air through ductwork, by water circulating through pipes, or by steam fed through pipes. Increasingly, buildings utilize solar-powered heat sources, in which case the distribution system normally uses water circulation.
      In much of northern Europe and in urban portions of Russia, where people seldom require air conditioning in homes due to the temperate climate, most new housing comes with central heating installed. Such areas normally use gas heaters, district heating, or oil-fired systems. In the western and southern United States natural-gas-fired central forced-air systems occur most commonly; these systems and central-boiler systems both occur in the far northern regions of the USA. Steam-heating systems, fired by coal, oil or gas, feature in the USA, Russia and Europe: primarily for larger buildings. Electrical heating systems occur less commonly and are only practical with low cost electricity or when geothermal heat pumps are used. Considering the combined system of central generating plant and electric resistance heating, the overall efficiency will be less than for direct use of fossil fuel for space heating.

NewAir AH-450 Electric Oil-filled Radiator Space Heater With Programmable Thermostat

Get the benefits of a portable heater with the classic styling of oil filled heating with the NewAir AH-450 electric oil filled space heater. This heater offers even, consistent heat and provides the ultimate in convenience and portability.
Produces Gentle, Safe Heat
Featuring a gentle rounded design and a fully-enclosed heating element that safely heats a special diathermic oil stored internally, the NewAir AH-450 provides gentle heat without any odors or fumes.
Greater Heat Output
The permanently sealed oil reservoir never needs to be refilled or replaced, while the vertical thermal slots result in faster air circulation and greater heat output.
Easy to Transport
Four sturdy, easy glide casters and a convenient carrying handle also make this heater easy to move from room to room.
Additional Features
Other great features include a built-in 8-hour timer, LED controls, and a programmable electronic thermostat that monitors your room's temperature to conserve energy and ensure constant comfort. To ensure user safety, the AH-450 space heater has overheat protection and a tip-over switch. See more details

Residential Energy Efficiency - Space Heaters

Residential Energy Efficiency - Space Heaters
     Heating cold areas of your home, noticeably increasing the warmth in one area, or to save energy are several reasons you might choose to use a space heater.
If you turn your central heating system down a few degrees and supplement the heat in a small area with a space heater, you will probably save money. If you do not turn the thermostat down and add more heat with the electric space heater, you will increase your total bill.
Get the Right Space Heater for Your Needs
     Electric, gas, or wood heating appliances can be used for space heating. However, the most common form of space heater is electric because it is portable and convenient. Electric resistance heaters are the most expensive form of heating so consider other forms of space heating for more permanent situations. Below is a list of different types of electric space heaters that are especially suited to specific situations.
For constant usage, a radiator-type heater provides even warmth and a safe source of heat for limited areas. A good application would be any room in constant use that you want to maintain slightly warmer than the rest of the house. This type of heater would not be a good choice for quick warm-ups. The surface of this type of heater is not as hot as other types of heaters. With proper use, it should be safer with respect to causing burns or fires.
     For heating an area quickly, a convection heater with a ribbon or wire heating element is best. A fan will help move the heat away from the heat source. Uses for these heaters would be in bathrooms, workshops, and seldom-used areas. This type of heater gets hot enough to cause a fire or severe burn.
For spot heating, a radiant heater will warm objects or people in its path. They provide warmth almost instantly to objects, but they heat a room slowly. Examples of usage for this type of heater would be for a person at a workbench, in a chair or at a sewing machine. This type of heater gets hot enough to cause a fire or severe burn.

Cost to Operate
     The cost to operate a space heater will vary depending on the type of space heater you use and the room you are heating. A good general formula for calculating cost is Kilowatts x Rate x Time = Cost.

• Kilowatts - Setting the heater will run on. (Divide watts by 1,000 to get Kilowatts per hour.)
• Rate - The cost of electricity per kilowatt hour. This can be determined for your area by contacting your utility company.
• Time - Amount of time you will be running the heater.

For example, a 1,500 watt space heater running for 10 hours at a rate of $.10 per kilowatt hour will cost $1.50.

