Can you use a space heater as a heat source for your sauna? Yes! In this article, I am going to tell you exactly what you have to do and what you should consider.
Quick answer: Yes, you can use space heaters to heat a sauna. However, you either have to use two electric space heaters without built-in thermostats simultaneously or one propane gas heater for heating. Adding insulation to your sauna helps increase to raise the possible maximum temperature.
Let’s first see how much heat a sauna needs and whether we can get that heat from regular space heaters. Later we’ll check which space heaters are suitable for heating a sauna.
How much heat do saunas need?
To get a sauna up to temperature, you need at least 2,500W of heating power. Now, for very small one-person saunas, you might need less, but let’s focus on saunas for 2 or more people.
A sauna needs to be heated to around 180°F. Here’s how much heating power you need to get your sauna to that level:
| Sauna Size | Required heat |
| Small (2 – 3 people) | 2,500W |
| Medium (4 – 5 people) | 3,500W |
| Large (5+ people) | 4,500W |
What are the limitations of using a space heater for a sauna?
So, before we look at the steps to heat your sauna using space heaters, let’s have a look at some limitations. Based on these, we will figure out how to heat a sauna properly.
#1 Limitation: Space heater power consumption
The first limitation is that most electric space heaters in the US produce a maximum of 1,500W of power.
That’s below the required heating powers from the table. So, you can’t expect to heat a decently sized sauna with just one electric space heater.
#2 Limitation: Household electric circuit power capacity
The second limitation is that US household circuit breakers will trip at either 15 Amps or 20 Amps.
With a voltage of 120V, the maximum power consumption of a household circuit is
15A × 120V = 1800W
or
20A × 120V = 2400W
So, most space heaters are designed to run on 1,500W maximum power to ensure that they never trip a circuit breaker or blow a fuse.
In European and UK households, you can draw a lot more! There, the wall outlet voltage is 230V, causing the maximum power consumption to be
15A × 230V = 3450W
or
20A × 230V = 4600W
This means:
In the US, you can’t run two electric space heaters on full power settings at once. So, you can’t use electric space heaters to heat a sauna. In Europe and in the UK, you can.
#3 Limitation: Space heaters cut off heating
The third limitation is that most electric space heaters have a built-in thermostat. The thermostat is actually a good thing.
When used in a regular room heating setting, the thermostat ensures that the space heater heats your room to the set temperature and it won’t overheat.
However, in a sauna, you want your space heater to not cut-off heating anywhere below sauna temperature.
We can conclude:
To heat a sauna using a space heater you need a heater that does not have a built-in thermostat and does not cut off the heating. Also, you need a heater that does not overload your home’s electric circuit.
Which space heater can you use for a sauna?
As we’ve learned from the previous section, for heating a sauna, your home’s electric grid overloads if you attach two space heaters simultaneously. Also, most electric space heaters have a built-in thermostat.
Therefore, electric space heaters are not an option for heating a sauna. You can use an electric space heater in combination with another non-electric space heater or sauna heater to reduce the sauna’s heat-up time.
Electric space heaters are only suitable for supplementary heat.
To heat a sauna, you should get a propane heater.
Propane heaters do not cut off the heating at a certain temperature as they don’t have a built-in thermostat.
Also, propane heaters can output much more heat than any regular electric space heater.
A propane heater that outputs 18,000 BTU of power produces heat equivalent to 5,274W.
( One BTU equals 0.293W )
This means one propane heater produces more heat than three regular 1,500W electric space heaters.
Recommended propane heater for sauna
For heating a 2-5 person sauna, I recommend this Mr. Heater Big Buddy (click here to see my review).
This model provides 18,000 BTU of heating power, which is enough for most regular-sized home saunas.
There are even stronger propane heaters, but these are usually tank-top mounted, so they are not suitable for usage in a sauna.
This recommended model can be hooked up to a propane tank via a hose that you can run through your sauna’s walls.
For heating large 6+ person saunas, I recommend getting two of those heaters.
How to heat a sauna using a propane heater
To heat your sauna using a propane heater, you should do the following things:
#1 Setup the heater through the sauna’s walls
When using a propane heater, the propane tank should ideally stay at room temperature.
You should never place a propane tank in a sauna.
To do that, place your propane heater inside the sauna, and use a hose to connect the heater to the propane tank.
With most saunas, that’s pretty simple to do since they have pre-drilled air vents in which you can put the hose.
#2 Insulate your sauna well
Space heaters don’t provide as much heat as a fully-sized sauna stove. So, you should insulate the walls of your sauna well.
You can, for example, add an additional layer of styrofoam to the sauna’s roof.
Just make sure that any flammable insulation material is not exposed to your propane space heater’s burning-hot heating elements.
#3 Build a heat reflector
Propane heaters are usually very directional. If you place your propane heater on the floor, then it will radiate a lot of heat toward your feet, which you probably don’t want.
You can build a heat-reflector construction made of aluminum (or other metal) sheets, which you place in front of your propane heater. The construction should reflect the heat toward your sauna guest’s bodies.
Just make sure that your construction does not overheat your propane heater by reflecting heat back at the heater.
How to use an electric space heater for a sauna?
You can’t use most electric space heaters for a sauna, because they provide too little heat.
However, if you don’t like too hot saunas and prefer temperatures around 140°F, then you can use your electric space heater for that.
You will need a small 1-3 person sauna and run your space heater at full power inside. It should be a space heater that does not cut off temperature using a thermostat.
Unfortunately, it’s very hard to find these “insecure” space heaters.
You might have a good chance of finding old, used models with lower safety standards on eBay.
But in general, I don’t recommend using electric space heaters for saunas. Electric space heaters are just not designed to power a sauna, even if it’s a small one.
Can you speed up sauna heating using electric space heaters?
Yes, you can speed up your sauna’s heat-up time using a space heater. However, above 100°F electric space heaters won’t heat due to their built-in thermostat.
Additionally, you will have to remove your space heater when your sauna gets too hot to protect it from damage.
Saunas take a long time to heat up. A large part of the heat-up time is consumed to raise the temperature of the solid objects in your sauna, e.g. the wood, the insulation, and any metal or glass parts.
The air in your sauna only takes little time to heat up.
So, to speed up your sauna heat-up time, you can use a space heater. The space heater will increase total heating power working on heating the sauna up.
Additionally, if you have an infrared heater or a blowing heater (or any kind of heater that directs the heat), you can point it at the largest, most massive object in your sauna.
The largest objects are usually the things determining the general heat-up time of your sauna.
I think using an electric space heater to speed up your sauna’s heat-up time introduces too much hassle.
You will have to set it up in addition to your sauna heater, you have to remember to remove your space heater in time, and likely, it won’t change the heat-up time of your sauna that much.
So, it’s not worth it.
Conclusion
To heat a sauna using a space heater, you should use a propane heater. Propane heaters work independently of your home’s electric grid and provide much more heat than regular electric heaters.
If you live in the UK or Europe, you can also use two electric space heaters simultaneously, as UK and European electric circuits support more power than in the US.