Do Space Heaters Save Money?

Do space heaters save you money? And if yes, how? Space heaters use a lot of electricity. Nevertheless, you can use them to increase your home’s heating efficiency.

In this article, we are going to cover how you can cut your heating bill using space heaters!

Quick answer: Space heaters save you at least $162 yearly if you reduce your central heater’s temperature by more than 8°F (4.4°C) and supply heat using two space heaters. If you use just one space heater to supply heat, your heating bill is reduced by at least $324 a year.

Let’s have a closer look and see how space heaters can save you money. Also, we’re going to look at different scenarios and see when heating with space heaters is worth it and when it isn’t!

Saving money using space heaters might sound impossible. Space heaters are known to consume a lot of electricity. Running an average 1500W space heater costs $54 if you use it for 8 hours every day (source).

Still, it is possible to save money using space heaters. Let’s have a look at how.

Central Heat: The Main Cause Of High Heating Bills

First off, we have to understand what causes high heating and utility bills.

The main source of a house’s heat is the central heating system. The central heating system can be based on oil, gas, wood, or electricity.

It does not really matter which of those resources you use in your home. Since the central heating system supplies heat for the entire house, it automatically is the biggest cost factor.

On your central heating system, you can set target temperatures for your home. The higher the temperature you set, the higher the resulting heating bill.

When does Central Heating make sense?

Almost everyone uses central heating as a sole source of heat. The central heating heats up the entire house. Of course, there are room-local heat sources such as radiators or air vents connected to the central heating system. You use these to adjust temperatures for individual rooms.

Central heating is only worth it if the house’s size suits the number of people living and moving inside.

Let me break this sentence down:

Your house has several rooms. The rooms should always be used. Unused rooms do not need to be heated as much. Also, people move around the house. Ideally, the central heating should keep frequented rooms warm while unused rooms stay cooler.

Central heating does not make sense if the house is too big for the number of people living inside, or if only a subset of rooms is used.

How to Save Central Heat Money Using Space Heaters

To save money using space heaters, turn down the central heating temperature settings and supply heat with space heaters only to the rooms you are using.

The advantage of this is that space heaters are portable. You can bring them with you anywhere you go. Or you can scatter them around the house.

Through proper space heater placement, you can also influence the heat flow and the direction of heat radiation. For example, by properly placing an infrared heater to face directly toward you, you increase the amount of heat that reaches your body.

In addition to being able to turn down central heat, properly placed space heaters improve the perceived heating efficiency of your home.

In comparison, by using the fixed wall radiators or air vents from your central heating system, you have no control over where the heat goes.

Let’s check how much money you can save using space heaters.

1. Reduce Central Heating Temperature

In this section, we are going to estimate how much money you can save by turning down central heat and supplying heat using space heaters!

To get the final result, we have to first find out how much money turning down central heating saves. Then we check how much running space heaters costs. And in the end, we check if turning down the central heat plus running a space heater is cheaper than running central heat alone.

How much money does reducing central heating save?

Let’s check how much heating a whole house using central heating on comfortable heat settings costs.

Because each home varies in size, I’ll use percentages first. Let’s assume that running a home on comfortable central heat settings corresponds to 100% cost.

According to WWF, reducing the central heating’s set temperature by just one degree Celsius cuts your heating bill by 10%. A temperature difference of 1°C corresponds to 1.8°F.

So, reducing your central heating by one degree Fahrenheit cuts your heating bill by 5.6%.

I’ll not take that number for granted, since it is published by WWF, which is an environmental protection organization, and therefore its research is biased toward exaggerating numbers.

According to energyhub.com, reducing your heating settings by 1 degree saves at least 3% on your heating bill.

Probably the reality is somewhere between 3 – 5.6%. 

Central heating savings calculated

Let’s technically estimate our own percentage as well just to make sure (skip this part if it’s too confusing). For our calculation, we need the heat capacity (CP or Cv) values of air.

“The nominal values used for air at 300 K are CP = 1.00 kJ/kg. K, Cv = 0.718 kJ/kg”

according to ohio.edu

That means to heat 1kg of air in a fixed volume environment (a room), you’d need around 1kJ of energy.

For wintertime, a good estimate could be that the temperature difference between outside and indoors is 20 Kelvin (around 20°C or 37°F).

Accordingly, without heating, your indoor space would be cold and you would need no energy.

To heat your space to a comfortable temperature in a perfectly insulated room you would need an energy of 20K × 1kJ/kg = 20kJ/kg. In comparison, heating it one Kelvin less, you would need only 19kJ/kg of energy. That’s a reduction of 5%.

Correspondingly, our own experiment’s result states that a reduction of 1°F cuts your heating bill by 2,8% in a perfectly sealed and insulated room.

In a real environment, however, rooms are not perfectly insulated and heat leaves the room. For each additional degree you heat, the temperature difference between inside and outside increases. The bigger this temperature gradient is, the more heat leaves the room.

