How Big Of An Ac Unit Do I Need

Share This Post

Want To Learn More About Cooling Your Room

How To Clean Your Air Conditioner Condenser

Here are other useful tools related to this calculator:

efficiently use energyrecommended air conditioner size

What Size Of Window Ac Do I Need

Window ACs are typically not designed for huge spaces and will only cool one room or area. The size of the AC you need is measured in BTUs, reflecting how much power it has. The more BTUs a window AC has, the larger the area it can cool.

Its important that you get the most appropriate AC for your space. Well explain how to accurately measure your room in a second, but heres a rough breakdown of the size of AC youll need based on the area it will be operating in. Remember, you will need to consider the other factors we discussed above because this could dramatically change the window AC size you need.

Room Area To Be Cooled Window AC Size

Therefore, the room is 120 square feet.

Triangular Rooms

Triangular rooms are slightly more complicated, and the equation is slightly different. First, youll need to measure one side of your room, and then from the center of that side all the way to the far wall. This will give you the base length and the height length. You then need to do ½ x base x height to work out the area. Heres an example:

One wall is 12 feet long and the distance from the middle of this wall to the other wall is 20 feet. 0.5 x 12 x 30 = 180 Therefore, the room is 180 square feet.

Importance Of A Proper Size Air Conditioner

Installing the correct size air conditioning unit for your home makes a significant impact on your comfort and energy bills. You might think that bigger is always better, but that is not the case. If you purchase an air conditioner that is too large, it will cool your space too rapidly. This will cause it to continuously shut off and turn back on, which leads to lower efficiency and higher costs and sometimes more broken air conditioner repairs.

On the other hand, if you choose a unit that is too small for your home, it will run constantly to cool the space, and in some cases may never achieve the desired temperature. This increases your costs and may leave you too warm in the summer.

Installing an air conditioning unit in your home is a big undertaking and choosing the wrong size unit can greatly impact your energy costs. Thats why we recommend leaving the process to the professionals in the HVAC industry.

Don’t Miss: Water Heater Gas Control Valve

Choosing An Air Conditioner

When buying an air conditioner, you should select one that either provides or comes close providing the amount of BTUs you home requires. All conditioners are labeled with the amount of BTUs they provide.

Keep in mind, though, that the chart above tells you how many BTUs you will require under ideal conditions. There are a number of variables that can alter this calculation.

Why Is Mini Split Sizing So Important

How Large of a Portable Air Conditioning Unit Do I Need?

A properly-sized mini split system can save energy and keep you comfortable for years. Thats why so many people are asking how big of a mini split do I need? Before we get into the details on how to make sure your system is sized correctly, lets take a closer look at some potential issues associated with improper sizing:

To avoid these issues and enjoy efficient, reliable comfort, find a Carrier expert to determine what size system you need. If you want to get an idea of what size system youll need before your local professional arrives, try using our mini split sizing calculator for a close approximation.

Recommended Reading: Comfort Zone Heater Not Working

Tips On How To Save On Ac Energy Costs

Modern air conditioners are quite efficient and work well. Many brands and models will last you several years, with central systems and mini-split ACs averaging 20+ years of reliable service.

There are, though, other things you can do to ensure the AC works at its most efficient levels and saves you money on your home energy bills.

Wall Mounted Air Conditioning Units

There are two types of wall mounted air conditioning units central and split systems. Wall mounted units are perfect for medium to large rooms in your home.

Central air conditioning involves one indoor heat exchanger which distributes cool or warm air throughout the whole house. Its a large unit so its best if youve got space to install this in a loft or basement. The outdoor component connects to the heat exchanger and pushes refrigerant around the system you can find out more about how air conditioning works in our blog post.

Split systems consist of 1 external and between 1 and 5 internal units. When theres more than 1 internal unit, theyre called multi-split systems. The parts work in much the same way, but each internal unit is smaller because its not designed to service the whole house. Split systems are ideal if you dont have room for a large unit in your loft or basement.

You May Like: Why Is My Home Ac Not Blowing Cold Air

What Size Hvac System Should You Get

So what size HVAC unit should you get for your home size? For a single what size HVAC unit, what matters the most is what area of your home to run it in and what temperature range you desire throughout.

For average sized homes between 1,500 to 3,000 square feet, what size HVAC system you should purchase is what’s called a three-ton unit. Depending on what your desired temperature range is will depend what size what size HVAC system you decide to get.

For every degree above or below what the desired temperature is set at will require what size HVAC system you should purchase to be an additional 500 BTUs.

