High Volume Low Speed (HVLS) fans are a type of monster ceiling fan that is used in commercial and industrial buildings. Just like a ceiling fan at home, they save money by stopping temperature stratification during the heating season. They also make folks feel cooler in hot weather.
What are they?
HVLS fans are ceiling fans that are big and run at slow speeds. Typically, they cut a 24-foot diameter circle with their blades. Their size reminds me of helicopter blades. The speed of rotation is slower than your average fan to keep the power use low. A lot of engineering WORK goes into getting the shape of the blades optimized and locating them to get the best airflow for the lowest operating cost.
Where are they used?
Most heated commercial or industrial buildings can save energy costs with HVLS fans. They are also used in dairy and farm buildings to reduce heat stress on animals. They are most commonly used where ceilings range from 20 to 90 feet high.
Heating Season Savings
The main reason for using HVLS fans is to save on the heating bill. Heat rises up toward the ceiling causing layers of different temperatures in a building. The higher the ceiling is the more the heat rises. It is not unusual for the temperature at the ceiling 20 to 30 degrees hotter than it is down at floor level where people work.
In your heated building, the temperature at the floor may be 65 and at the ceiling, it may be 95. That means you are paying to heat the building to an average temperature of 80.
With a HVLS fan, continually mixing the air, the temperature at floor level might be 65 and at the ceiling, it might be 69 for average of 67 degrees. It costs a lot less to heat a building to a 67 average temperature than it does to heat it to an average of 80 degrees.
For a project that I worked on recently I calculated the savings for a building that had an 85-foot ceiling height. The cost to install two big HVLS fans using high cost union labor will be paid back in one heating season.
Spring and Fall Savings
During the changeable weather in the spring and fall, HVLS fans can save money and increase comfort. Running on slow speed to bring the heat down from the ceiling can delay start up of the heating system in the fall and permit early shut down of the heaters in the spring. Heat from lights and motors is usually enough to keep folks comfortable on cool nights. The fans can be sped up to provide air currents for heat relief on hot days.
By running HVLS fans, at their higher speed, during hot weather folks will feel the breeze they create. This gentle breeze uses the “wind chill” effect to make folks feel cooler. This is when they really pay off for farmers, dairymen and horse stable operators. A cooling breeze reduces heat stress for both people and animals.
Where to get information
Click here for a free money saving report written by the Energy Boomer titled HOW SAVE MONEY ON YOUR NEXT HEATING BILL