Therefore, I assume the WWF estimate of 5.6%, even though it is double the theoretical value we calculated.

Example calculation: How much can you save by reducing central heating by 5 degrees?

By reducing a home’s central heating temperature by 5 degrees, you reduce your heating bill by 25.03%.

You can calculate this yourself using this formula:

1-1×(1-0.056)^5 = 0.2503

How much money does reducing central heating save?

Inflation drives prices quickly, so it’s very hard to find up-to-date numbers. 

According to a National Energy Assistance Director’s Association estimate, the average US family pays $1,202 on heating bills per year.

This average includes different heating resources such as natural gas, oil, electricity, or propane.

Heating oil is the most expensive of all and costs $2,115 a year. Meanwhile, natural gas is the cheapest and costs $952 a year.

Personally, I expect average US heating bills to be significantly higher than these official values. But let’s stick to them for now.

By reducing your central heater’s temperature by just 4°F, you can save up to $435.43 a year.

I’ve done the calculations for you:

According to the table above, you obviously save more, the more you decrease your central heating bill. However, at some point reducing the temperature stops making sense.

A temperature reduction of 16°F for example would be very uncomfortable. It might even harm your house by accelerating mold growth and moisture buildup.

However, the main message is that even slight decreases in temperature, such as 1°F, 2°F, or 4°F already significantly cut your heating bill!

2. Use Space Heaters to Supply Heat Where it’s Needed

This is where space heaters come into play. You can reduce your central heater’s temperature settings and supply heat using space heaters.

Since one 1,500W costs about $54 per month to run (for an average US electricity rate of 14 cents per kWh), we have to ensure that the savings are larger than the space heater expenses.

I’ve done the calculation for you. Here’s how many space heaters you can run for the 3 cold winter months for 8 hours every day:

The average central heating bill savings come from combining the minimum and maximum values from the previous table. The rightmost column tells you how many space heaters you can run based on those savings.

If you run the listed amount of space heaters in your home, then you break even and have the same total expenses as running the central heating alone.

However, for each space heater that you spare, you save $54 × 3 winter months = $162.

And here it starts getting interesting:

Space heaters will only save you money if you reduce your central heating’s temperature by more than 8°F (or 4.4°C) and use 2 or fewer space heaters to supply heat in your home.

Using Space Heaters to Save Money: When does it make sense?

It can make sense to save money using space heaters if you are a very comfortable person and you have set a high central heating temperature.

Then, reducing by 8°F and supplementing heat where needed is not an issue.

However, saving money using space heaters does not make sense if your central heating is already set to a low temperature.

Then, an additional 8°F reduction gets uncomfortable quickly and enhances mold growth in your home.

Always make sure to keep your home at 64°F or higher. Don’t reduce your central heating settings below that.

This means you can only really save money using space heaters if your home’s central heating temperature setting is currently set to 72°F or higher.

If your central heat settings are below that, then the savings are not sufficient for running a space heater.

Other Highly Effective Ways to Save Heating Costs

Before trying to save money on your heating bill using space heaters, there are other optimizations you should check.

1. Improve your house’s insulation

First of all, make sure your home is well-insulated. A well-insulated home not only keeps the warmth for much longer. It also takes less heat energy and, therefore, also less money to raise your room temperature.

Insulation is the most cost-effective way to keep your house warm. The main benefit is that it is a one-off task.

Improve insulation once and it will reduce your heating bills forever. Additionally, insulation is maintenance-free. There are no moving parts, nothing that can break. And usually, it is very doable for most handymen.

2. Insulate your attic

The one insulation that is oftentimes overlooked is attic insulation. The attic specifically loses a lot of heat in the wintertime as the heat from your living space rises upward and, therefore, always passes through the attic.

An insulated roof and attic keep warm air in the wintertime.

Also, attic insulation is one of the cheapest forms of insulation, because it does not have to look good! It’s your attic. Just place styrofoam along the attic floor and attach a layer below the roof and you’re done.

In addition to keeping the heat in the wintertime, attic and roof insulation hold the cold air in the summertime and prevent your house from heating up. This additionally reduced your air conditioning electricity costs in the summertime.

3. Improvised insulation

If you don’t have the opportunity or funds to insulate your home’s walls, attic, and roof, you can still do something.

Especially when supplying heat using space heaters, you can block the airways below doors. Most of the heat in your room leaves through door gaps.

Just put a blanket in front of your door gaps and you’ve significantly improved your room’s insulation for free!

Of course, make sure to vent your room occasionally to get some fresh air. I am doing this very thing right now!

Conclusion

Space heaters can save you money if you reduce your central heater’s settings by around 8°F or more and supply heat using space heaters where you need it.

If you can’t reduce your central heater’s settings that much because of elderly people or a family in your house, saving money with space heaters is hardly possible.

Without reducing your central heating settings significantly, space heaters are usually just an additional expense.

But they can be worth it for quick heat or in rooms where your central heat does not work properly!