If you already have a ventless heater in your garage, then you probably know the answer. But if you are just thinking about purchasing one, you will want to know if it can create moisture before you buy. So here are some facts that you can consider before making your final decision.
Why use a ventless garage heater?
The great thing about ventless heaters is that they are easy to use and offer efficient heating for confined spaces. Their efficiency can reach up to 99% while keeping the price relatively low. The compact design of these heaters makes them perfect for garages, where they can be placed in any corner and produce heat within minutes. The installation cost of such a device is limited to the device itself and the gas line attached to it. A portable model will not even require fixing on a wall.
What is the price you pay for these advantages?
As is with everything in life, downsides come along with them. The air intake necessary for gas burning and the exhaust of its products will be confined within your garage. That is the main cause of the impressive efficiency level and installation ease. There is no pipe connecting the heater with a space outside of your garage, like with direct vent heaters, so all the produced heat stays inside. But so do all the products of natural gas or propane combustion.
Producers of high-quality ventless heaters declare that 99,9% of those products are carbon dioxide and water vapor. Some byproducts that might be present are nitrogen oxides, carbon monoxide, and soot. Although they are only 0,1%, they can cause health problems when accumulated in a small space, and that is why people prefer not to install ventless heaters in their bedrooms.
Moisture creation issue
Even if you leave aside the small quantities of those dangerous substances, water vapor is still one of the main burning products. Every pound of natural gas combusted produces 2.25 lb. of water vapor, about 12% of the total exhaust by weight. This moisture will accumulate in your garage and will inevitably increase humidity. And as you can imagine, after some point, it will not stay in the air and will create condensate on surfaces that will be colder than the other. Mold or rust will start to appear, and you will have to pay a hefty sum of money to reverse the effects.
But using a ventless heater is not necessarily wrong. For example, if your garage is equipped with some kind of ventilation and there is enough airflow, you can ignore all of these facts and enjoy the benefits coming along with owning one of these heaters. But it would be best to understand that you will lose some heat along with the airflow, so you can’t count to get the efficiency declared for closed spaces.
If you do not have ventilation in your garage, you should probably look for a different heating solution.