Vav Box Reheat Coil Sizing

Model tss terminals provide variable air volume vav control beyond the typical single duct box.

Vav box reheat coil sizing. The vav box is supplying air near 55f and not reheating to meet the temperature setpoint. It appear that the coil is not being sized for the reheat load and only for whatever exterior load exists which is none. A one row coil for a size 12 air valve will operate at the above conditions as follows. For example the maximum rating of a vav box for a general office with a desired nc level of 30 should be no more than nc 35.

4 5 6 7. Here is my sizing zone object c fakepath capture png. Electric reheat box was selected the minimum cfm would be dependent upon the kw of the electric heater. They also offer improved space comfort and flexibility for a wide variety of hvac applications.

The zones with lesser cooling demand will throttle their vav boxes down as far as their minimum flows and if the air is still too cold will then reheat the air using a hot water or electric resistance coil at each zone. Summarizes a detailed analysis of vav box control and selection1 and provides vav boxes sizing criteria that will mini mize lcc in typical applications. Sizing and selection of vav terminal units. Vav controls and airflow setpoints figure 1 shows a single duct vav box using pressure independent control logic.

Two or more vav boxes can be controlled with one temperature sensor. Usually inlet diameter determines vav box size. Here is my sizing system object c fakepath capture1 png. Zone with its vav box wide open maximum air flow to the zone.

Imho hvac equipment sizing is 90 engineering and 10 art. If one vav box cannot meet noise criteria consider using two. Trane has developed a computer program to perform these tasks. Compact size and easy access for service saves time and expense in installation rectangular discharge opening is designed for slip and drive cleat duct connection inlet sizes.

Our fan powered terminal units available as parallel and series provide operating cost savings through reduced central fan horsepower and use of waste heat recovery. They are specifically designed for precise air delivery throughout the entire operating range regardless of the installed inlet conditions. Daikin s single duct vav boxes from 80 to 8000 cfm provide high performance and set the standard in the industry for construction performance and quality. Pressure independent controls use two cascading control loops.