What Size AC Unit Do I Need?

On those hot, sticky, summer days, it’s wonderful to have your own home air conditioner, ready to burst into action and cool down the house. But, in order to get the best results, you need to choose the right type and size of AC system. If you pick one that’s too small, it’ll fail to properly cool the home. Choose one that’s too big, and you’ll spend more than you really need to.

What size AC unit do I need?” is one of the most asked questions by people before buying their new system, and it can be a tricky one to answer. There are multiple factors to take into account, like the actual AC unit size, the square footage of your home, and other metrics. In this AC unit size guide, we’ll show you exactly how to pick the right size unit.

Why Does AC Size Matter?

So, why do you even need to use an AC unit size calculator or consider window AC unit sizes in the first place? Well, the size of the air conditioner you install will have a massive influence over how effective and useful it actually turns out to be. You can’t simply pick any AC unit and expect it to cool down your entire home with ease. 

There are lots of sizes and types, each with its own capacities and performance levels. Logically, you might therefore decide to pick a super-powered, high-end AC unit that has the highest performance ratings, but that’s not a wise move either, as an oversized AC unit can cost you a fortune in bills and will simply be too much for certain homes.

At the same time, if you select a unit that is way too small and lacking in power to suit your home or space, you’ll find that it won’t make much difference to the general temperature. Not only that, but it might break down, as it’ll be working extra hard to try to cool down the space and could easily fall into disrepair, requiring lots of AC maintenance and costly upkeep.

So, when it comes to “What size AC unit do I need?” you have to find the right balance. You can’t pick one that’s too big, nor should you install one that is too small. You need to find an AC installation that’s just right for your home, providing the optimal level of cooling and energy efficiency.

How to Size Your Air Conditioner

The first step in answering “What size AC unit do I need?” is to work out the square footage of your home or the room you want to cool down. But that’s not all, you’ll also need to understand key terms on the AC unit size chart, like BTUs and SEER ratings. This can all sound pretty complicated at first, but it’s relatively easy, once you break it all down.

What Are BTUs?

If you look at an AC unit size calculator or check the product specifications of popular AC units for sale, you may see the term “BTU” mentioned a lot. BTU stands for British Thermal Unit, and it’s a unit of measurement that basically tells you how well the AC unit can cool down a space. Units with more BTUs are generally more effective at cooling bigger spaces rapidly.

What Is a SEER Rating?

As well as figuring out BTUs to square feet and AC unit size charts, you’ll also notice that many air conditioners have a SEER rating on the box. SEER stands for Seasonal Energy Efficiency Ratio, and it tells us how much cooling an AC unit can provide per season, divided by the amount of energy used. In other words, it shows how efficient the unit is.

A higher rating means that the unit is more efficient and will use less energy to cool the home, meaning lower bills for you. The best models also come with Energy Star Certification, meaning that they use even less energy than the others. So, as well as considering the size of the air conditioner, you should also pay attention to its SEER score.

What Size Air Condition Do I Need?

When choosing an air conditioner for your home, you must consider a few factors.

  • The first one is your location and the climate where you live.
  • The second factor is the size of your home and how many rooms it has. The larger your house is, the more AC units will be needed to cool down every room.
  • You should also consider the number of people living in each room.
  • Also, determine how many windows there are and doors leading outside. Determine where sunlight enters during hot summer days and when temperatures fall below freezing point during winter months.
  • Another important factor is to decide what size and number of the room(s) or area(s) you’re trying to cool down. You might think all you need to do is look at your square footage and order the same size unit as your house. However, that’s not always the case!
  • Number of people and pets living there
  • Insulation in your home
  • How much Energy Efficiency Matters to you
  • How much noise will bother you
  • Where your home is located (North vs. South)
  • The design of your home. For example, high ceilings.
  • Your desired temperature range (hotter in summer or cooler in winter)

So, now that we know the basics of window AC unit sizes and specifications, it’s much easier to answer “What size AC unit do I need?” However, you’ll still need to take a few more factors into account to pick the perfect model, starting with your home or room size:

Air Conditioner Sizing by Home Size

The first thing you’ll want to do is measure the square footage of your home. Air conditioners are rated by their BTUs or British thermal units. BTU measures how much heat they can remove from a space. BTUs are measured per hour: the higher the number of BTUs per hour, the more powerful they are, and the faster they cool down a room. Finally, air conditioners are measured in tons: one ton equals 12,000 BTUs per hour. For example, if your home is 1,500 square feet and has two bedrooms, one bathroom, and a dining room/kitchen combination, you would need a unit with at least 12,000 BTUs of cooling power. On the other hand, if yours is just one bedroom and one bathroom, then 8,000 BTUs should be enough for your needs.

