Propane heaters offer an efficient and affordable way to heat homes and indoor spaces, so why are they not used more often? Sure, you may have used propane to fire up your grill or heat your pool but the thought of using a propane heater indoors can be a little daunting.
Well, we’re here to bust some myths around propane heaters to help you understand how to use this alternative fuel safely, along with outlining some of the benefits of doing so.
Can you use propane heaters indoors?

The simple answer is YES! However, you must ensure you’re using the correct type of heater. Propane heaters come in two different versions: one suitable for indoor use and one for outdoors. It goes without saying that for indoor use, you should check you’re using a propane heater indoors that’s been designed for indoor use only.
The difference between indoor and outdoor propane heaters
All propane heaters work by burning liquid propane, and this process creates gas. This gas is dealt with differently by indoor and outdoor heater models. A propane heater that has been designed for outdoor use only will burn fuel at a very high rate and produce much more combustion gas than indoor-safe propane heaters, this gas may contain carbon monoxide which can cause carbon monoxide poisoning if left to accumulate in enclosed spaces. Outdoor use propane heaters should be positioned in well-ventilated areas.
A propane heater indoors is a different thing and has been specifically designed for use in enclosed spaces and usually come with a host of additional safety features such as automatic shut-off switches, high temperature coated safety guards and carbon monoxide detectors.
A few facts about indoor safe propane heaters
Used correctly, propane heater indoors is designed to heat spaces faster and more efficiently than more traditional heating sources, which can result in lower energy costs. It’s a little-known fact that over two-thirds of the energy used to get electricity into our homes is wasted in the process, but modern propane heaters are up to 98% efficient, losing less than 10% of fuel in the combustion process. Neat, huh?
Some other benefits include:
- Propane is a clean-burning fuel and therefore a propane heater indoors requires very little in the way of ongoing maintenance
- Indoor-safe propane heaters are pretty robust and generally last much longer than other electric appliances
- Whilst propane is a gas, it is not considered a greenhouse gas and is therefore not harmful to the environment
- The price of propane is generally lower than other energy sources and better yet, propane heating systems run much warmer and at a fraction of the cost.
What kind of ventilation do you need for a propane heater indoors?
Before considering the kind of ventilation that might be needed when using a propane heater indoors, you must first establish whether you’ll be using a vent-free or a direct vented heater.
Vent-free propane heaters
These heaters need no additional vents to provide heat making them a cost-effective heating system to install. You must ensure that there is enough air circulating into the heated space which can be as simple as opening the window or the door (this will not affect the efficiency of the heater). The heater should be positioned facing the part of the room that needs the most heat, but away from flammable or combustible items of furniture.
Direct Vent Propane Heaters
These self-contained heaters make use of outside air to generate heat within a combustion box. All resulting gases are then released directly back outside via a small pipe that must be inserted through an exterior wall. They don’t need a chimney and can be mounted on almost any exterior wall. Most direct vent propane heaters use gravity to circulate warm air, but some make use of a fan. Whether using a direct vent or vent-free propane heater it would be wise to invest in a carbon monoxide alarm for your safety and always read the manufacturer’s instructions. These are not designed to be a ‘do it yourself project and should be installed by a propane heating specialist.
What size propane heater do I need?
Propane heaters come in a variety of different sizes, and you should only use one that’s the right size for your room. Propane heaters are measured in BTUs (British Thermal Units) and this measurement tells us how much heat will be needed to change the temperature of a specific area. 1 BTU is roughly equivalent to burning a match.
There are several informative resources online to help you calculate the size of the heater needed for your room, such as this article from Amerigas.
Carbon monoxide poisoning and propane heaters
Carbon Monoxide is a colorless, odorless, tasteless poisonous gas that is produced by the incomplete burning of carbon-based fuels. When carbon monoxide enters the body, it stops the blood from delivering oxygen to cells, tissues, and organs and can be fatal.