Kilowatts	x	Rate	x	Time	=	Cost
(1,500w/1,000)	x	.10 kWh	x	10 hours	=	$1.50

Efficiency

     All electric resistance heaters are considered 100 percent efficient because there is no heat loss through ducts or combustion. Remember that some space heaters deliver heat more quickly or more concentrated than others. Also, using electric resistant heat to heat the entire house is generally more expensive than using other systems like a natural gas furnace or a heat pump.
Safety
     Contact with the heating element in an electric heater can cause fabric to catch fire or can burn the skin. Install fire detectors in the rooms where space heaters will be used.
Space heaters can overload your electrical circuits. If a fuse blows or breaker trips, you have overloaded that circuit and need to contact your electrician.
Never use an electric heater with a common household extension cord.
Energy-Savings Measures
     Before investing in a space heater, here are a few energy-saving measures. Weatherizing your home by installing caulking and weatherstripping around doors and windows will help to eliminate air leaks. Also, clean or replace your furnace air filter on a regular schedule.

Space heater

Space heater
     A space heater is a self-contained device for heating an enclosed area.[1] Space heating is generally employed to warm a small space, and is usually held in contrast with central heating, which warms many connected spaces at once. Space heaters are usually portable or wall-mounted, and may use natural gas or propane, but are most commonly electric

Types of heating
     Space heaters can be divided into those that transfer their heat primarily by convection, or by radiation.
Convective heaters
     In convection heaters, heating elements either warm the air directly or heat oil or another filler, which in turn transfers heat to the air. The air then warms the objects and people in the space. Convective heaters are suitable for providing constant, diffuse heat in well-insulated rooms. Oil heaters warm up slowly but do not reach dangerous surface temperatures; wire-element heaters, which may be fan assisted, reach operating temperature much more quickly but may pose a fire hazard.
Radiative heaters
     Halogen heaters usually comprise tungsten filaments in heat-resistant quartz envelopes, mounted in front of a metal reflector in a plastic case. They operate much like halogen light-bulbs, but radiate their energy primarily in the infrared spectrum. They convert up to 86% of their input power to radiant energy, losing the remainder to conductive and convective heat. The advantage of halogen heaters is that the radiation they produce is absorbed directly by clothing and skin, without first heating the air in the space. This makes them suitable for warming people in poorly-insulated rooms, or even outdoors.

Power Sources
Electric heaters
An electric fan heater.
     Modern electric space heaters may have ceramic or nichrome heating elements, and may be fan-forced with a blower or a squirrel-cage fan to improve heat transfer. Window or wall-mounted units, often seen in hotel rooms, are permanent space heaters. These often employ efficient heat pumps, which use reverse-cycle air conditioning to transfer heat to the inside from the outside.
Gas heaters
     Gas heaters use propane, butane, or liquefied petroleum gas. They may be convective or radiative, in the latter case by heating a matrix which then emits infra-red radiation. Gas heaters burn their fuel in air and produce carbon dioxide. In well-insulated rooms the oxygen concentration may drop and carbon monoxide may accumulate to toxic levels due to incomplete combustion. For this reason gas heaters should be used only in rooms with adequate ventilation. When used outdoors, for example as patio heaters, they present the dual advantage of portability and higher output (due to not being constrained by the current-carrying capacity of electrical wiring).
Kerosene heaters
     A Japanese space heater that burns kerosene for fuel. It contains an electric fan and computer controls.
Kerosene heaters were once common, and are still widely used in some regions. Paraffin is used to heat many informal dwellings in South Africa, where it poses a risk of fire and carbon monoxide poisoning.
Safety issues
     The two primary health risks from heaters are the risk of fire, and the risk of carbon monoxide poisoning. The latter risk accompanies gas and kerosene heaters but not electric ones. The risk of fire from electric heaters may be mitigated by low surface temperatures (as found on oil-filled convective heaters), or by switches that cut power in the event of the device being knocked over (often found in the bases of halogen heaters), or by thermal cut-out switches. The EPA does not consider space heaters as an Energy Star-qualified product.