Your HVAC system’s variable fan speed is more energy efficient.
Changing your terminal unit’s (HVAC equipment located in thermal zones) fan speed impacts air ventilation. Variable fan speed in HVAC systems significantly reduces energy use. Many terminal units incorporate constant speed fan control which do not house the same ventilation disadvantages. However, constant speed fan control is an enormous waste of energy. Variable airflow units are the most environmentally friendly option. In this week’s blog we’ll explore how, exactly, varying fan speeds impact your HVAC’s systems ventilation capabilities, and provide solutions for keeping your system running efficiently and smoothly.
Fan Speed And Ventilation
The fan within a terminal unit needs to create high enough pressure at the discharge unit in order to account for the loss associated with pushing air through ductwork and diffusers. Fans must create low pressure, as well, to make up for pressure losses experienced when drawing air through return air dampers, filters and coils within the terminal unit. A unit with variable fan speed pushes less air through ductwork, and diffusers, and thus results in less pressure loss. Consequently, less pressure is needed when drawing air through return mechanisms. The amount of pressure directly affects how much outside air enters the HVAC unit. Outside airflow decreases as fan speed reduces. So, the relationship between fan speed and ventilation is directly proportional. As the pressure within the HVAC terminal lowers, the amount of outside air drops as well. As outdoor airflow lowers, fan speed is reduced. With a variable fan speed system, the reduction in fan speed causes a reduction in ventilation.
Why You Need an HVAC Unit With Variable Fan Speed
While yes, variable fan speeds do affect your HVAC system’s ability to function at 100% capacity, there are ways to work around the ventilation issue. For example, adding an airflow-measurement device will help you diagnose how much outside air is missing from your system. Adjustments can be made to rectify this. Varying fan speeds within your HVAC system will significantly lower your facility’s environmental impacts. Saving you a significant amount more on your energy bills than terminal units with constant speed fan control. Install one today, and reward your employees with a company vacation, or new equipment!
Call Crockett Facilities For Energy Savings
Crockett Facilities Services, Inc. (CFSI) is committed to helping building owners, property managers, engineers, and facility professionals lower their operating expenses through HVAC preventive maintenance. We can develop a cost-effective, customized preventive maintenance plan for your commercial building that will provide you with peace of mind, improved comfort, and energy savings.
To learn more about the importance of HVAC Preventive Maintenance, please contact us at 202.600.2787 or sales@crockett-facilities.com. Our PM contract customers receive priority service with 24/7 emergency service in Maryland, Virginia and Washington, DC.