Space Heater vs Central Heating: Which Costs Less?

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Is a space heater cheaper than central heating? Sometimes—but not automatically. The answer depends on what your central heating system uses, how many rooms you need to heat, your local energy prices, your home’s insulation and whether the portable heater allows you to reduce the rest of the home’s heating load.

Quick answer

A space heater can make financial sense when you heat one occupied room and turn down the central system elsewhere.

It is less likely to save money when you run the space heater while keeping the entire home at the same central-heating setting. In that case, you are usually adding another heating load rather than replacing one.

The key question: what type of central heating do you have?

Heat pump

If your home uses an efficient heat pump, an electric resistance space heater may use more electricity to deliver the same amount of useful heat. Heat pumps move heat rather than generating all of it through resistance.

The U.S. Department of Energy says today’s heat pumps can reduce electricity use for heating by up to 75% compared with electric resistance heating such as furnaces and baseboard heaters.

Source: U.S. Department of Energy — Heat Pump Systems.

Electric resistance furnace or baseboard heating

If both systems use electric resistance, the basic conversion of electricity to heat at the point of use is similar. The savings opportunity comes mainly from heating a smaller area, not from a portable heater being magically more efficient.

For example, a 1200W heater in one office may use less total energy than keeping several unused rooms warm—if you actually lower the larger system.

Gas furnace

With natural gas, you must compare your gas rate, furnace efficiency and distribution losses with the electricity rate for the space heater. A portable electric heater is not guaranteed to be cheaper simply because it heats a smaller area.

Boiler or other system

Boilers, hydronic systems and other central systems can have very different fuel costs and efficiencies. Compare actual energy prices and system performance rather than using one general rule.

When a space heater can cost less

A portable heater is most likely to reduce total cost when all of these are true:

• You spend most of your time in one room.
• You can safely reduce the thermostat for the rest of the home.
• The room can be closed off or retains heat reasonably well.
• The central system would otherwise heat a much larger area.
• The portable heater runs only as long as needed.

This is often called zone heating: putting heat where the person is rather than maintaining the same temperature everywhere.

When a space heater may cost more

• You keep the central thermostat unchanged.
• You run several space heaters in different rooms.
• You use the portable heater for very long periods every day.
• Your central system is an efficient heat pump.
• Your electricity rate is high compared with your central-heating fuel.
• The room is very drafty or poorly insulated.

Example using a 1200W heater

A 1200W space heater uses 1.2kWh for each hour it runs continuously at full power.

At $0.20/kWh:

• 1 hour = $0.24
• 4 hours = $0.96
• 8 hours = $1.92
• 8 hours/day for 30 days = $57.60

Use our 1200W space heater cost guide for more electricity-rate examples.

Why “100% efficient” can be misleading

Electric resistance heaters are often described as effectively converting their electrical input into heat at the point of use. That does not mean they are automatically the cheapest heating technology.

A heat pump can deliver more heat to the room per unit of electricity because it transfers heat from outside rather than generating all of it through electrical resistance. Cost also depends on the price of electricity compared with gas or other fuels.

What about Hexa Heat?

The current Hexa Heat merchant documentation lists a maximum power draw of about 1200W. That makes it suitable for the same running-cost calculation above.

If you use Hexa Heat in one office while turning down a larger central system, it may reduce total heating use in some homes. If you leave the central thermostat unchanged, the portable heater simply adds up to 1200W of extra electrical demand while its heating element is running.

Read our Hexa Heat portable heater review for the product-specific details.

Does closing the room matter?

Yes. Zone heating works better when the room holds heat reasonably well. A heater in a room with open doors, large drafts, poor insulation or frequent traffic has to replace heat that continually escapes.

However, do not block required ventilation or use the heater in a location prohibited by its instructions.

Should you turn central heat completely off?

Not necessarily. In cold climates, turning central heating off entirely can create comfort, moisture or frozen-pipe risks. A more practical strategy may be to lower the whole-home thermostat and use targeted heat in the occupied room.

The appropriate minimum temperature depends on your home, climate and plumbing, so there is no single safe setting for every property.

Space heater safety still matters

Any cost saving is irrelevant if the heater is used unsafely. The U.S. Consumer Product Safety Commission recommends keeping portable heaters at least three feet from bedding, furniture, curtains and other combustible materials.

CPSC also advises plugging electric space heaters directly into a wall outlet rather than a power strip or extension cord and turning them off while sleeping.

Source: CPSC portable-heater safety guidance.

Which option is cheaper for one room?

If heating one room allows you to turn down a central system serving the entire home, the space heater can be the lower-cost option overall.

If the central system is an efficient heat pump already heating the occupied zone effectively, a resistance space heater may use more electricity for the heat it supplies.

Which option is cheaper for the whole house?

A portable space heater is generally not designed as the most economical way to heat an entire home. Multiple portable heaters can quickly add up to several kilowatts of electrical load and introduce additional safety and outlet-loading concerns.

Whole-home heating should be compared using the efficiency, capacity and fuel price of the installed system.

A simple decision framework

• One person, one room: a space heater may make sense if you reduce central heating elsewhere.
• Several occupied rooms: central heating may be more practical.
• Efficient heat pump: compare carefully before substituting resistance heat.
• Electric resistance central heat: savings depend mostly on reducing the heated area.
• Gas or boiler system: compare actual gas/fuel and electricity prices.

Current portable-heater examples

For product-specific research, see our Hexa Heat review, Top Heat review, and Hexa Heat vs Top Heat comparison.

Bottom line

A space heater can cost less than central heating when it lets you heat one occupied room instead of a much larger area. It does not automatically save money just because it is small or portable.

The most important comparison is your existing central system, local energy prices and whether you will actually reduce the central-heating load.

For product selection, see our portable heater safety and buying guide. For a concrete running-cost example, see how much a 1200W heater costs to run.