What Size Mini Split Do You Need? BTU Sizing Chart

By | February 9, 2019

BTU Sizing Chart for Mini Split HVAC Units
Mini Split HVAC systems are great for heating and cooling and are very versatile able to be fitted into most any space.

Besides picking the right mini split manufacture how big a unit is needed also needs to be considered.

This is easy to do by calculating the square feet of the space to be maintained.

How to Get a Rooms Square Feet
To get the square feet of a room measure the length by the width and multiple the two together.
What Size Mini Split Do You Need
For example a room that is 20 feet long by 20 feet wide would be 20 X 20 = 400 Square Feet.

If there are more rooms such as closets simply do the same and add them to the total.

BTU Sizing Chart for Mini Split HVAC Units

Area Size Sq FtBTU's Needed
150 to 250 Sq Ft6,000 BTUs
250 to 300 Sq Ft7,000 BTUs
300 to 3508,000 BTUs
350 to 400 Sq Ft9,000 BTUs
400 to 450 Sq Ft10,000 BTUs
450 to 550 Sq Ft12,000 BTUs
550 to 700 Sq Ft14,000 BTUs
700 to 1,000 Sq Ft18,000 BTUs
1,000 to 1,200 Sq Ft21,000 BTUs
1,200 to 1,400 Sq Ft23,000 BTUs
1,500 Sq Ft24,000 BTUs

Take Into account Insulation and Climate
How well a home is insulated as well as the climate should also be considered.

For example a home poorly insulated will need a bigger unit than a home that is well insulated.

Climate should also be considered mainly in locations that extreme cold weather happens.

Most any mini split will have no problems cooling a space in air conditioner mode but may have problems heating in extremely cold climates.

Heat pump mini split units that both heat and cool reverse the air conditioning mode to heat during the winter.

This means they pull heat from the surrounding air which becomes more difficult as the temperature drops.

Most modern units will have no problems down to 10-20 degrees Fahrenheit but will start to struggle if the temperature gets much colder.

If the outside temperature becomes too cold the outside condensing coils will freeze up with ice.

When this happens a Heat Pump unit will go into what is called defrost mode.

Defrost mode is basically turning the air conditioning on to melt the ice off the outside coils.

Once the ice is melted off defrost mode will turn off and the unit will start heating again.

Often when it becomes very cold heat pumps will cycle between heating and cooling.

For example if you live in Alaska you will have no problems cooling in the summer, but the heating will stop once the temperature drops too much.

If you live in Nevada, Arizona, or Texas it will have no problems heating or cooling with heat pumps ideal for climates such as the American Southwest.


 




 

One thought on “What Size Mini Split Do You Need? BTU Sizing Chart

  1. Deeana

    Hi,
    I’m considering a Mrcool mini split for my double garage. I live in San Francisco East Bay Area and my garage faces South-West. It’s under 500sf with 8 ft ceiling. The sumner temp can reach up to 110 F and we have fair insulation in the garage. I’m wondering if a 12000btu unit will be effective enough for the space.

    Thanks.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.