The United States market has come a long way on embracing ductless HVAC units. From 20 years ago when you would occasionally see a unit installed on a sunroom to present day when this technology is regularly used to combat discomfort in bonus rooms, additions, garages, and even whole home applications. Along the way code has had to change in order to adapt to the more widely used ductless technology. One of these areas of adaption is in the protection of a wall mounted indoor unit from condensation overflow. Unlike traditional installations where auxiliary drain pans are widely used, the standard wall mounted indoor unit only has the internal drain pan. This design leaves open the possibility of wall and/or flooring damage should the drain line become obstructed.
Beginning in the early 2000’s International Residential Code (IRC) as well as International Mechanical Code (IMC) began to update their code requirements to include proactive measures for protecting homes against condensate overflow:
M1411.3.1.1 Water-level monitoring devices. On down-flow units and all other coils that have no secondary drain or provisions to install a secondary or auxiliary drain pan, a water-level monitoring device shall be installed inside the primary drain pan.
IMC 307.2.3.1 Water-level monitoring devices. On downflow units and all other coils that do not have a secondary drain or provisions to install a secondary or auxiliary drain pan, a water-level monitoring device shall be installed inside the primary drain pan. This device shall shut off the equipment served in the event that the primary drain becomes restricted. Devices installed in the drain line shall not be permitted.
There is a wide selection of devices that can be used to protect internal drain pans from overflow as well as protect condensate pumps from overflow should the pump or the line itself become obstructed. The key to using these devices and the common challenge faced by contractors is ensuring the devices are properly wired for the specific system being used. Often I take phone calls for communication issues created during installation of drain safety or pump. In worst case scenarios damage can take place to some of the
To help educate our customers and to attempt preventing issues, ECMD has added “how to” videos on the installation of drain safety devices for both our Daikin and Gree brands of ductless units.
Check out our Pro Training videos for more videos on ductless wall mounted installation and maintenance.
