Are Ductless Mini-Splits a Good Idea For Basements?

A finished basement requires heating and cooling, which means you need an appropriate HVAC system. Since basements aren’t always a part of ducted HVAC systems, you might have to get creative.

Mini splits are a popular choice for spaces without existing ductwork. All HVAC systems have pros and cons, depending on your home setup. It is important to research all options.

Let’s take a look at how well mini splits work in basements and if one might be right for you.

Are Ductless Mini-Splits Well-Suited For Basements?

Mini splits will heat and cool basement spaces as needed. A mini split system can certainly do the job, but whether it is the best choice for you depends on a variety of factors.

If you already have a central HVAC system with accessible ductwork, it may be better to simply add a few returns and supplies. However, that may not be possible if your furnace and AC are not sized for the increased square footage of the basement space.

If your basement is a large space, it is very likely that your furnace and AC will be too small for your home if you add to the ductwork. This means you will need to replace both systems with larger models. In that case, it is going to be cheaper to get a mini-split to heat and cool the basement.

In homes without ductwork, a mini split is really the only way to provide the space with both heating and cooling using a single system.

Other forms of heat (like electric baseboards) do not have the capability of cooling.

Reasons You Might Consider Ductless Mini-Splits For Your Basements

Easy Installation

Mini-splits have different designs, but the most common style has one or more indoor units that are mounted on a wall.

If you choose an exterior wall, this indoor unit requires only one 3″ (7.62 cm) hole for the refrigerant or coolant coil to connect to the outdoor condenser. This small hole will be sealed and hidden by the indoor unit itself.

Since these systems don’t use ductwork, there is greater flexibility with installation. The indoor units do take up some space on the wall, however. The photo below shows a typical indoor unit.

These units are very quiet when running (you probably won’t even be able to hear them!) but if wall space is a concern, that is something to keep in mind.

You can purchase recessed systems that don’t take up as much indoor space, but they are often costly and require more installation considerations.

They Offer Zoned Heating and Cooling

Mini-splits are a heat pump system, meaning they provide both heating and cooling. These units are ideal for temperature control in small spaces and individual rooms.

One or more indoor units can be connected to a single system. Each indoor unit has its own temperature control and, thus, is perfect for zoning.

If you have a large basement, you can adjust the indoor units to your desired temperatures, and you don’t need to waste energy heating and cooling spaces you aren’t using.

Consider the following scenarios:

• You may get a 0.75-ton (9,000 BTU) mini-split if your finished basement has only one small living area or room. 
• You can choose a 1.5-ton (18,000 BTU) system if the basement has more than one room, and each can have a separate evaporator unit or indoor head. 
• You can opt for a two-ton (24,000 BTU) unit if your basement has a living area, games room, gym, or home theater, with each zone having a separate indoor unit.

Each of the above setups requires only one exterior condenser outside your house. So, a basement can be fully covered with adequate heating and cooling.

Dehumidification Capabilities

Basements can suffer from high humidity and the problems associated with it.

Not all basements, of course. But if you have trouble with excess humidity, dampness, and stale odors in your basement, you should look into something that can regulate your humidity levels.

Mini-splits have a “dry mode” that lowers humidity levels. All air conditioners will naturally take some humidity out of your home when they cool the air, but a mini split on the “dry” setting will be a bit more effective.

Increased Energy Efficiency

Mini splits are integrated with their own smart technology to automatically adjust their operation for the greatest efficiency while maintaining their temperature settings. This is one of the main reasons for their efficiency.

The other big reason is heat transfer. The mini split doesn’t have to create heat like a furnace; it simply transfers it from one area to another using refrigerant.

So, despite being a fully electric system, mini splits have a low cost of operation.

If the unit was sized correctly, it should be cheaper to run than traditional HVAC equipment.

Final Thoughts

Ductless mini-splits are an excellent choice for heating and cooling a basement space in most situations. They are easy to install and highly efficient.

However, the initial installation can be costly. If you’re on a tight budget and your central HVAC system can handle the addition of your basement, you might choose to go that route. 

With most HVAC decisions, it would be best to talk with an HVAC professional to get their opinion on your home set up.

All homes are just a little different. Most companies offer free estimates and will be happy to answer any questions you may have.