How Big An Area Can A Ductless AC Cool?

Often referred to as ductless air conditioners, mini-splits are a quick and efficient way to cool your home. The choice to install a mini-split will normally depend on a number of criteria for each homeowner. A few important elements to consider include the size of your home, the number and size of the rooms you wish to cool, and the setup of your current HVAC system. However, how much space can a single ductless air conditioner cool?

Smaller units typically start at around 9,000 BTUs and can cool about 350 square feet of space, while larger ductless systems with a BTU of 36,000 can efficiently cool a room of up to 1,500 total square feet (the size of approximately 2-3 bedrooms).

Similar to other types of AC units, ductless air conditioner systems are available in a range of capacities and can be set up for various home or office HVAC configurations. Before investing in a mini-split system, it’s critical to understand the ductless unit’s capacity for your house.

Cooling Power

The size of a ductless air conditioner system’s heating/cooling pump, from which its output of heating and cooling capability is measured in BTUs, determines the majority of the unit’s cooling capacity. The amount of heat required to increase the temperature of a pound of water by one degree Fahrenheit is referred to as the BTU of an air conditioner (or heating system).

What Size Of Ductless AC Do You Require?

Knowing the entire square footage of each room you want to cool can help you calculate the capacity your mini-split system needs to successfully cool your house. A ductless air conditioning system’s capacity is expressed in BTUs. Because mini-split air conditioning systems are so effective at distributing air throughout a house, you may have noticed that their BTU rating is often lower than that of window air conditioners.

The formulas for calculating BTU capacity based on the square footage of a room are listed below:

350 to 500 square feet produce 9,000 to 12,000 BTUs, 750 to 1,000 square feet produce 18,000 to 24,000 BTUs, and 1,250 to 1500 square feet provide 30,000 to 3600 BTUs.

After discussing how to size a ductless system for room sizes, we’ll examine several additional space-related variables that may affect your ductless system’s capability.

Insulating Capacities

In most cases, when performing a walk-through for mini-split insulation, HVAC specialists will quickly assess the current insulation in your home. There is a significant probability that the insulation between the walls in your house is adequate if it is relatively new or has just undergone renovations. The effectiveness of a mini-split unit in each room can be increased by adding fresh insulation to the walls, but older homes are normally advised against this.

In addition to giving you the best temperature control possible and reducing the size of the pump required for your ductless system, good insulation ensures that cold air cannot escape through the walls of your home.

Interior Sunlight

A room with skylights or a lot of sunlight can easily boost cooling costs, and you’ll probably need a bigger pump in that space. Depending on the time of day they arrive, most HVAC technicians will assess the light levels in the space during a walkthrough.

More sunlight will make a room demand more energy to cool, so you might want to think about alternate cooling options like blackout curtains or other covers.

The Number Of Doors And Windows

A room’s windows and doors frequently result in some inefficiency when it comes to heating and cooling. The reason is that they have cracks and crevices that allow air to escape from the room. Temperatures will be maintained more effectively in a room with excellent insulation and just one window than in one with inadequate insulation and three or more windows.

For instance, because they are typically larger spaces with numerous windows and lots of open space, basements are normally easier to cool and require less energy. Your ductless cooling system might need more air handlers and a bigger pump if your house is full of big rooms with lots of windows inside. Additionally, the capacity needs for your ductless air conditioning system may increase if your doors and windows are extremely old or poorly insulated.

Do All Rooms Need A Ductless AC Unit?

Since the outside condenser unit can be connected to several units within the house, there is no need to install a ductless unit in every room of your house. This entails placing the indoor units in the primary living spaces of the majority of modern and historic residences. You can also have an additional outdoor condenser unit (for a total of 2) to help efficiently cool the home if it is a larger home, in which case more inside units would be required.

Many homeowners divide their homes into heating and cooling “zones” by using mini-split systems. A single-zone ductless system uses one indoor unit and one outside condensing unit to cool the interior of your home.

Homeowners who have rooms without the necessary ductwork for central air conditioning sometimes use this type of system. The ductless system’s ability to cover the entire room’s square footage should be the primary concern when using single-zone air conditioners.

The operation of a multi-zone ductless system is identical to that of a single zone system, but it can cool down additional rooms in your house. A refrigeration line connects each zone (or indoor unit) to the outdoor condensing unit. Most homes adopting this configuration will have no more than four indoor zones.

A multi-zone system might be an excellent choice to cool the various rooms of your house if it lacks central air conditioning, especially if it has numerous storeys. Multi-zone variants are therefore perfect for basements, apartment complexes, and small commercial spaces. All of the interior units can be handled by a single outdoor unit, with the only exception being that they shouldn’t all be running at full capacity simultaneously to avoid overloading the outdoor unit.

What Happens If The AC Is Too Big?

The performance of a system depends on a ductless pump that is the right size. The least amount of energy is required to properly and efficiently chill your home with a mini-split system that is the right size. However, an excessive pump can lead to mechanical problems with your appliance and ultimately cost you money in repair and replacement.

Homeowners frequently believe that purchasing a larger ductless pump than they actually want will meet their heating and cooling requirements better. That is not the situation. The biggest problem with an excessive pump is “short cycling,” which happens when the device repeatedly goes off and on within random, brief intervals of time. This problem has the potential to cause the AC unit to degrade prematurely. When this happens, the ductless system will experience problems and eventually stop working.

Humidity is another problem. Dehumidifiers can also be used in ductless systems. However, if the AC unit short-cycles frequently, it will be less effective at removing humidity. As a result, your home’s humidity levels may rise above average.

It’s also vital to keep in mind that bigger pumps cost more because the price of a pump is directly correlated with its size and capacity. Additionally, since the larger pump will need more electricity to match its capacity, you run the danger of paying a higher energy bill.

What Takes Place If the Unit Is Undersized?

A ductless system that is too small will not only be ineffective but also insufficient. Your living rooms may not be at the proper temperature if your ductless pump is too tiny. Even while the system may be functioning well, you’ll soon realize that your home is not being sufficiently warmed or cooled.

While failing to meet your expectations for comfort or temperature, the mini-split system will continue to use energy. Additionally, because the unit isn’t large enough to effectively deliver cold air to various regions of your home, you can see warm spots there. The pump will strain to compensate for its inability to adequately chill your home, which causes the unit to deteriorate more quickly than it would have otherwise.

What Sets Ductless Air Conditioners Apart From Mini-Split Systems?

The terms “mini-split” and “ductless air conditioner” are actually used to refer to the same kind of AC system. Mini-splits are the name given to ductless air conditioning systems since they are simply scaled-down versions of conventional central air conditioning systems, which are also known as “split systems” and share the same indoor air handler and outdoor condensing unit.

In Conclusion

If you take the time to speak with a qualified HVAC specialist, you can be sure that your ductless mini-split system is sized correctly for your house and the regions you want to cool. We hope that this tutorial has given you a better understanding of the ductless system sizing process and its significance.