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Mini Split Room Sizing Guide

How to Properly Size Your Mini Split

By  |  Product Expert

If you're looking to upgrade your home's comfort, then getting the right-sized mini-split system is the most important step.

 

Mini Split with Inverter TechnologyMini splits are extremely efficient thanks to their inverter technology that enables your system to generate only the amount of heating or cooling needed to maintain the desired temperature. Even so, you'll want to ensure the system is properly sized for your home.

Although energy-efficient, if the system is too small, you'll find yourself wasting energy while your unit runs continuously, all the while failing to keep you comfortable in extreme conditions. This lack of performance will leave you on the hunt, yet again, for a better solution.

On the other hand, if the system is too large, you'll spend more on equipment and throw any energy savings out the window. Oversized equipment will also fail

prematurely due to short cycling (turning on and off frequently).


The bottom line is this: Improperly-sized equipment leads to decreased comfort, lower efficiency, increased service costs, and premature failure.

 

How to Size Your Mini-Split

Mini splits are sized in BTUs (British Thermal Units), which measures the amount of heat needed to raise the temperature of one pound of water by one degree Fahrenheit.

 
Our proprietary software will lead you through some brief, yet specific, questions about your space and provide the best sizing estimate you'll find from an online tool.
If you're looking to buy a multi-zone system, use the tool once per zone to get sizing estimates for each indoor unit (outdoor unit sizing for multi-zone systems may require additional calculations beyond the tool's capability).

 

Call us today and our experienced engineers are happy to provide a complete, professional sizing for your space at no cost to you. 

