Don’t Use Outdoor Gas Heaters Indoors

Just DON’T do it.

That is the simple message for people considering using an outdoor patio heater.

First, indoor gas heaters are extremely safe. They are designed to take in air and ventilation from within the room, which is significantly less than outdoors. Gas patio heaters are also very safe, but only when operated outside where they are designed to be used.

Using an outdoor gas patio heater indoors poses a ton of problems. Doing so is a bad idea that is dangerous to your property and potentially fatal to residents.

What is an Outdoor Heater?

The most common kind of outdoor heating appliance is patio heaters. These are typically either tall mushroom-style or shorter round-area heaters. Some are also designed for use in the garage or as industrial blow heaters.

Outdoor heaters like these are intended for large spaces with continuous gas supply and should never be used at home or in smaller enclosures.

Using gas cooking appliances as indoor heaters is also dangerous and could result in severe injuries or property damage.

Can You Use a Propane Heater Inside?

You can use a propane heater inside only if the propane heater is originally designed for indoor use. That includes a linear gas fireplace or wall-mounted propane gas heater.

This is because indoor propane heaters often have cleaner gas emissions and come with a ceiling/wall mounting bracket vented outside. Some indoor models are vent-free, but regardless, indoor heaters often have cleaner gas exhausts and comply with specific industry standards.

Propane gas heaters designed for an outdoor space can produce poisonous Carbon Monoxide – CO – as part of their combustion gases. If you use outdoor propane heaters indoors, their exhaust gases can get trapped inside your home, causing a potential CO poisoning hazard.

Different Gas Heater Specifications

Australia and New Zealand have some of the most stringent standards on gas appliance combustion emissions of any country in the world. As a result, our indoor gas heaters are very safe to use.

The gases of primary concern are CO (carbon monoxide) and NOX (nitric oxide and nitrogen dioxide), produced during incomplete combustion. To be certified in Australia and New Zealand, indoor gas heaters must meet or surpass these steep standards.

The same is not true for outdoor heaters. They are not required to meet the indoor heater emission standards because they are intended for outdoor use, with unrestricted ventilation.

Why Don’t They Build Them the Same?

Meeting indoor standards adds to the cost of designing and manufacturing indoor models. If you compare the prices of two types of heaters, you will see that indoor heaters cost more.

The manufacturers of outdoor heaters, trying to keep their units affordable, don’t design and build their heaters the same way.

Nothing is wrong with this practice as long as the consumer only uses the heater outdoors, as intended.

Radiant Outdoor Heaters

To be used safely, outdoor gas heaters need continuous ventilation as it’s impractical to heat the air with a convection heater. For this reason, most outdoor heaters are radiant heaters, which have a warming effect similar to basking under the sun.

Radiant heaters allow specific spaces within an area to be heated, primarily warming only the people and objects in front of the unit.

Amongst the advantages of radiant heaters is that they are generally a low-cost option and require no electrical connection, which would be problematic outdoors. These are great heaters as long as they remain outdoors.

Blower Heaters

Commercial blower heaters are typically used in warehouses, workshops, garages, factories, transport terminals, breeding sheds, and greenhouses. They are not suitable for domestic use, and when in use, ample fresh air ventilation must be provided.

It is also important that the minimum room volume requirements be observed as specified by the manufacturer.

Once again, these are excellent heaters as long as they are used according to the manufacturer’s instructions and safety advice.

Carbon Monoxide

Properly functioning gas appliances ensure complete combustion and are quite safe when used as intended.

As discussed, outdoor units may generate carbon monoxide, typically due to incomplete combustion, hence the need for better and unrestricted ventilation.

If you accidentally inhale a lot of carbon monoxide, you may feel persistent tiredness, shortness of breath, headaches, nausea, vomiting, and, in severe cases, loss of consciousness.

Suppose you experience any signs of carbon monoxide poisoning while operating any gas appliance. In that case, you should stop using it immediately, move to an area where you can breathe fresh air, and seek medical attention.

Combustion and Carbon Monoxide (CO)

All gas appliances, domestic and industrial, produce water vapour, Carbon Dioxide, heat, and usually very small amounts of Carbon Monoxide.

If installed and maintained correctly, a gas appliance provides quick and efficient heating, cooking, hot water, and more, and the products of combustion do not create hazardous situations.

If an appliance is not correctly installed and maintained or has been modified, the combustion products might change and become hazardous to the people around it.

Something as simple as a ventilation change (getting fresh air to the appliance to sustain complete combustion) may cause a gas appliance to malfunction and create a hazardous situation for the people around.

Sometimes, it is obvious when a gas appliance malfunctions, as it should produce sooty smoke, red or yellow flames, or poor performance are indicators, but sometimes you may not notice anything at all.

If Carbon Monoxide (CO) is produced and escapes the appliance into the surrounding air, it will not be obvious (no smell or taste) but very dangerous.

Gas appliances must be correctly installed and serviced every two years to maintain good combustion and safe, efficient operation.

Great Indoor Alternatives

There are lots of gas heaters that are designed and certified for safe indoor use.

Look for the certification label on the unit. Indoor gas heaters are broadly grouped as portable (vent-free) or flued heaters. These groups are sub-groups of radiant, convectors, radiant-convectors, power flued, flued radiant, and wall heaters. Virtually all are available in both LPG and Natural Gas model versions.

For gas heaters, gas input is expressed in MJ/hour, while heat output is measured in kW/hour. Generally speaking, greater gas input equals increased heat output, considering the relative energy efficiency ratings of the compared models.

Gas heaters in NZ are all tested and labelled for energy efficiency Star Ratings. To learn more, please see A Review of Your Indoor Gas Heater Choices

Keep Your Family Safe

So in summary:

• only use heaters designed for the indoors inside your home
• keep your outdoors heaters outside where they can be used safely
• always follow all the manufacturers’ instructions and safety advice