Retro-Commissioning (RCx), sometimes referred to as Existing Building Commissioning (EBCx), is an important process for optimizing the performance of existing buildings. It involves the comprehensive evaluation of a building’s systems, their components, and how they interact with each other. The goal of RCx is to identify areas of improvement in the building’s operation maintenance, [...]
Laboratories, whether in a college/university, medical building, or research facility, are one of the highest energy-consuming functions in any building. Lab spaces require large amounts of outside air, have high air change rates, and in many cases strict space temperature and humidity requirements. The HVAC systems that serve these spaces typically operate 24/7, 365 [...]
When a multi-zone variable air volume (VAV) air handling system is designed, you might notice that the scheduled leaving air temperature of this unit is about 55°F. Why is that? The 55°F setpoint is based on the typical cooling space temperature and relative humidity (RH) setpoints commonly needed in buildings, which typically ranges from [...]
When designing a building’s heating hot water system, determining the peak heating hot water supply temperature is a critical decision. These systems provide heat to air handling systems, perimeter radiation, radiant panels, fan coil units, reheat VAV boxes and other hydronic heating elements. The hot water supply temperature (HWST) must be high enough to [...]
Implementing and Effective Demand Control Ventilation Strategy When an air handling system is designed, ventilation air requirements are one of the most important aspects. The amount of outside airflow (ventilation) required for a system is dependent on how the space is used. Does the air handling unit serve a gymnasium or an office building? [...]
Imagine being in your home on a breezy, cool day. You’re cooking in the kitchen, kids are running around the house, and next thing you know, everyone is feeling a bit warm. What do you? Most people would open windows to cool down the house before turning on their home air conditioning system. This, [...]
Converting a Single Zone Air Handling System to Variable Air Volume Control In the 1880s, Nikola Tesla invented and was granted a patent for his three-phase, alternating current induction motor, a device that was leaps and bounds more dependable than the direct current motors of the time. However, it was not until nearly the [...]
Remove the Brakes on Your Pumps by Installing VFDs It is quite commonplace to find variable frequency drives (VFDs) installed on pumps in any new construction or retrofit project and of course, they are necessary for any type of variable volume pumping system. However, VFDs can also be utilized on constant flow pumping systems. [...]
HVAC System Trim & Response Resets When a building is newly constructed, one of the last steps performed on the HVAC system is the testing, adjusting, and balancing (TAB). The purpose of TAB is to verify the design air and water flows are properly supplied throughout the building. One of the most critical components [...]
Before the days of advanced control systems, buildings would be preheated or precooled prior to occupancy using a standard warm up or cool down mode of operation. These primitive sequences would start the air handling units at a set time interval before the building entered into occupied mode. The air handling unit would then [...]