For example, if your desired temperature is set at 71 degrees and what size what size HVAC unit you should get for your home size is a three-ton air conditioning or heating capacity system, then this what size what size HVAC unit should get what size HVAC system your home requires for that temperature range is 6,000 BTUs.

Call 1-800-277-9400 today to make an appointment with an HVAC pro! We can recommend and install a right-sized system for your home.


What Type Of Air Conditioner Is Best For An 1800 Sq Ft Space

air conditioner tonnage calculation : how to find air conditioner size

The best air conditioner for an 1800 square foot space is a window unit. Installing a window AC unit is quick and easy, and it does not take up much space.

The AC unit can also be run continuously when its hot outside because the windows are open. The following are some of the best air conditioners for 1800 square feet.

Recommended Reading: Power Vent Water Heater 50 Gallon

The Importance Of Choosing The Correct Air Conditioner Size

Choosing the right air conditioner for a given room size is essential if you want to minimize your electricity bill. A small air conditioner will have a hard time cooling a large room, or it might not be able to cool it at all. On the other hand, choosing a huge air conditioner could cool the room very fast but won’t dehumidify the room at all. This particular instance leaves the room cold and, at the same time, clammy, which is not comfortable at all. Therefore, it is crucial to decide what size of air conditioner you need before buying one.

This air conditioner room size calculator will help determine the recommended output power your air conditioning unit needs to function perfectly. Of course, this depends on the room’s area, the average number of people regularly in the room, and its exposure to the sun.

If you do not know your room’s covered area yet, you can find it by using any measuring tools you have lying around and measuring your room’s length and width. Input these values in our air conditioner room size calculator to instantly get your room’s area. If you have an irregularly shaped room, you can use our square footage calculator and choose the multiple rooms option to help you determine the area of your room.

Once you know the area of your room, check the chart below for its corresponding recommended base air conditioner capacity:

Room Area
2,000-2,500 34,000

How Do I Know What Size Central Air Conditioner Do I Need

So how do you determine what size of an air conditioner you need for your home? You have probably seen air conditioners with BTU measurements or sizes on them but without a clear understanding of what BTU really mean, it can be hard to figure out which unit is the right sizing of air conditioners for your home.

Don’t Miss: Ac Won’t Stop Running

How Do I Calculate What Size Air Conditioner I Need

To determine the air conditioner size needed to cool a space, measure its square footage first.

Next, determine how many BTUs are required to provide cooling for each square foot of the room based on this information. The final step is to choose a unit that provides at least this amount of cooling per watt.

Here is the formula you can use. BTU= .

In the case of an 1800-square-foot room, the calculation would be as follows.

=36000 BTU

In addition to converting BTU to Tons, you can also convert BTU to Kilograms. To do this, you only have to divide the number of BTU by 12000. It is possible to use the formula as follows to calculate this value. Ton= BTU/12000.

In the case of your room, for example, you will need a cooling system with 36000 BTUs. Here is the calculation that needs to be done.

= BTU/12000


=3 tons

Additionally, an AC unit with a higher SEER rating will be more efficient and therefore use fewer BTUs to provide the same level of cooling.

Despite this, higher SEER ratings also cost more, so consult an HVAC technician to make sure the AC unit you choose meets your needs.

The Problem With Undersized Ac Units

How Large Of An Air Conditioner Do I Need / What Size Air Conditioner ...

AC units that are too small for your home, on the other hand, present several issues as well.

Your home is never cool enough It can try as hard as it can, but an undersized AC unit is always at a disadvantage when it comes to cooling an area that is too big for it. The best it can probably do is cool a certain area of the house, but leave other parts warm.

It will run continuously and lead to higher energy bills Did you buy a small air conditioner because you think it will use less energy? While an ACs capacity typically matches its energy usage, an undersized air conditioner will use more power simply because it is likely to run continuously, barely stopping for breath. A small AC will try its best to cool a given area, and if the areas too big, it will just keep on running until it does that job, which it never really does.

The units lifespan gets shorter If oversized units suffer wear and tear because of frequent short-cycling, undersized units suffer the same wear and tear, but for the opposite reason: failure to go through healthy on and off cycles. The stress of the practically non-stop operation of your undersized AC unit leads to more frequent and costly repairs and lessens its overall lifespan.

You May Like: Why Ac Not Blowing Cold Air

Cooling Loads Vs Cooling Capacity

When talking with your HVAC expert you may hear some different terms like load and capacity that could confuse you. Were here to help you cut through the jargon so you can communicate with your HVAC technician.

A load is how much cooling a home needs, while the capacity is how much cooling the air conditioning system can supply.

