If you have a small stand-alone shop, or plan on building one, the consideration of heat is an important one. The bottom line is that there are many options and each situation is different.
By Ryan Shervill
This article set out to attain a definitive answer as to what is the best type of heating to use for a small home workshop. I came up with the following answer: It depends.
There are so many variables when it comes to small shop heating that it becomes impossible to recommend just one single form of heating. Shop size and ceiling height, local climate, amount of insulation, access to electricity, gas, or propane, budget, and of course, installation ability all come into play.
So rather than try and narrow it down to a single method, I’m going to take an overall look at the common types of heating available and look at their pros and cons. While this article won’t tell you what heater to buy, it will help serve as a starting point for your own research into what type of heater best suits your shop, your needs and your budget.
Let’s look at the most common types of heaters available to the home workshopper: Forced air gas/propane, radiant gas/ propane, electric radiant, electric forced air, portable electric element and convection. Although radiant in-floor heating is both effective and popular, it is virtually impossible to retrofit into an existing shop, so we won’t be covering it. However, if you are in the planning stages of a new shop, definitely take a look at in-floor systems.
Forced Air Gas/Propane
There are two main types of FA heaters found in workshops: wall-mounted heaters and overhead units. Plumbed to run on gas or propane, these units pull air into the unit and over a heat exchanger where it is warmed, and then returned to the shop. When looking at these units, it is imperative to find a direct-vent unit. What this means is that outside air is used for combustion and exhaust is vented outside. Not only does this make for more efficient heating, it is also safer as there is no flame open to the inside of the shop, which eliminates the risk of dust fires or explosions.
Pros: Fast, efficient heat. Low operating costs mean the heater can maintain a constant working temperature without breaking the bank. Rapid heating means the temperature can be lowered when you are not in the shop but will rapidly heat the space when it’s time to get to work.
Cons: One of the most expensive options to purchase and to install and you must have access to gas or propane. Installation costs vary but in addition to the price of the unit itself, you must also consider the cost for a gas fitter and pipe, as well as an electrician and any required electrical supplies such as wiring and a breaker. Also, this type of heater moves air, which can stir up latent dust that can lead to issues if you finish projects in your shop.
Gas radiant heating uses a similar setup to the FA above, but rather than warming and circulating the air, it converts the fuel to radiant heat. Radiant heat works very much like the sun in that it warms objects rather than the air. With a radiant tube setup, the heat is projected down into the shop and warms up your tools, your floor and you. The objects in the shop then release this heat into the air, making for a warm work environment. One of the best parts about radiant heat is that because it heats you directly, you can keep your shop at a lower temperature but still feel comfortable.
Pros: Very even, dry, comfortable heat. It is very quiet and because it doesn’t move, air dust is not a concern. High efficiency and low operating costs make it easier to maintain a constant temperature in the shop. The warming effects of radiant heat means that you can be working in a cold shop faster than if you had to wait for a forced air unit to bring up the temperature.
Cons: Like the FA units, these radiant heaters will generally require you to hire a pro for some aspects, as well as extra materials. Make sure when pricing units that you also take these extra costs into account.
Installed Electric Forced Air
(Photo by Dimplex North America)
These units also come in wall-mounted and overhead-mounted configurations. Acting very much like a home furnace, they draw air into the unit and pass it over an electric element to warm it, and then blow the warm air into the shop. Just like the radiant units, installation of these forced air heaters can vary from simple “plug and play” operation to a full-blown hardwired install.
Pros: These units tend to warm an area quickly and are generally available at a cost that is much lower than their gas counterparts. Very few moving parts mean maintenance is kept at a minimum and longevity tends to be very good.
Cons: Generally less efficient than gas heaters, they can cost more to operate. Heating elements should be kept clean for safety and efficiency.
Portable Electric Forced Air
(Photo by Dimplex North America)
These units range from small 250 watt electric micro heaters up to large 5000 watt construction heaters. Regardless of which model you look at, they all work pretty much the same way. A small fan draws air into the back of the unit and passes it over heating coils as it blows out the front. Power requirements vary depending on the model but most will plug into a standard 115 volt outlet with some larger models (such as the construction heaters) requiring 220V to operate. They can also be used as supplemental heating to keep temperatures above zero while the shop is not in use and a larger heating system is not active.
Pros: Inexpensive to purchase (less than $100), these heaters have thermostats built right into the unit and only require being plugged in to begin heating.
