How Many Mini Splits Do I Need?
The ductless mini split is a wonder for providing cool comfort during the summers like those we experience in Boise, Idaho. They can turn a room. made virtually unusable due to the summer heat, into a cool oasis. All without installing expensive ductwork or utilizing unsightly window air conditioning units. The question is not so much when do I get one – but rather how many do I need?
When people think of mini splits, they typically think of an air handler mounted to a wall providing heat or cool air in a single room. And that is frequently how they are used. But that only scratches the surface of what a mini split is designed to do. The mini split has the capability of operating up to 8 zones, utilizing just one outdoor compressor.
So the question is this: ”How many mini splits do I need for my project? And what is the best way to configure my heating and cooling needs?
How Many Do I Need for My Project?
The first thing to do is to find out who the reputable HVAC contractors are in your area. In the Boise area Snowflake Air has been a trusted source for all things HVAC for years. Their team of expert technicians will listen to your needs and custom design a configuration that will bring reliable comfort to your home.
In order to provide the best information to give to your contractor, it is always a good idea to do your homework in advance to try to understand just what your requirements might be before your technician pays you a visit.
The most asked questions concern two things – cost and how many do I need?Here are just a few of the frequently asked questions:
- “How many rooms can a mini split cool?”
- “Do you need a mini split in every room?”
- “How many square feet does a mini split cool?”
- “How many BTU per square foot for a mini split?”
According to the Statista 2016 report, single-zone mini splits and multi-zone (2-zone, 3-zone, 4-zone, 5-zone, 6-zone, 7-zone, 8-zone) mini splits represent 77% share of all air conditioners worldwide. In short, a mini split is the most popular type of AC unit used today, so it’s no surprise that so many people are trying to figure out how many mini splits they need.
How Many BTUs Will I Need?
The number of BTUs that your system will consume is the determinant of how many mini splits you will need. It is that simple. But determining how many BTUs requires some simple math. Here is how it is calculated:
- Based on the size of your home, calculate the BTU requirements (primary factor). Usually, we use a 20 BTU per sq ft rule of thumb. Example: For a 1,500 sq ft home, you would need 1,500×20 = 30,000 BTU output. You can use one 30,000 BTU mini splits, two 15,000 BTU mini splits, or three 10,000 BTU mini splits.
- Be aware of the airflow and access to different rooms (secondary factor). Matching the cooling output (BTUs) is not enough. If you have a larger space, the airflow from a single 30,000 BTU mini split, for example, won’t be able to flow into all the rooms adequately. You will be left with hot pockets and uneven temperature dispersion. Having closed doors also prevents the cool air from coming into a closed room.
Based on these two factors, we can quite easily determine how many mini splits you need. We are going to show you how to calculate the BTUs, which mini split indoor handler sizes you can choose from, and how many mini splits you need for how many rooms.
- 1 outdoor unit. This is where the compressor and all the power come from.
- Several indoor units or air handlers. 1 outdoor unit can power 1, 2, 3, 4, 5, 6, 7, or even 8 indoor air handlers. We call this 1-zone, 2-zone, 3-zone, 4-zone, 5-zone, 6-zone, 7-zone, and 8-zone mini splits, respectively. Indoor air handlers can produce anywhere from 9,000 BTU to 3,6000 BTU (3-ton) cooling output.
Keeping it simple, a rule of thumb is that you need 20 BTUs for every square foot of living space assuming an 8ft ceiling.
This simply means that you need to multiply the square footage of the area of your home you want to cool by 20 BTU. It is important to note that to adequately cool or heat multiple rooms, doors need to be kept open to allow for the free movement of airflow.
Example 1: How many BTU do you need for a 1,000 sq ft house? How many mini splits for a 1,000 sq ft house?
BTU Requirement (1,000 Sq Ft) = 1,000 Sq Ft × 20 BTU = 20,000 BTU
In this example you can get the coverage that you need with the following two schematics:
- 1-zone mini split with 24,000 BTU air handler. This is a bit more than 20,000 BTU required but it’s better to have a bit more than a bit less.
- 2-zone mini split with 9,000 BTU and 12,000 BTU air handlers. The combined cooling output is 21,000 BTU; very close to the 20,000 BTU required.
How Many Rooms Can a Single Mini Split Cool or Heat?
As we mentioned before, a single mini split can heat or cool multiple rooms as long as there is sufficient airflow. A single air handler can adequately cool 2, 3, 4, or even 5 rooms. What you need to remember, however, is that all those rooms are considered an open space. That means no closed-off rooms or closed doors.
Using smaller units will enable multiple points of airflow. With multiple units cooling your house, it’s easier to get a more consistent temperature throughout the house. Using larger units – especially if the floor plan is not very open – might leave you with some hot pockets in rooms the farthest away from the air handler.
Leaving it to the Experts
If you are like me, I like to have my calculations double-checked by a reliable source who are experts in the business. But these few tips will give you some basic information to be able to ask questions and have a working knowledge of your requirements.
When in doubt, pick up the phone and contact your reliable Snowflake Air technician. Their team of experts will be able to answer your questions – and again if you’re like me double check your math!