The last thing anyone needs is to face a Los Angeles summer with an air conditioning system that’s prone to failure. One of the main reasons why an air conditioner may fail is that it is incorrectly sized. If an HVAC system is not sized to fit your home, it will be also be less effective and inefficient, leading to higher energy bills. It’s important to get your HVAC system professionally sized to ensure that it meets your needs. There are online tools available to help you size your HVAC system, but they don’t take into account many other key factors that affect their performance and efficiency. In this article, we will take a closer at how to size an HVAC system correctly.

A Brief HVAC Sizing Primer

The first thing that you need to know about sizing an HVAC system is that there is no one size fits all equation to follow. Many people believe that they can match an HVAC system to their home, based only on the square footage of their home. It is true that the square footage is an important factor, but there are other important factors to consider. You will encounter problems if you use a standard formula or online tool without taking these other factors into consideration. Another common approach that people take is to simply purchase the largest HVAC system that they can afford. But this doesn’t work, installing a unit that is too large will cool the space down too quickly and waste a great deal of energy. Larger systems also cost more to install, and it’s harder to maintain comfortable indoor temperatures. If the HVAC system is too small, it will struggle to treat the air; the equipment will be overworked and frequent failures will follow.

5 Key HVAC Sizing Variables Explained

When you hire a local HVAC specialist to size an HVAC system for your home, there are five key variables that they will investigate. A complex load calculation will be carried out, and then they can advise you on your HVAC system options. This process typically takes less than an hour, but it could take longer in a larger home or a home that has a complex layout. Let’s take a look at these HVAC sizing variables in more detail.

  1. The Age of Your Home

Many older homes or offices do not have modern ventilation or ductwork systems. As such, they cannot meet the needs of a modern HVAC system, but in some cases, a retrofit may be possible. A good ventilation system is vital if you want to get the best efficiency out of your HVAC system. Another key issue is the electrical system condition; it must be up to code to handle the needs of your new heating and cooling equipment.

  1. The Number and Conditions of Windows

The location and number of windows in your home is a major contributing factor in home heating and cooling. If you have windows that receive plenty of sunshine throughout the day, then you will have more heat in your home. Any cooling system has to work hard to maintain a comfortable indoor temperature in LA, and natural heat can be a real problem. The window type is also important; a single pane window is less efficient than a double or triple paned alternative. Any window treatments that you have are also important because the shade can lower the thermal impact of sunlight.

  1. Weatherstripping

Air leaks reduce the efficiency of your HVAC system, and they need to be located and fixed. When treated air escapes, the money spent to treat it is wasted, and the HVAC equipment has to work harder to compensate. Every weatherstripping surface around doors and windows needs to be sealed to maximize efficiency.

  1. Your Home Placement

The placement of your home is important. It will be easier to keep your home cooler in summer if you get a lot of natural shade. Even a difference of 90º will have a dramatic effect on the size of the HVAC system that you need and its efficiency. Careful landscaping with shady trees in key areas can boost your HVAC efficiency by up to 20%.

  1. Insulation Levels

Every home has an R-value, this is a measurement of the insulation levels, and it has a huge impact on home heating and cooling. The R-value must be included in any comprehensive load calculation if you want to find the ideal HVAC system size for your home. Insulation is vital to achieve and maintain a comfortable indoor temperature. If you need extra insulation, this can be added later when your ductwork is installed.

The Problems Caused by Incorrectly Sized HVAC Systems

If the HVAC system is too small, it will run constantly as it attempts to treat the air in your home. Some systems may operate in shorter bursts, and they attempt to treat the air and then shut down due to overworking. Homeowners may notice moisture accumulating in their homes because the HVAC system cannot maintain the temperature. Over time this could lead to mold growth and an associated reduction in the indoor air quality (IAQ).

If the HVAC system is too large, it will work better in some regards, but there are still problems. When the system is too large, it will get the room to the desired temperature too quickly, and the system will not run for long enough to remove dehumidify the air. Again, this introduces more moisture and the associated damp and mold growth issues. Larger HVAC systems consume more energy, and this leads to higher energy bills.

Hiring an HVAC Specialist to Size your System

As you can see, there are many more variables to consider than just the square footage of your home. A professional HVAC specialist will use the Manual J method to make the most accurate load calculation. They have the skills, knowledge, experience, and specialist tools to help you choose the right HVAC system to suit your needs. This will ensure that you get the best performance and energy efficiency to keep your home comfortable without breaking the bank.