Avoiding Oversized & Undersized HVAC Systems with Load Calculations

Have you ever wondered why you must perform proper HVAC calculations before buying one for your house? In almost all systems, choosing the perfect size can notably impact both the longevity and performance of your machine.

Here, we will discuss some important things that will surely help in choosing the right size of the HVAC system.

Why Choose the Right-Sized HVAC System?

HVAC sizing or a heat load calculation includes a series of measurements of your residence. All these measurements will help professionals to select the right size unit for your HVAC system. This will keep your home comfortable all day long. There are some important reasons why professionals need to perform accurate heat load calculations. Some of those are:

• Improved Efficiency

If you choose an HVAC system that is too small compared to your requirement then it will become troublesome. The machine has to run continuously to reach the required temperature to cool down your home. 

In contrast, if you choose the right-sized HVAC system, it will use less amount of energy to run. Hence, it will effectively and efficiently cool or heat your house. When your system needs to run constantly it will waste lots of energy and eventually increase your utility bills.

• Improved Comfort

Have you ever entered your room on a hot summer day and felt that the inside is quite muggy? This usually happens if your HVAC system is not correctly sized. HVAC systems can cool down your home, along with pulling moisture from the air. So, if your machine is too large, it won’t run enough to pull that moisture. Hence, you will feel some amount of mugginess. 

Moreover, if your HVAC system is too big it will turn off and on quickly. This will result in poor airflow and circulation.

• System Durability

When you get an HVAC system, you must ensure that it will last for its expected lifespan. So, if you choose an oversized one, it will work hard by short cycling. Also, it will need lots of energy to start each time. In contrast, if you choose a too small one, it will get damaged very quickly due to overwork. So, only the right-sized one will work properly and last for several years with ease.

HVAC Load Calculation: Factors That May Affect It

• Internal Loads

The amount of heat that is generated by lighting, occupants, appliances, etc., inside your room may contribute to the overall heating and cooling load of your HVAV system. 

• Building Envelope

The characteristics of your building’s envelope can affect the overall heat load calculation of your HVAC system. Those characteristics include window types, insulation levels, construction materials, and more.

• Occupancy Patterns

When you can understand the occupancy schedule of your building and usage patterns, it can help you out with correct heat load calculation. This knowledge will help you to correctly determine internal heat losses and gains on a single day. 

• Climate Changes

Another vital factor that may affect HVAC load calculation is the climate. Thus, before buying your new HVAC system, you must know all about the climate surrounding your residence. 

• Role of Insulation

Another vital factor is the role of insulation. Only the correct amount of insulation can help by minimizing heat transfer. Thus, it can eventually reduce the load on your HVAC system. Insulation is generally installed in places like the roof, doors, windows and walls. Insulation ensures optimal performance of the HVAC system. 

Calculating HVAC Load: Step-by-step Guide

1. Bring Necessary Tools

Before starting the job, you need to arrange all the important tools that you must use. Also, you must bring items like wattmeters, blower doors, duct testers, etc.

2. Measure the Insulation Levels

Now, the first step is to correctly measure the total insulation level across the windows, walls, roofs, etc., of your building. 

3. Determine Window Spaces

In this step, you need to check out how much area your windows occupy. You must check the exact number in all your rooms. Also, you must take out any furniture that is blocking your window areas. This will allow you to determine the correct value.

4. Calculate the external and internal heat transfer rate

You can use a specific formula to calculate both the external and internal heat transfer rates. You can do this task just by checking your insulation measurements. 

5. Check Out Your Climate Conditions

You have to check out all those local climate conditions that could affect the overall energy efficiencies in your residence. Those may include options like humidity levels, temperatures, wind speeds, etc.

6. Input all values

Finally, just input all your calculations into a specialized tool or calculator. With this, you can determine the correct size of your HVAC system.

Common Mistakes That You Must Avoid

You must not forget to check the construction materials and insulation levels of your building. Insufficient insulation can lead to an incorrectly sized HVAC system. Thus, you may face comfort issues and energy inefficiency. Also, if you don’t check the properties of your building materials, you may perform incorrect load calculations. 
Hence, these are some vital things that you must check out before buying the right-sized HVAC system for your home. However, if you need an effective HVAC load calculation software, just rely on EDS.TECH.