ASHRAE 62.1 Standard for Ventilation for Acceptable Indoor Air Quality provides recommendations for minimum ventilation rates and other parameters to ensure good indoor air quality (IAQ). Keeping the IAQ at a safe level will help to minimize any adverse health effects caused by air quality factors.
The 62.1 standard is intended for both new building and building addition projects. It can also be used as a guide for the improvement of IAQ in existing buildings.
In order to properly conform to the ASHRAE 62.1 standard, it is necessary for sensors to be both stable and accurate. Continue reading “How is Stability Related to ASHRAE 62.1 Standards?”
High duct-static pressure creates problems during a building fire when fire dampers close. Closed fire dampers cause downstream duct sensors to detect a drop in pressure. The duct pressure sensors in turn send signals to crank the air handler even faster to get back up to normal operation. Because the fire dampers are closed, when the air handler ramps up, the duct pressure upstream of the fire dampers will increase to a point where a high static pressure switch will cut power to the VFD (variable frequency drive) and send a signal to the DDC (direct digital control). Switches in this application — by specification — are all manual reset and require two outputs: one for cutting power to the VFD and one for sending the signal to the DDC.
