Updated on Dec. 02, 2024
Looking for a simple, reliable, space-saving heat source? Consider a wall furnace. Get to know them and decide if one is right for your home.
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After Alice Parker received the first central air heating system patent in 1919, it didn’t take long for other home heating innovations to appear. Early central heating systems featured furnaces fired by coal, oil, gas and sometimes electricity, and while energy was relatively cheap in those days, installation wasn’t. A more economical option was to heat a house room-by-room and save on the installation costs, and that’s why wall heaters were invented.
The first coal-fired wall furnace, designed to minimize cost and necessary floor space, appeared around 1935. Recessed into the wall, the device used a fan to push warm air through through a register directly into the room in which it’s situated. Wall furnaces became popular in the 1950s because they provided a space-saving alternative to cast iron radiators, full-sized standard furnaces and electric baseboard heaters.
A wall furnace is still a viable home heating option, but is it a practical alternative to a furnace? Let’s find out.
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Also called a wall heater, a wall furnace is a self-contained, compact heating unit permanently mounted in or on the wall of a building and vented directly through the wall or roof.
Often producing warmth by burning fuel, but occasionally powered by electricity, a wall furnace circulates air inside a sealed internal chamber. The air is warmed by combustion of a fuel or by an electric heating element, and then a fan blows it out from the front of the heater and into the room.
Unlike a standard forced-air furnace, a modern wall furnace doesn’t require any ductwork to distribute warm air or vent combustion gases. Its small size and relatively simple installation make it ideal for heating small, open spaces.
Wall furnaces fall into three categories depending on how they generate heat:
“Generally,” says HVAC.com, “a wall heater will cost $450 to $550. If you choose to have it installed professionally, expect to pay an additional $150 to $200 in labor costs.” Besides costing much less than a furnace, which ranges from $1,500 to $8,000, installation costs are much lower because a wall unit doesn’t require ducts, and you simply vent it through the wall, which is simple to do.
But wall furnaces certainly aren’t for everyone. They average only half the heat output of central forced-air furnaces, depending on the size. And since they’re direct heaters — which means they rely on natural air movement in a building to heat the space — they become less effective the further away they are from an area that needs heat.
They work great for well-insulated small spaces with few walls, but they don’t perform as well in larger homes, especially under-insulated ones, during very cold winter months.
Modern, properly installed wall furnaces are remarkably safe. However, like all heat sources, they come with risks. Knowing these potential problems and how to deal with them will prepare you for the safest possible experience with a wall furnace.
“The Annual Fuel Utilization Efficiency ratio (AFUE) measures the standard energy efficiency of a wall-mounted heater,” says HVAC.com. “Wall-mounted heaters with AFUE ratings of 80-85% are mid-efficiency, while those with ratings above 90% are highly efficient.”
For the one room or mainly open concept space a wall furnace is designed to heat, even mid-range energy efficiency is quite good. Because wall furnaces blow warm air directly into the room instead of forcing it through a network of ducts, wall furnaces are more energy efficient than their central air counterparts. Keep in mind, however, that older units that work with a natural draft instead of a fan are often considerably less efficient.
Like all heating appliances, wall furnaces need routine maintenance.
Start by cleaning the outside of your furnace with a damp cloth, paying special attention to the vents, making sure they’re clear of dust and dirt. Next, shut off power to your furnace, then remove the outer cover to access the inside. Use a duster or a carefully handled vacuum cleaner with a soft brush attachment to remove dust and debris from the fan blades and motor.
If you have a gas-burning unit, you should clean your venting (the exhaust pipe that leads outside) once a year. Make sure to put on a dust mask and rubber gloves, then carefully open the vent pipe and remove any debris with a damp rag or vacuum cleaner.
Most modern wall furnaces include lots of specialized parts and computerized functions, timers and programs. That’s why if something goes wrong, you almost always need to call in a licensed specialist to fix it. Some common problems you might encounter are:
According to data from HVAC.com, a wall heater unit costs from $450 to $550, but a quick search online shows 2024 models costing as little as $200 and as much as $900. Installation is relatively simple, so the cost quoted by HVAC.com — $150 to $200 — is probably accurate, but since you have to vent it through the wall, the cost could be higher if you have brick or stone siding.
Generally, no. Hanging and venting the unit is simple enough, but most communities require licensed pros to hook up gas lines or wire new electric heaters.