A load is influenced by the house, its orientation to the sun, how many occupants it has, and how many heat-generating appliances are in the home. A cooling load is calculated through a Manual J calculation to make sure that the proper air conditioning system is installed with the right cooling capacity to remove heat from your home.

How To Size A Window Air Conditioner

Its important to understand the key factors which will influence how big an AC youll need. Theres a lot to consider, but heres a list of the main things to look out for:

Room Size

The size of your room impacts the amount of cooling youll need. A large room will need more BTUs, and a smaller room wont need as many. A more powerful AC will cost more, and it can be tempting to go with a cheaper option, but dont. The window AC you go for should be influenced first and foremost by the size of the room its operating in.

Number & Size of Windows

For a window AC, you will need at least one window, but its worth considering the shape and size. You can get modern window ACs that will fit in a range of shapes, but youll need to measure it carefully before buying one.

If you have a room with several windows, it might also mean that the room is poorly insulated with a lot of heat transfer. Youll potentially need a more powerful AC to compensate.

Related Article Can I Still Use a Windows AC If There is No Windows Available?


Many people think insulation is just to keep the heat in, but its actually used to stop heat transfer. This means it can keep a room cool or hot depending on what the conditions are. If you have insulation, it should make it easier to maintain a consistent temperature, and your window AC doesnt need to be as powerful.

Depending on the quality of your insulation, you may be able to get a window AC with 10-15% fewer BTUs.

Shade or Sun

Don’t Miss: Best Recliner With Heat And Massage

Factors That Impact How Big Of An Ac Unit You Need

As you may have already guessed there are a number of important variables that will effect the size of the central air system your house requires.

Total number of square feet is just one of these factors.

In fact, you can have homes that are identical in size, but still call for completely different size units.

Here are the additional factors that need to be taken into consideration:

  • Number of people living in the house:
  • Number, age and orientation of windows and how well they are insulated
  • Amount of sunshine your home gets: you may have very bright, hot rooms that get a lot of sun, as well as darker, naturally coolers rooms where the sun does not come in a lot.
  • Insulation: how much of it and what type. For example, its very important to have proper roof and attic insulation, as that is where a lot of the air escapes.
  • Number of skylights

Where Does The Air Come From

WHAT AIR CONDITIONER SIZE DO I NEED? How To Size Air Conditioner For Your House

But theres another catch: If the portable air conditioner only has a vent hose, and no air intake hose, the air blowing out the window is the air youve just cooled. Worse, this air will be replaced with hot outdoor air coming in through doors, windows and cracks. When outdoor temperatures are above 85°F, a portable air conditioner cant absorb enough heat to offset the extra load, so the room temperature will start to rise.

Dual-hose air conditioners like the Whynter ARC-12 and Whynter ARC-14 use a dedicated air intake hose, so the air being cooled stays in your room. But even after solving that problem theres a limit to how effective a portable air conditioner can be: The department of energy down-rates the big ARC-14, which is technically capable of capturing 14,000 BTUs, to an effective performance of only 9,000 BTUs in average conditions.

This chart shows our tests of 12,000 BTU single-hose and dual-hose air conditioners against an 8,000 BTU window unit in 97°F heat. Its no contest. All the inefficiencies add up to make portable air conditioners a bad solution for anything more than moderate 85°F heat. A bigger portable like the Whynter ARC-14 has a bigger fan and can circulate the air in a bigger room, but of course its also louder.

Recommended Reading: Precision Air Heating And Cooling

How Many Tons Of Ac Do I Need Per Square Foot

Las Vegas is known for its heat, so you might think youre erring on the side of caution if you buy an oversized air conditioner. Unfortunately, this can cause far more problems than it solves. And it leaves people asking questions like, how to know my ac size or what size unit do I need? If youre only replacing a broken system, you can simply confirm the model numbers to make sure you get the right size.

HVAC units are designed to run uninterrupted for long periods, during which time they can remove excess humidity while cooling your building. If the HVAC unit is too large, it will constantly stop and start, leading to a decreased lifespan for your HVAC unit along with humidity problems inside your building.

In order to determine the right amount of AC for your building, a contractor will do a Manual J calculation. This takes into account factors that can affect a buildings ability to retain heat and how much air is needed to cool an area. These can include a buildings square footage, its exposure to sunlight, the state of its insulation, and more.

Other factors that can greatly affect the results of a Manual J calculation include the buildings year of construction, its climate zone, and whether or not it is a residential or commercial property.

If you are thinking about replacing your HVAC unit, you can conduct your own estimate to get an idea about your cooling needs. For example, each ton of air conditioning can remove 12,000 BTUs from a building in an hour.

Related Posts