HVAC Clean Air Test and Balance - On Demand

TRAINING INCENTIVES

U.S. MID-ATLANTIC UTILITIES: 

Visit the utility O&M training portal site for eligibility, terms and conditions and pre-approval

• Potomac Edison  (100% Enrollment covered)
• BGE |  Pepco | Delmarva | SMECO (100% Enrollment covered)

 
This course was recorded from a live webinar that may include discussions from attendees. 

Providing Required Airflow to Conditioned Spaces for Comfort and Health

This course explains and shows how to test and adjust the airflow in commercial heating, ventilating, and air conditioning (hvac) systems. For the health and comfort of the building’s occupants hvac systems must provide the correct amount of airflow into and out of conditioned spaces to ensure acceptable temperature, humidity and volume of cooling, heating, and ventilation air.

Recently there have been discussion about changes to percent of outside air (OA) aka fresh air, air changes per hour, and room pressurization in buildings. The amount of ventilation air (outside air) was at one time approximately 10%.  This means that the mixed air going into and through the HVAC filters, cooling coils, heating coils, and into the conditioned space as supply air was  90% return air volume and 10% OA volume. As energy costs increase there is a push-pull between energy management and indoor air quality. An increase in energy cost means the cost to heat and cool the OA goes up. On the energy management side, when energy cost increased the percent of OA was lowered In some buildings to 5%

And buildings were built tighter, with non-operable windows and we had sick building syndrome in the 1980’s and 90’s. Then the OA percentage went back to 10-15%, and sometimes higher, 20% OA. Whatever the amount of ventilation air is required for a particular system and time it is the test and balance people that test and set that requirement.

 Office buildings are typically designed for 5 to 10 air changes per hour (ACH). With less than 5 ACH occupants may complain that the air is stuffy or that they detect body or equipment odors. More than 10 ACH may cause drafts and occupants, especially workers seated at a desk, may feel cold air movement across their bodies. Many hvac engineers design for 7.5 ACH. Medical authorities have called for more air changes per hour in office buildings, schools, etc.

 In some buildings room pressurization may be a critical factor. An example is a hospital where the operating rooms must have a positive room pressure and intensive care units (ICUs) may require a negative pressure. Other buildings with special conditioned spaces that require either a negative or a positive pressure are labs and clean rooms facilities. The typical office has a slight positive pressure and room pressure is not tested.

 In this course you will learn about testing and balancing the ventilation air, the return air, and the heated and cooled supply air for each conditioned space’s air volume in cubic feet be minute (cfm), air changes per hour (ACH) and room pressurization and how to make changes when required. Whether it is conditioned space air volume, air changes per hour, or pressurization it is test and balance professionals that do the testing and make changes.