Some common HVAC terms, definitions and in-depth explanations:
A new unit also gives you a new product warranty. Replacing the indoor unit at the same time as the outdoor unit gives you added peace of mind, knowing the new warranty covers the entire system.
At first, replacing only an air conditioner or heat pump outdoor unit may appear to be a bargain. That is, until you consider the lower efficiency, decreased reliability and high cost of ownership associated with single-unit replacement. It may cost more to replace an entire system, but this gives you more efficiency, reliability and comfort.
Furnace technology has advanced significantly in recent years. Modern furnaces are designed to provide more even and efficient heating than past furnaces, which can impact both how your system operates and what you notice about your system.
To better regulate temperatures and airflow, modern furnaces move more air over the heat exchanger than older furnaces. The air that comes out of your furnace registers may not seem as warm as the air from your old furnace, but overall airflow is improved. Better airflow means higher comfort.
Two-stage heating means the furnace has two levels of heat output: high for cold winter days and low for milder days. Since the low setting is adequate to meet household-cooling demands 80% of the time, a two-stage unit runs for longer periods and provides more even heat distribution.
Longer, low-capacity operation has many advantages:
Two-stage heating eliminates the temperature swings associated with standard furnaces, regulating temperature to within as little as one degree of the thermostat setting.
Two-stage furnaces start in the first stage, when the amount of heat required is lower, instead of reaching full capacity all at once. That means there's no sudden "kick" or blast of air.
Low-speed operation allows your filters to capture more contaminants (because air is constantly passing through them), so you can breathe easier.
Because the furnace operates mostly in its lower-capacity first stage, it burns less fuel than a standard furnace that always runs at full capacity and shuts off when the heating demand has been met.
Variable speed motors can actually save you money on your energy bills, as they consume less electricity than standard motors.
Variable speed technology also means you will gain heating efficiency or AFUE.
Variable speed motors are excellent for zoning, which allows you to customize your comfort in different areas of your home and control your energy bills.
A variable speed motor can also help clean the air in your home. When the fan is in constant operation (indicated by the "Fan" setting on your thermostat), the motor will continue to slowly circulate air, allowing filters to capture more contaminants.
A variable speed motor allows you to control the amount of humidity in your home for improved indoor air quality and comfort.