how many rooms can a mini split ac cool

How many Rooms Can A Mini-Split AC Cool?

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A mini-split is pretty expensive and can cost you around $1,500 to $2,500 depending upon the size and features you are getting. A person paying for that much wants to know it will be worth it. If we look at the benefits of mini-split then we consider that it might be a better option than conventional air conditioners in situations where there is no ductwork. But you might be wondering if a single mini-split is going to fulfill the cooling requirements for your entire home? And how many rooms can I cover by a mini-split? In this article, every detail is given that you need to understand about the cooling of mini-split.

Before answering the question of the number of rooms a mini-split can cool, we need to understand that a mini-split has two parts: A condenser and an evaporating unit. The function of the evaporator is to pick the heat from indoor air and a condenser releases the heat to the outdoor air. So, an evaporator is required to cool the room. And a condenser in a mini-split can have more than one evaporator. In this way, a mini-split can cool a maximum of 4 rooms by adding extra evaporators to the condenser. The maximum number of evaporators that can be added to a condenser is four.

Following is the detail that you need to understand if you are planning to use a single mini-split air conditioner to cool multiple rooms.

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How does a mini-split AC cool multiple rooms?

Some of you might have heard a term before “Multi-zone ductless mini-split air conditioner”. Actually, it refers to the configuration of the mini-split where a single outdoor unit can be used with different indoor units or air handlers. In this configuration, each room having an indoor unit installed is considered as a zone and when more than 2 zones are connected, they form a cooling network.

What kind of system do I need to cool multiple rooms?

As it is explained how a single compressor is used with a number of indoor units. So, you need a mini-split with the required number of indoor air handlers and a single compressor to start using a multi-zone mini-split air conditioner system. You can add up to 9 indoor air handlers but for the best result, we will recommend you not to add more than 4 indoor units.

When to consider installing a multi-zone mini-split air conditioner?

You can use mini-split to cool multiple rooms anytime and it works just like a centralized cooling system. But are there any conditions or circumstances when mini-split will be better to cool multiple rooms? Surely there are few situations where the multi-zone configuration is great. Following are a few of those situations: 

  • When you are living in a home constructed many years ago. In such houses, it is not recommended to use centralized HVAC as ductwork can cause damage to the house. Or, in some homes ductwork is not feasible.
  • When you have to cover a large area, but your budget is not large enough. It can be a double story house, an office, or other building.
  • When you already have a centralized system but now you want to add some more areas and rooms where ductwork is not accessible.

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What is the working mechanism to cool multiple rooms?

Whether used for heating or cooling purposes, all mini-split air conditioners are comprised of outdoor and indoor apparatus. This indoor unit consists of three elements, including air-handlers, blowers, and the evaporator coil. Indoor air-handling units are placed strategically throughout a home, which allows for more efficient energy usage.

Air-handling units can be placed in several areas within the home, including both walls and ceilings. This can be beneficial for a number of situations, as necessary equipment can be placed in out of the way locations. Additionally, by placing the condensing unit outside, homeowners won’t be bothered by operation noise typically associated with air conditioners.

Split air conditioning systems are considered as more efficient and more reliable than conventional window ACs and others. This is due to their divided mechanism of working, as the name says, it’s split. Its work process is divided into outdoor and indoor (also known as air handlers) units which are connected by highly heat-insulated pipes.

The sleek and inconspicuous indoor units can be mounted on the wall or ceiling. You can regulate the temperature of each indoor unit with a remote control or a wall-mounted thermostat. Multiple indoor units can be connected to the same outdoor unit. Each indoor unit can then be programmed to maintain a different temperature, thus creating separate cooling zones. This differs from central systems where the thermostat setting determines the temperature in every room. So, I would be a lot helpful if someone is planning to install a mini-split air conditioning system. The performance of this system will be a lot efficient and cost-saving than the other systems because of its integration with separate indoor units (air handlers).

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How many BTUs do I need to cool multiple rooms?

Sizing of the split air conditioner is as important as taking the right number of calories in your diet. If it is not calculated properly, it will cause performance issues. BTU’s & tons are the two measuring units, used to estimate how much powerful is the AC. If someone is interested to install the mini-split unit for conditioning, he/she must calculate the size of the room and then as per calculations go for the AC size. The manufacturing makes different kinds of variants/models for different kinds of purposes and environments.

These protocols are not considered serious by most of the owners and eventually, they go for the inappropriate size of split AC. Then, two types of issues occur:

  • They install the small split AC unit as compared to the room area and AC could not cool the room due to its inappropriate size.
  • The other situation is vice versa. They chose the large split unit as compared to requirements that consume more power and ultimately increases the operational cost.

For your facilitation, we did some research and calculate the appropriate number of BTU’s required for different room sizes. Mini-split air conditioners cool a larger area at the same BTU level than do window air conditioners and portable air conditioners. Below is an approximate sizing guide:

  • 350 square feet = 9,000 BTU
  • 500 square feet = 12,000 BTU
  • 750 square feet = 18,000 BTU
  • 1000 square feet = 24,000 BTU
  • 1250 square feet = 30,000 BTU
  • 1500 square feet = 36,000 BTU

Often time, AC sizes are measured in tonnage. This unit seems like use for measuring weight but in actual it’s not. Tonnage is the unit which represents HVAC (heating, ventilation & air conditioning) system that how much heat system can remove from the inside air.

Generally, Tonnage (Ton) unit is used for bigger HVAC system like to operate in big rooms & halls etc.  While mini-splits AC’s are used for the smaller room sizes, so their size is measured in BTU’s. For the sake of simplicity, 1 Ton = 12,000 BTU’s.

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What if right size of split AC is not installed?

Proper mini-split conditioner sizing is very important for the efficient performance and level of the cooling capacity of the air conditioning system. If the installed system is too large or too small according to the room size, the air conditioning system will not work properly.

There could be other factors that can affect the performance of a split air conditioner like if the installation is not done properly or the indoor units are not mounted on the right location. Then the system will not be able to provide its maximum efficiency.

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