Q. As I read the Mechanical Code, Paragraph 307.2 Evaporators and cooling coils: “Condensate drain systems shall be provided for all equipment and appliances containing evaporators or cooling coils.” I am not aware of any exceptions for chilled beams. What is the latest on this?
This is a good question that is being asked a lot lately. It’s also a timely question as a revision has recently been made to the code.
No, drain pans are not required in chilled beams that provide sensible only cooling.
Please see three attached documents:
IMC Code Change Recognizes Dry Coil Use in Chilled Beam Design
“The International Mechanical Code (IMC) approved a code change proposal from the Air-Conditioning, Heating, and Refrigeration Institute’s (AHRI) Chilled Beam Product Section to remove the requirement for condensate drains for certain chilled beam designs.”
“The code now includes an exception to Section 307.2 for dry evaporators or cooling coils, which are designed to operate in sensible cooling only and are not designed to support condensation.”
The change has been enacted. It missed the 2012 IMC publication and will be incorporated in the 2015 publication. The IMC changed the code by petition from AHRI’s Chilled Beam section, which voted unanimously to pursue the change.
Chilled beams were developed in Europe as an energy savings device. They are used in systems where all latent cooling is done at the main air handling unit at significant cost savings. Dry air is delivered to chilled beams where sensible cooling brings temperature to design. In Europe drain pans are not used.
We’re glad for this code change. Why would you want to put a drain pan where you don’t need it? The extra cost of piping is a waste and shouldn’t be a part of a green solution.
Related Manufacturer Link: Swegon