Propane heaters that have been used correctly and maintained regularly pose no risk of carbon monoxide poisoning. However, they should be inspected and serviced at least once a year by a specialist. You should also never use a propane heating system that has been designed for outdoor use (such as an outdoor grill or heater) to heat an indoor space as you will be unable to ventilate the room properly.
A propane heater indoors is supplied with automatic shut-off switches that are connected to oxygen sensors – at the point there is not enough oxygen in the room, the heater will shut off automatically. This helps prevent carbon monoxide from building up to dangerous levels.
Carbon monoxide detectors ensure an added layer of security and should be placed several feet away from the heater. By keeping the detector and the heater a good distance away from each other you are more likely to get an accurate carbon monoxide reading. If the carbon monoxide levels in the room reach anything close to dangerous levels, the alarm will alert you.
Does opening a window stop carbon monoxide?
It feels counter-intuitive to leave a window open when you’re trying to heat up a room, but it’s a good way to reduce any risk of carbon monoxide. Leaving a window open even just a few small inches will provide a vent and help to prevent a dangerous build-up of gas. You will retain much more heat than you’ll lose and will provide peace of mind.
Propane heater safety tips
Using a propane heater indoors has a remarkable safety record, in the most part down to the tight safety codes and industry regulations that have been developed over recent years. However, it is always better to be safe than sorry, and these propane heater safety tips will help keep you and your family safe whenever you run a propane heater indoors.
- Turn off the heater if you smell anything unusual – Whilst carbon monoxide is odorless and tasteless, propane isn’t. Propane manufacturers add a strange smell to the gas which helps people detect when there is a leak. If you smell anything strange when using a propane heater indoors you must turn it off immediately before opening the windows to inspect the system. Call a professional to check the heater if you have any concerns whatsoever.
- Never leave a propane heater unattended – Whether using a propane heater indoors or outdoors, you should never ever leave it unattended. Children, pets, strong gusts of wind – these could all knock over your heater, creating a risk of fire or fuel leaks. Always switch propane heaters off before going to bed
- Do not try to move the heater whilst it is switched on – a propane heater indoors will throw out an incredible amount of heat and could cause a serious injury to you if you try to move or handle it whilst it is switched on. If you need to move it, turn it off and wait for it to cool before handling it
As you now will have discovered, a propane heater indoors can be an effective, efficient, cost-effective, and environmentally friendly heating source for your home, BUT care must be taken to ensure they’re being used safely.
By taking the time to understand the different types and the best ways to use them, you can be sure of a warm and welcoming home for several years to come from a propane heater indoors.
Frequently asked questions
Can you get carbon monoxide poisoning from a propane heater indoors?
Whilst propane heaters can produce carbon monoxide, properly functioning appliances produce very little or no carbon monoxide. However, you should only use propane heaters that are suitable for indoor use in enclosed spaces and keep rooms well ventilated if using vent-free propane heaters indoors.
Is it safe to use a propane heater indoors?
Yes, it is very safe to use a propane heater inside providing you take the time to research the different types of propane heaters, and only use one specifically designed for indoor use. In addition, you should follow safety guidelines and reduce any risks of carbon monoxide poisoning, such as installing a carbon monoxide detector.
How much ventilation does an indoor propane heater need?
Indoor safe heating solutions such as vent-free and direct vent propane heaters require different kinds of ventilation. Vent-free heaters must only be used in well-ventilated rooms, with a window or door open to allow oxygen to circulate in the room.
Direct vent propane heaters must be installed by a regulated propane heating specialist and release gases outside via a small pipe that goes through an exterior wall.
Is it safe to heat a garage with propane?
Propane heaters are a fantastic option for heating garages as they’re less expensive to run than electric garage heaters. Keeping the garage door open as this will provide plenty of ventilation for most propane heaters but if you are planning to keep the garage door closed, you must follow the advice for using a propane heater indoors.