Step 1. Basic Info
Step 2. Room Info
Step 3. Construction
Step 4. Results
Total Load Calculations
Start Over
Cooling Load:
Heating Load:
Basic Room & Home Information
Room Size:
Zip Code:
Room Type:
Building Age:
Download As PDF
Print
* For more accurate load calculations, you can edit the detailed information below.
Skip To Results
Tell Us About Your Home
Fill out all of the fields provided to calculate your heating and cooling loads. We'll use that information to help you find the right mini split system for your home.
Select the approximate age range of your home. We will use this to make an estimate of the quality of insulation of your home.
Because different types of rooms are used differently, they have different heating and cooling needs.
Calculate Load Estimates
Temperature Information
High: 90°F | Low: 10°F
Outdoor Design Temp. determined by ZIP Code.
Next: To Wall Details
Wall Details
Select 'Yes' if this wall separates the space being conditioned from the outdoors or an unconditioned space like a garage. Otherwise, if this wall is adjacent to another conditioned space, select 'No'.
Enter the width of the wall. If only a portion of the wall is "Exposed", enter this width.
Select 'Yes' if this wall separates the space being conditioned from the outdoors or an unconditioned space like a garage. Otherwise, if this wall is adjacent to another conditioned space, select 'No'.
Enter the width of the wall. If only a portion of the wall is "Exposed", enter this width.
Select 'Yes' if this wall separates the space being conditioned from the outdoors or an unconditioned space like a garage. Otherwise, if this wall is adjacent to another conditioned space, select 'No'.
Enter the width of the wall. If only a portion of the wall is "Exposed", enter this width.
Select 'Yes' if this wall separates the space being conditioned from the outdoors or an unconditioned space like a garage. Otherwise, if this wall is adjacent to another conditioned space, select 'No'.
Enter the width of the wall. If only a portion of the wall is "Exposed", enter this width.
Next: To Window Details
Window Details
North
We assume Windows are 3'x4'. If your windows are larger or smaller, please adjust accordingly.
We assume French Doors are 3'x7'. Each half of a double door should be counted separately.
We assume Sliding Doors are 6'x7'. If your doors are larger or smaller, please adjust accordingly.
East
We assume Windows are 3'x4'. If your windows are larger or smaller, please adjust accordingly.
We assume French Doors are 3'x7'. Each half of a double door should be counted separately.
We assume Sliding Doors are 6'x7'. If your doors are larger or smaller, please adjust accordingly.
South
We assume Windows are 3'x4'. If your windows are larger or smaller, please adjust accordingly.
We assume French Doors are 3'x7'. Each half of a double door should be counted separately.
We assume Sliding Doors are 6'x7'. If your doors are larger or smaller, please adjust accordingly.
West
We assume Windows are 3'x4'. If your windows are larger or smaller, please adjust accordingly.
We assume French Doors are 3'x7'. Each half of a double door should be counted separately.
We assume Sliding Doors are 6'x7'. If your doors are larger or smaller, please adjust accordingly.
Next: To Ceiling Details
Garage Door Details
Each single garage door should be counted as 1 and each double garage door should be counted as 2.
Next: To Ceiling Details
Ceiling Details
Select 'Yes' if the ceiling separates your space from the outdoors, an attic, or any other unconditioned space. Otherwise, if there is another conditioned room above your space, select 'No'.
Enter the height of your ceiling. If you have a sloped, vaulted, or any other type of non-flat ceiling, enter the approximate average ceiling height.
Next: To Floor Details
Floor Details
Select 'Yes' if the floor separates your space from the outdoors, an unconditioned crawlspace or basment, or is a slab on grade. Otherwise, if your space is over a conditioned room, select 'No'.
Continue to Construction
Wall & Window Details
Garage Door Details
Ceiling Details
Floor Details
Previous
Submit & View Results
Basic Room & Home
Room Type
Room Size
ZIP Code
Building Age
Temperature
Edit
Avg. Outdoor Temp. High
°F
Avg. Outdoor Temp. Low
°F
Desired Indoor Cooling
°F
Desired Indoor Heating
°F
Walls
Edit
Wall Type
Wall Insulation Quality
North Wall Exposed Area
East Wall Exposed Area
South Wall Exposed Area
West Wall Exposed Area
Garage Door
Edit
# of Garage Doors
Garage Door Insulation Quality
Windows
Edit
Window Type
North Wall
East Wall
South Wall
West Wall
Ceiling
Edit
Ceiling Exposed
Ceiling Insulation Quality
Ceiling Type
Floor
Edit
Floor Exposed
Floor Insulation Quality
Floor Type
Load Results (BTU/hr)
Cooling load
Wall
Window
Ceiling
Floor
Bay
Infiltration
Internal
MRA ?
Moisture Removal Allowance: It is typical for roughly 30% of your air conditioner's capacity to be used to reduce the humidity in your home.
Total
Heating load
Wall
Window
Ceiling
Floor
Bay
Infiltration
Total
Print
Shop Mini Splits
Disclaimer: This sizing tool, although based on a version of the ACCA Manual J, is for informational use and is intended only as a guide to assist with finding the best product for your needs. Since the calculations are based on the information provided, Power Equipment Direct, Inc. assumes no responsibility for inaccuracies resulting from improperly sized equipment. For a complete, professional sizing estimate, please call us at
866-554-HEAT (4328).
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If you choose to start over, all of your entered information will be lost. Do you wish to continue?

Why Are Some Systems Measured in Tons?

Often times, you'll see central air systems measured in tonnage. While this term sounds like a measurement of weight, it has nothing to do with weight at all. Tonnage is a term used in the HVAC field that describes how much heat the system can remove from the indoor air in one hour.

Mini-splits aren't measured in tonnage because they are sized for smaller spaces. Instead, they are typically measured in BTUs (British Thermal Units). This is a much more universal system of measuring a condenser's ability to heat and cool an indoor area. You can convert tonnage to BTUs (1 Ton = 12,000 BTU) if you'd like to compare the two.

 

Get Sizing

Now that you know the basics of sizing, take the next step by using our free sizing calculator.

 

arrow Next: Mini Split System Builder

 



Mini Split Buyer's Guide Navigation

Home | Inverter Technology | Efficiency | Dehumidification | Heat Pumps vs A/C | Winterizing | Single-Zone vs Multi-Zone | How To Zone | Indoor Units | Accessories | Find an Installer | Mini Split Sizing Calculator | System Builder

 
 

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