RV Furnace Filter Location: What You Need To Know

RV owners love fresh air and the great outdoors! But what about when inside your RV? Is your HVAC system giving that air quality you deserve? When running your RV furnace, are you getting those airborne particles, dirt, and contaminants out of the air?

Many of us know that filters are great for improving our indoor quality. And that regular filter maintenance of an RV furnace and air conditioner will keep dust particles down. So, where is your RV furnace filter location? The short answer is that you don’t have one! It’s true; many RVs on the road today do not have an RV furnace filter.

That was the bad news. The good news is that you can easily add an air filter if you would like; however, there are some safety concerns to know about first. Your RV furnace and return cold air are set up so you can easily add a filter to improve indoor air quality. This post will review how to install an RV furnace filter, including:

  • The reason why manufacturers don’t have an RV furnace filter
  • Best place to locate your RV furnace filter
  • How to install the filter
  • Replacement and maintenance of filter

Whether you have a camper, travel trailer, or fifth wheel, this post will help you understand the furnace filter location.

Table of Contents

RV Furnace and Air Conditioner

Let’s first understand the “why” there is no RV furnace filter. Your RV air conditioner has an AC filter that can easily be replaced, so why not the RV furnace? The answer to that question is two-fold.

First, your RV air conditioner typically runs more continuously and is more sensitive to dust, and the second reason is that the furnace could pose more of a safety concern if there is a blockage and not the proper air flow.

Using this knowledge, manufacturers have determined that the minimum need for a filter and the requirements to replace it often outweigh the need to install it in their RVs. It is recommended not to modify the furnace operation but rather to install a separate air purifier to improve indoor air quality.

However, if you are up to the task and want to install an RV furnace filter, keep reading.


Your RV furnace produces heat. Hopefully, there’s no surprise there. It uses propane (as the fuel source) and DC power from your battery for the blower motor (this is so your furnace can run without electricity). For that heat to be safe, the air constantly moves through the return air, through the blower motor, and out of your ducts. This is sometimes called a forced air furnace, similar to a house furnace.

All goes well when air flowing. However, if there is a restriction in air movement, the heat can build up in the furnace and cause a safety issue. So, if a furnace air filter is installed, it is important to check the filter material periodically to ensure it is not clogged and has good air flow.

Location of RV Furnace Filter

The best place for the RV filter location is at the cold air return. This is also called the blower compartment because this is where the air returns to the blower and redistributes the hot air through the ducts.

This cold air is usually a 1-foot by 2-foot open grille, usually located in the center of the RV. A common spot is just under the refrigerator or the RV stove.

To gain access to this blower compartment, remove the screws holding this grille. Once removed, you should have an open space and access to the furnace.

Installation of Furnace Air Filter

To install an air filter, measure the opening. Usually, the grille size works as it is slightly larger than the opening (which is what you want). Then, go to a home center or hardware store to see the closest size available filter. Again, there is no standard RV furnace filter size to ask about, so you will need to see what is available at the closest dimension of your opening. If you can’t find the exact size, look for a little bigger filter. You may need to cut the filter material later to have it fit.

Install filter at blower compartment.

The next step is to place the furnace filter into the blower compartment. The air filter will be loose as nothing prevents it from pushing in. In this step, you can install 1×1 wood strips on each side of the interior compartment to hold the filter in place. Or, you can use the screws from the grille to hold the filter in place. Check that your grille screws are long enough and go through the blower compartment wood. If so, you can use those screws to hold the filter in place. You may have to grab the filter material in place while you screw in. Otherwise, it will just push back into the compartment.

Maintenance of Furnace Filter

Now that you have installed a furnace air filter, the key is maintaining constant maintenance and replacing a dirty filter. As we reviewed above, a clogged air filter can restrict flow and be a potential hazard to your RV.

Especially with the filter close to the floor, pet dander, and debris will quickly get collected into the filter and get clogged.

I suggest you check your filter every month during the heating season. To replace, unscrew the grill cover, remove the old filter, and replace it with a new filter. Doing this regularly will give you better indoor air quality as those air particles are caught in the furnace filter.

Final Thoughts

While it’s true that most RVs do not come equipped with a furnace filter, the silver lining is that you have the option to add one to enhance your air quality. However, knowing the safety concerns associated with restricted airflow and heat buildup in the furnace is crucial. Manufacturers have made the calculated decision not to include a filter due to these safety factors and recommend using separate air purifiers instead. If you decide to install a filter, careful measurement and placement in the cold air return are essential, followed by regular maintenance to prevent clogging and ensure a safer, cleaner indoor environment during your travels.