Common Myths About HVAC Balancing Valves

A cooling or heating water system is said to be “in balance” when the flow rates specified for the system and the actual flow rates within the system as it runs match.  Automatic or manual balancing valves are a way to manage flow rates and keep the pressure and flow of water consistent throughout the entire system – ensuring a consistent temperature in the building and keeping energy costs at a minimum.

There are a number of commonly held misperceptions about HVAC balancing valves and how to outfit a water system with them.

Myth #1: Automatic balancing valves are more expensive than manual.
Because manual balancing valves require the entire system to be configured manually (in multiple terminals) by a professional, many argue that the installation costs are too high to justify the lower cost of the parts.  The system may need to be entirely re-adjusted if maintenance that disturbs the flow is required.  While automatic balancing valves cost more, they balance the system automatically and don’t require as much time or labor to install or maintain – meaning lower operating costs.

Myth #2: Control valves are self-balancing, just like automatic balancing valves.
Control valves open and close in response to changes in pressure relative to a “set point” – i.e. if the water pressure changes, they can open or close automatically to keep the system at optimal functioning.  However, these valves are not designed to automatically balance the system the way balancing valves do.  A two-way control valve can only balance a system if the unites of the terminal are set for the maximum load and if the system has a stable control loop – and even then, this won’t work outside of a certain thermostat temperature range.  Control valves could balance the system, but only if all those variables are met.

Myth #3: Failing to replace your air conditioner filter will overwork your system and damage the coils.
While replacing your air filter in accordance with the manufacturer’s specifications helps keep the system running optimally, a slightly clogged filter (read: a system with slightly restricted air flow) will not cause the system to burn more gas.  If anything, it will cause a gas furnace to set itself to a slower mode and burn less gas.  An air conditioning system only requires enough air flow to prevent the coil and coil hook-up kits from freezing over.

For more information on balancing valve and coil options, visit Flo-Pac online.