The other day we were on a roof in West Palm Beach Florida to complete a site survey on an Addison RTU (roof top unit). Within the unit there are five coils. This is a very unique outside air unit. Inside, there are three condenser coils, a hot gas reheat coil and a DX evaporator coil. In order to get access to the condenser coils the fan must be removed from the top of the unit and we were required to actually sit inside and get proper measurements and circuiting for each coil. What we found is that there were three separate circuits that all tied into a communal header. In addition to the abnormal three circuit design there were barrel headers on each condenser coil as well as the DX evaporator coil. The DX evaporator coil is manufactured as a three circuit face split, making this a very complex unit using only one single circuit. The hot gas reheat is used for increased de-humidification utilizing the hot gas in the refrigerant system. This was an interesting HVAC unit to measure and we are excited to give you insight into this ADDISON DCA series RTU.