The purpose of an HVAC system is to push out cool or heated air to make your interior temperatures comfortable compared to the outside air. This simple definition becomes more complicated when you start looking at air conditioning models since there are a couple of key different air control systems available. Each system has its own pros and cons that can help you determine what type of heating and cooling system would best work in your home or building.
Constant Volume Strategy
A constant volume or constant air volume system operates at a consistent rate of airflow but varies the temperature of that air to achieve a comfortable temperature inside your home. The system doesn't have a fan-only setting that can allow you to simply move existing air around your home. A constant volume system is either fully on or fully off.
The air conditioning unit for a constant volume system is fairly simple, low cost, and low maintenance. But the unit can also prove impractical for larger buildings or homes due to its constant functionality, which can drive up utility costs. Multi-zone constant volume units can work in mid-sized buildings but will involve higher costs to properly setup the system to disperse air throughout the building.
There are two main versions of the constant volume system: terminal reheat or mixed air. The terminal system ensures that your home reaches the maximum heating or minimum cooling temperature you indicated and then shuts the system off. The mixed air system runs both the hot air and cold air at the same time to mix and reach the optimal temperature before shutting off, which does a better job at achieving your desired temperature but doesn't do wonders for controlling humidity.
Variable Volume Strategy
Home central air conditioners are usually variable volume systems, which vary the rate of the airflow while the temperature of that air stays at a constant. The variable volume system has several advantages including more precision in temperature controls, the ability to run in fan-only mode, and energy savings associated with both of those qualities.
A constant volume system is better at controlling humidity and servicing various building sizes. The main disadvantages compared to a constant volume system are the higher initial price for the unit, the more complex parts and maintenance, and the fact that the system might be too expansive for smaller buildings with very simple heating and cooling needs. Contact a contractor, like HomeSmart From Xcel Energy, for more help.