The secondary heat exchanger or “reheat coil” is almost always located directly above the blower making them prone to collecting more dust and debris than air conditioning coils. This is why it is imperative to access, inspect and clean these coils in order to properly clean the system.Jun 2, 2015
What is a reheat VAV?
Variable air volume (VAV) with reheat systems provide conditioned airconditioned airAir conditioning, often abbreviated as A/C or AC, is the process of removing heat and controlling the humidity of air in an enclosed space to achieve a more comfortable interior environment by use of powered "air conditioners" or a variety of other methods, including passive cooling and ventilative cooling.https://en.wikipedia.org › wiki › Air_conditioningAir conditioning - Wikipedia to each zone at a constant temperature, typically 55°F. The amount of air varies to match the heat gain from equipment, lights- exterior and people. ... A damper (such as a pre-manufactured VAV box) adjusts airflow at each zone.
How does a reheat valve work?
HOT GAS REHEAT uses the high pressure, high temperature, compressor discharge gas to reheat the air leaving the evaporator coil. This is achieved by running the gas through a hot gas reheat coil using hot gas reheat valves.Feb 19, 2020
How do you size a reheat coil?
- Main Heating Coil Airflow = 500 cfm.
- Leaving Coil Temperature = 122.3 F.
- Entering Coil Temperature = 55.9 deg F.
- Main Heating Coil Capacity = (1.0882) x (500) x (55.9 - 122.3) = -36,128 Btu/hr = -36.1 MBh.
- Reheat Coil Airflow = 500 cfm.
What's a reheat coil?
1. In an air-conditioningair-conditioningThe air that serves a space and has had its temperature and/or humidity altered to meet design specifications.https://encyclopedia2.thefreedictionary.com › Conditioned+airConditioned air - Encyclopedia system, a coil which heats air in the supply duct to control its temperature. 2. A coil which is heated to control the temperature of air being furnished to individual zones, 1.
Why is it necessary to put reheat coils in VAV boxes?
Reheat is used sometimes for humidity control, and sometimes for occupant comfort. The latter use happens when zone cooling loads are low and too much cold air is supplied to a space. In a VAV system, a damper modulates the amount of cool air supplied to the zone.Sep 14, 2009
Why do you preheat a coil?
In an air-conditioningair-conditioningThe air that serves a space and has had its temperature and/or humidity altered to meet design specifications.https://encyclopedia2.thefreedictionary.com › Conditioned+airConditioned air - Encyclopedia system, a coil used to preheat air which is below freezing to a temperature somewhat above freezing, in advance of other processing.