If you've been looking for a new air conditioner and have decided to go with a packaged terminal air conditioner for your hotel, hospital, senior residential facility, or office building, choosing the right size of the unit is a very important decision that should consider several factors. What are these? Keep reading to learn more.

Before we dive further, let’s discuss why choosing the right size of your next commercial grade PTAC unit is so important in the first place.

A packaged terminal air conditioner, often abbreviated as PTAC, is a heating & cooling self-contained unit that was mainly developed to cut costs and increase energy efficiency in commercial places. These units have standardized dimensions such as 42x16 inches, 36x15 inches, and 40x15 inches but come in 4 different cooling capacities ranging from 7,000 BTUs to 24,000 BTUs. BTUs basically indicate how powerful a unit is in terms of energy the compressor system takes to remove heat from the air. The indicator describes the amount of energy that can be produced per hour. For instance, a 5,000 BTUs PTAC unit can produce up to 5,000 BTUs of energy per hour. Now let's consider two possible scenarios:

1) Your PTAC Unit Is Too Small For Your Room

A unit with low BTU capacity would fail to provide adequate cooling for your room and would run almost continuously, striving to get the room to your desired temperature. A unit running for long hours will also significantly increase your electricity bills.

2) Your PTAC Unit Is Too Large For Your Room

A high BTU capacity unit would instantly cool your room, but because of that, your unit would be forced to cycle on and off too frequently. This will not only shorten the unit’s lifespan but also lead to energy wastage. You are very likely to have a damp room and mold issues if the PTAC BTU level is higher than what your space needs.

Now that we know choosing the right size of your PTAC unit can save you a lot of headaches, the next question is how to choose the right size of PTAC for your building/space. Here is a comprehensive guide to help you decide that.

Guide To PTAC Sizing:

Generally speaking, PTAC units are available in (but not limited to) four size classes and can be used for the following room sizes:

BTUs Room Size
7,000 BTU 200-300 sq ft
9,000 BTU 300-400 sq ft
12,000 BTU 400-550 sq ft
15,000 BTU 500-675 sq ft

However, room size is just one of the many factors that you should be considering before buying a PTAC unit. Other factors such as ceiling height, number of people who share the room, insulation, and outside weather, especially the amount of sunlight the room receives might change the number of BTUs required for a certain room. Therefore, the BTU guidelines are not hard and fast but will give you a decent estimate of the requirements.

You can also check the following suggestions by our HVAC experts to make a better decision:

  • For a heavily shaded room, reduce BTU capacity by 10 percent.
  • For a very sunny room, increase BTU capacity by 10 percent.
  • More than two people sharing the space? Add 600 BTUs for each additional person.
  • Choosing a PTAC unit for a kitchen? Consider increasing BTU capacity by 4,000 BTUs.
  • Is room at upper-story? Increase BTU capacity by 10 percent.

Still Not Sure About The Size You Need?

If finding the right size for your PTAC unit seems a little too hard, feel free to call one of our HVAC experts at (877) 776-8228, to make sizing your PTAC unit easier. Our experts will help you determine the BTUs required for your room after analyzing all the factors and make the right decision.

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