Finding out which size of AC unit is appropriate for your house may seem difficult but we are here to help. A unit that is too small will put a lot of unnecessary strain on the unit. It will also take much longer for the unit to bring your household down to the desired temperature. Many people may think bigger is better but that is not the case when it comes to AC units. An oversized unit will cool your home unevenly leading to hot and cold spots. In addition to the patchy cooling, it will cause a much higher energy bill. Finding the right sized unit is more than just knowing your square footage and picking out a brand. It is important to research thoroughly before choosing a product.
Where Should I Start?
There are a few questions you need to answer when deciding on an AC unit.
- What type of AC system do I want?
- What ratings do I want my system to have?
- Are there any other factors I want to consider?
What Type Of AC System Do I Want?
There are three main types of air conditioners that you can consider purchasing. These are Packaged AC, Ductless AC and Split-System AC systems. Each of these system types will work similarly while having slight differences in how they cool your household.
Packaged AC: This system consists of a single unit installed outside. All of the necessary parts such as the evaporator and condenser coils are found within this unit. Ductwork is used to transport the cool air from the outdoor unit into your home. Different kinds of packaged AC systems are used depending on what size the property is and how important energy efficiency is to you.
Ductless AC: This type of AC is installed in homes that do not have existing ductwork. It has one outdoor unit that connects to any number of indoor units. Indoor units are only able to cool one room, making it easy to have different temperature targets in each room. The indoor units are installed into the floor, wall or ceiling of the desired rooms.
Split System AC: This air conditioning type gets its name from having an indoor and outdoor unit that work together to keep your home cool. The Split System AC is the most popular system type in Hawaii. Many options are available when looking for a system of this type. Your Island Comfort HVAC technician can help you choose the right system for your desired size, price, efficiency, and noise level.
What Ratings Do I Want My System To Have?
After deciding on the appropriate system type for your home, it is important to look at ratings. AC units are rated for different levels of efficiency and cooling capacities. Energy efficiency and cooling capacities are rated with Seasonal Energy Efficiency Ratio (SEER) and British Thermal Units per Hour (BTUh), respectively.
SEER Rating: This rating system measures the average cooling season output divided by the total energy used of a specific unit. A higher SEER rating is correlated to a lower amount of energy used. This does not measure the average efficiency but the maximum efficiency. The most efficient units have a SEER rating of up to 22 but the average is 14 or 16.
BTUh Rating: BTUh measures how much energy was used to remove heat from your home in the span of one hour, measured in terms of tonnage. A BTUh of 12,000 is equal to the cooling capacity of one ton. Tonnage ratings for home air conditioners fall into half-ton increments, with a scale from 1.5-5 ton units. A 3 or 3.5 ton unit would likely be used for a 2,000 sq. foot home. This can vary depending on your area’s climate.
Are There Any Other Factors I Want To Consider?
After deciding on the unit type and rating specifications, you may still be unsure of which unit you need. Our technicians at Island Comfort can help you determine which size and style best suits your home based on certain factors. These factors will help narrow your search for the perfect AC system.
- Usage frequency of heat-generating appliances such as a gas stove
- Indoor temperature modifiers such as a fireplace
- Home construction materials like brick or wood
- Number and quality of exterior doors and windows
- Average temperature in your area
- Amount of direct sun exposure
- Quality of insulation and ductwork
- Number of residents
Manual J Calculation
All of these factors may cause you to feel overwhelmed. If you want further help, consider contacting your local HVAC dealer for an energy audit known as a Manual J Calculation. This calculation considers many factors including the ones above. They will recommend a correct AC size depending on these factors and some utility companies will even provide this service for free.
AC Unit Size Chart
If you are just looking around and aren’t ready for an energy audit, you can look over this size chart. This will give you a rough idea of what you should be looking for in an AC unit. This chart should not be used as the only form of research as many other factors need to be considered before purchasing an AC unit. It is very important to talk to a professional before you make your final decision.
Island Comfort AC Services
Island Comfort Air Conditioning is a family-owned and operated AC and heating company located on Oahu and Kauai. Our goal is to ensure your comfort comes first. We maintain, repair and replace your air conditioning in order to keep you cool no matter the climate. Contact us today to learn more about our services and how they can benefit you.