Maintenance is a simple matter of taking the heater outside and blowing it out with compressed air. If you are in a well insulated shop, these can be the least expensive heating method as any additional energy costs are offset by the low initial purchase price and lack of install charges.
Cons: Electricity costs can be high, and limited air volume means it can take a long time for these small heaters to bring up temperatures. Generally speaking, the thermostats tend not to be as accurate as a wall mounted stand alone, and they can be noisy to run.
(Photo by Lee Valley)
Like its gas-powered bigger brother above, an electric radiant uses infrared energy to heat the objects in a room rather than the room itself. Electric radiants come in a huge number of sizes, voltages, configurations and, of course, prices. At the smaller end of the scale are the inexpensive stand-alone units that simply plug into a 115V outlet. These small units are more suited to heating a specific area (such as a workbench) rather than the shop as a whole.
Some models contain a thermostat and many also incorporate a light for additional illumination over a work area. Larger units can heat an entire shop and do so with no air movement. These units can cost as much as a gas unit and will require wiring of electrical circuits and separate thermostats. They also have stringent clearance requirements.
Pros: Absolutely silent operation (all models), zero air disturbance (all models), can be installed where there is no access to gas or propane. Because the radiant heaters heat objects, you feel warmer than the surrounding air temperature, which means that thermostats can be kept lower while still maintaining a comfortable working environment
Cons: Smaller units only efficiently heat small areas and larger units can be quite expensive. When researching larger fixed units, ensure you factor in material and installation costs for hardwiring the units. Depending on where you live and your hydro rates, operation can be expensive compared to gas.
(Photo by Dimplex North America)
Convection heating draws air naturally over a heating element or plate and then releases it back into the room. The heating and cooling of the air creates a circular air current, eliminating the need for fans. Some examples of convection heaters are baseboards, oil-filled heaters and even radiators.
Pros: These heaters are readily available and tend to be inexpensive to purchase. They are absolutely silent to operate and because the air currents generated are so mild, there is no chance of the units stirring up dust.
Cons: While great for maintaining a constant temperature, these units are slow to heat a cold space and are best suited to well insulated shops that do not see a lot of in/out traffic. Fixed installations such as baseboards will require professional installation and operating costs can be quite high.
Some other alternatives, and why I don’t recommend them
While there is a financial and aesthetic appeal to a woodstove in a shop, there are a few reasons why I recommend avoiding them.
Floor space: Woodstoves take up a lot of shop space and space is always at a premium.
Safety: Some people claim that an open flame source can ignite fine airborne dust, and that may very well be true, but in my shop, the greater concern is flammable liquids and vapours. Being a multi-use shop, I spray flammable finishes and use/store all kinds of other flammables, so having an open flame 12″ above floor level isn’t comforting.
Heating: Woodstoves make fantastic heat but only when they’re lit. Maintaining temperatures 24/7 is near impossible and the resulting temperature swings can cause condensation and be hard on tools and supplies.
Insurance – Many insurance companies will not insure a woodshop heated by a woodstove. Make sure to check with your agent before installing a woodstove.
Non-vented (stand alone) fuel burning heaters
These heaters openly burn the fuel to create heat. Configurations range from catalytic type heaters to tubeshaped forced air construction heaters. Regardless, there are four things that all fuel burning heaters have in common: Lack of efficiency, carbon monoxide, fire danger and moisture.
Efficiency: Any fuel-burning appliance requires air to operate, which means that the air used by the heater will need to be replaced, and this air usually comes in the form of cold outside air being pulled into the shop.
CO: Every year hundreds of people die from CO poisoning and in many cases it was due to not following the number one safety rule when using these heaters: use in a well ventilated area.
Fire Danger: Similar to a woodstove, the open flame in these units poses a dust and vapour ignition danger. Also, some of these units can create sufficient heat to ignite flammable material, even when it is several feet away.
Moisture: Fuel burning appliances release water vapour as a byproduct of combustion, and too much water in a wood shop is a bad thing, especially when it comes to keeping wood stable and machines rust-free. For example, burning just one kg of propane releases 1.64 kgs of water vapour into the air … that’s a lot of moisture over a full heating season!
I’d like to give you one more point to consider though. In most cases, money spent on improving your shop’s insulation and sealing is a much better investment than even the most efficient heater. In my own shop I have my walls insulated to R22, my ceiling to R40, triple glazed windows and insulated doors. As a result, I heat my 26×34′, one-and- a-half storey shop full time with a simple $75 220V construction heater, and my heating costs are very low.