How to select a contractor and purchase a new HVAC system

What is an Applied Product and Why are HVAC Systems Considered an Applied Product?

I’ve heard HVAC systems are an “applied product.” What does that mean and why should I care? Read this article to learn why HVAC systems are different from most consumer products and why who you buy from makes a bigger difference than what dealer you buy your care from.

Many consumers are not familiar with the concept of an applied product. That’s because most products they are responsible for purchasing are not applied products. Applied products are not usable until they are installed into an environment and because the installation and the environment are partly responsible for their use and performance the effectiveness of the product will vary greatly.

Examples of non-applied products are virtually endless. Some examples of larger, more complex mechanical products that are non-applied products are cars, lawn mowers, even computers. When you buy these products, you may choose how you use them, but they can be bought as complete systems where nothing else is required in order to use them.

Examples of applied products include many products that go into construction. Toilets, water heaters, even flooring, siding, doors, etc. The way the product is applied during the design phase and how it’s actually installed will contribute significantly to how they look and perform. 

When you are replacing your HVAC system, the reason why choosing a good partner/contractor is so important is that a good contractor will help advise you how to get the best value and performance from your investment and then install it in the best way to maximize it’s performance and longevity.

Poorly Applied Product Example

Let’s use an extreme example to illustrate what would happen if a perfectly good product is applied incorrectly. Let’s pretend that a house is one-story, 1200 square feet. The previous system that was installed at the house was a 4 ton gas furnace and A/C package unit. The homeowner was very frustrated that their system never ran reliably, their house was always to humid, and it ultimately failed after 8 years. Of course the homeowner naturally blames the system for being poor quality and they are happy to get this junk out of their house in favor of a new manufacturer. They go out and look for replacement bids. Once they get something new installed everything will be fine, right? Wrong. Unless the new contractor addresses some underlying problems, the new system will operate and last about the same as the previous system. So what are the problems?

System Oversized — It’s highly likely based on the information above the system is oversized and short-cycling (not running long enough). This means it has too much capacity for the home it’s installed in. A system should be sized appropriately for the application. Even at 400 sq ft per ton, the system is oversized. If the homeowner is complaining of high humidity, that is also a sign the system is short-cycling. Short-cycling will not only make the home less comfortable, it also shortens the life of the equipment with excessive stop/starts. 

Restricted Air Flow – If the home was designed for a smaller system and the ductwork installed is undersized, the HVAC system will be plagued by problems associated with restricted airflow until it finally dies. These include poor efficiency, freezing coils, and ultimately failure of components. This problem can even be made worse by bad technicians. It’s relatively easy to diagnose a poor airflow problem as a low refrigerant issue. Adding refrigerant will only put additional stress on the unit until it fails.

The Correct Replacement Approach

When the homeowner gets a new system it’s important that the contractor runs a manual load calculation to determine the proper size of the new unit and then evaluate the existing duct capacity to determine if it is optimal or requires modification. Once the correct decisions are made and the new unit is carefully installed the homeowner should expect lower energy bills, more reliable operation, and a more comfortable home. Having the right product, correctly applied makes all the difference!