Does A Propane Garage Heater Need To Be Vented?

Most people choose a propane garage heater because it’s much less expensive than an electric heater. They are also relatively easy to install and, if taken care of properly, easy to use. But many wonder if propane garage heaters are safe. And do they need to be vented?

A propane garage heater absolutely needs to have ventilation. Propane uses the exact same oxygen that you use to breathe. You risk carbon monoxide poisoning when a propane heater is not properly vented. It also requires close monitoring to ensure that it is not leaking. 

Understanding how propane garage heaters work is the best way to feel comfortable with having one. This includes being familiar with its different parts and what it should look like when it is running safely. By the end, you will feel confident in running one in your garage. 

How Do Propane Garage Heaters Work? 

Indoor propane heaters use gas rather than electricity to heat an area with blowers. Most of the time, they are portable, which means they can be moved around. Many come with a thermostat and can be ignited automatically or manually, depending on the machine. 

Propane Fuel 

Propane is a combustible colorless gas that is usually stored in liquid form. Typically, garage heaters are stored in a pressure tank within the heater. The fuel is lit by the igniter and turned into gas to give off heat to fill the space. The heater will have some sort of material to evenly distribute the heat from the machine. This is usually porcelain. 

Propane Fuel 


  • A relatively affordable way to heat your garage
  • Easy to install 
  • Safe as long as it is taken care of properly


  • Propane is combustible, so caution is always recommended
  • Risk of carbon monoxide poisoning without proper ventilation


The propane heater starts the flame with the igniter. It usually uses a piezoelectric igniter. It produces an electrical discharge to light the flame. The igniter is one of the most critical parts of the system because it lights the pilot light. Most people realize their igniter is broken when they can light the heater with a match flame. 


The igniter is usually located near a v-shaped bracket around the gas port. The gas port often hooks right into the furnace or heater in some cases to supply the propane. 

Heat Distribution 

The heat gets distributed with a blower so that the flame disperses throughout the garage. It is often a porcelain element that helps evenly spread the heat out in patterns. In some cases, the propane heater may have a built-in fan to blow the heat out more effectively to fill the room. 

In these cases where an electrical component is involved, they will need an outlet to be plugged in, not for the heat but for the fan purpose. 

Safety With Propane Heaters

A propane heater comes with some safety precautions. The threat of carbon monoxide and fire is present without proper ventilation. Propane is combustible, which means that it can catch fire and explode. Understanding the safety measures one needs to take with a propane heater is critical to the household. 

Carbon Monoxide 

Carbon monoxide happens when propane is not correctly vented and is left without the necessary ratio of oxygen to make it combustible. What does this mean? Propane is meant to follow a ratio of 4 parts of propane to 94 percent oxygen for it to be flammable and produce heat. 

Carbon Monoxide 

Carbon monoxide is poisonous but can be avoided when proper ventilation lets fresh oxygen in and out of the room for the propane heater. Consider it like a human. We need recycled fresh air, and so does your propane heater. 

Fire Safety 

Propane is combustible and flammable and can quickly catch onto things around it if proper safety is not prioritized. There are a few tips that are always recommended. 

  1. Keep a clear distance from combustible materials and chemicals such as paint thinners, gas, and cleaning supplies. 
  1. Ensure that it is placed on a safe concrete or non-flammable floor and that nothing is placed on top of it. 
  1. Opt for safety features like:
  • low oxygen sensor
  • high-temperature coated safety guard on the front
  • overheat protection with automatic tip-over shut-off.

This provides the best fire safety protection possible with the most precautions put in place. 

Proper Ventilation

For every 100,00 BTU/Hr heater output, you need ventilation and fresh air for every 3 square feet. Fresh air will come in and keep circulating to keep the heater from essentially sucking all the air in the room and producing carbon monoxide. This keeps the gas combustion properly controlled. 

To check the ventilation, you can look at the heater’s output or ask a technician for help if this is confusing. Taking this seriously is important because it is deadly if not adequately ventilated. An electrician can ensure the space is vented correctly for you. 