The list below shows the most appropriate number of BTUs for varying sizes of rooms and homes:

  • 100 to 150 sq ft – 5,000 BTUs 
  • 150 to 250 sq ft – 6,000 BTUs 
  • 250 to 300 sq ft – 7,000 BTUs 
  • 300 to 350 sq ft – 8,000 BTUs 
  • 350 to 400 sq ft – 9,000 BTUs 
  • 400 to 450 sq ft – 10,000 BTUs 
  • 450 to 550 sq ft – 12,000 BTUs 
  • 550 to 700 sq ft – 14,000 BTUs 
  • 700 to 1,000 sq ft – 18,000 BTUs 
  • 1,000 to 1,200 sq ft – 21,000 BTUs 
  • 1,200 to 1,400 sq ft – 23,000 BTUs

Window AC Sizing by Room Type

Room type can also have an impact, especially when installing a window unit.  Typically, larger and wider rooms that are used more often, like bedrooms and living rooms, will need bigger and more powerful units. Meanwhile, small spaces that are used more infrequently, like guest rooms, dining rooms, and home offices, can have smaller units.

Other Factors That Affect Air Conditioner Size Requirements

A range of other factors may impact which model you should buy, including: 

  • Climate: Areas that have lots of sun and warmth for large parts of the year will need more powerful units that can run longer, like an 8kw air conditioner or 5kw air conditioner, rather than a weaker 2kw air conditioner.
  • Shade and Sun: If your home gets lots of shade, it’ll cool down more easily on its own, so you won’t need such a big air conditioning system. If it’s in the sun a lot, you’ll need a bigger and better unit.
  • Insulation: Well-insulated homes do a good job of maintaining a consistent internal temperature, warmer in winter and cooler in summer. If your home has poor insulation, you’ll need a bigger AC.

How Do I Calculate What Size Air Conditioner I Need?

The easiest way to calculate which size AC unit you need is to work out the square footage of the home and then multiply that figure by 25. That’ll tell you roughly how many BTUs you need. For example, for a 300-square-foot space, we multiply 300 x 25 to get 7,500, so you should buy a 7,500 BTU unit.

Is It Better to Oversize or Undersize AC?

Oversizing an air conditioner might sound like a good idea, but it isn’t always recommended. An oversized unit will be priced more than some homeowners want to spend on their monthly utility bills. However, “undersized” AC units could lead to problems such as inadequate cooling levels during summertime which could cause mold growth inside walls.

The first thing you should think about when buying an AC for your luxury home is how many square feet of space it will cool.

Choosing the right size air conditioner for your luxury home can be difficult. You don’t want to oversize or undersize your AC. However, you must also ensure it has the best features for your home.

In the world of air conditioning, it’s a question that comes up all the time: Is it better to oversize or undersize AC?

This is a tricky question. While we can’t answer it definitively, we can give you tips on deciding which is right for your home.

First, let’s look at what “oversizing” means. An AC that is too large for your home will run less efficiently than one that’s properly sized for the space. This means it will use more energy and cost more money to operate than a smaller AC would.

On the other hand, the unit may struggle to keep up with cooling demand in warmer months if you have an undersized AC. That can lead to high energy bills and even damage to your unit.

Oversizing or undersizing an AC depends on several factors:

  • size of your home
  • how many people live there
  • what kind of climate zone you live in
  • how often you use your air conditioner during the summer months
  • the number of rooms

So, what’s the best size AC for your luxury home?

The answer depends on:

  • how much space you have in each room of your home
  • how many rooms are connected together
  • how much heat they generate on their own

Choose the Best AC Installation Company

If you want to get the best possible unit and the optimum installation for your home, you’ll need to work with the best. Choose a trusted and leading HVAC contractor in Las Vegas or your local area to get a quick, flawless installation and instant cooling throughout your home. This will minimize the risk of any problems or inefficiencies with the system.

As we can see, picking the right AC size isn’t always easy, but once you know the size of your home and understand the basics of BTUs, it becomes a lot simpler. If you have any doubts or queries, make sure to contact HVAC professionals near you for advice and recommendations.