Can Propane Heaters Run in a Closed Garage? 

You shouldn’t run your propane heater in a closed garage without any fresh air coming in. This is especially true if you don’t have any windows. Enclosed spaces pose a threat to safety because of the carbon monoxide that gets produced by the heater. Nowadays, there are better options to consider that are more efficient and emit fewer toxins into the air. 

One of the options is a mounted propane heater where the propane tank actually sits outside. It’s built-in vented, which makes it much safer for indoor use. The second option is a portable propane heater. In this case, it is likely to have one of the safety features, such as a low-oxygen sensor. This helps prevent carbon monoxide build-up. This, paired with carbon monoxide detectors, helps prevent dangerous situations. 

To find a happy medium, you can always keep your garage half up and half down to let plenty of air in without all the heat escaping. Garages with windows are advantageous because you can place the heater near the window to push carbon monoxide outside faster. 

Indoor Propane Heater 

Indoor propane heaters were built with many safe-proof options that an outdoor propane heater doesn’t have. They are typically small portable heaters that can be moved around to different rooms as you need them. The low-oxygen sensor is one of the biggest components that it will have. 

There are a few different types of propane heaters for indoor use.

  • portable indoor propane heaters
  • wall-mounted propane indoor heaters
  • forced air propane indoor heaters
  • radiant indoor propane heaters.

Not every option listed above will be an excellent fit for every scenario. Different homes will have different needs, and a forced air propane indoor heater will make more sense than a radiant indoor propane heater. 

How Much Ventilation Does My Propane Heater Need? 

The ratio is 100,000 BTU/Hr heater output, you need ventilation and fresh air for every 3 square feet. Understanding the size of your garage and what type of propane heater you have will affect just how much fresh air you need, as mentioned above. 

Size of Your Garage 

The bigger the garage, the more ventilation you will need. 3 square feet per 100,000 BTU/Hr is quite a bit of fresh air. The problem with garages is they typically have one source where the fresh air can come from. If there are windows and the garage is not too big, it is easier to bring the fresh air in and get the carbon monoxide out. 

Luckily, the types of propane heaters today are a lot better in terms of efficiency than they used to be. Less carbon monoxide is emitted while the fuel burns. This poses less of a threat. But it depends on the type of propane heater you have. 

Type of Propane Heater 

There are four common indoor propane heaters that you can choose from. Each is designed for a specific situation. 

  1. Portable indoor propane heaters are used for temporary indoor use. They are usually small in size and great for power outages. 
  1. Wall-mounted propane indoor heaters don’t require electricity for heating and are highly recommended for all-around use. They have 99.9% efficiency and burn on liquid propane. 
  1. Forced air propane indoor heaters are great for heating up spaces quickly, especially when compared to a radiant heater. It can produce up to 125 BTU/Hr and has a heavy-duty fan to push the air out.  
  1. Radiant indoor propane heaters allow the heat to come out naturally, which is a little slower than some of the other models. It’s also meant for smaller spaces, around 450 square feet. 

So, no matter what we choose, how do we ensure it’s vented? 

Different types of propane heaters are vented in different ways. Here are three easy steps no matter what you have. 

How To Ventilate an Indoor Propane Heater

  1. Find the instruction manual. A mounted indoor propane heater will have a different vent duct than a ductless propane heater that can be set up in your fireplace. The manual will tell you the exact measurements that your hose will need to fit into the duct and airspace to ensure proper ventilation. 
  1. Next, you will want to ensure you have a source of fresh air when using. You should open the garage door or any windows to let in air. 
  1. Use carbon monoxide detectors on top of any sensors that come with the machine to monitor ventilation. 

A Great Option

Having a propane garage heater sounds scary, but it is a great option. Regardless of your type, it just takes some care and precaution to ensure it works in the right environment. It’s an affordable option to heat areas of a home, mainly a garage. Just be sure to consult an electrician on what works best for your home. 

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