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  1. Air
  2. Microbe and mold control

Microbe and mold control

Features>Air>06. Microbe and mold control

06. Microbe and mold control

Mold often grows on cooling coils in HVAC systems due to moisture condensation and is introduced into the building's indoor air. It is also prevalent on or within wall assemblies if water damage occurs or if there is improper detailing in humid locations like kitchens and bathrooms. Mold spores can cause allergic reactions and respiratory problems that can in some cases be severe.

This feature requires the use of ultraviolet germicidal irradiation (UVGI) devices to manage mold and bacteria on cooling coils as well as inspections for signs of mold outside of the air handling system.

Part 1: Cooling Coil Mold Reduction

In buildings that rely on a mechanical system for cooling, the following method of suppressing mold growth is required:

a) Ultraviolet lamps are employed on the cooling coils and drain pans of the mechanical system supplies. Irradiance reaching the cooling coil and drain pan, including the plenum corners, is modeled.
b) Lamps produce ultraviolet radiation at a wavelength of 254 nm so as not to generate ozone.
c) Lamps have ballasts housed in a NEMA-rated enclosure.
Part 2: Mold Inspections

During WELL Commissioning, the following are inspected:

a) No visible signs of discoloration and mold on ceilings, walls or floors.
b) No signs of water damage or pooling.
Lymphatic
Immune
Integumentary
Respiratory

Applicability Matrix

Core & Shell New Construction WELL Interiors
Part 1: Cooling Coil Mold Reduction P P P
Part 2: Mold Inspections - P P
Commercial Kitchen Education Multifamily Residential Retail
Part 1: Cooling Coil Mold Reduction P P P P
Part 2: Mold Inspections P P P P

Verification Methods Matrix

Letters of Assurance Annotated Documents On-Site Checks
PART 1 (Design)
Cooling Coil Mold Reduction 		MEP Spot Check
PART 2 (Performance)
Mold Inspections 		Auditor Inspection

9

National Air Duct Cleaners Association (NADCA). NADCA White Paper on Ultraviolet Lighting Applications in HVAC Systems. http://nadca.com/sites/default/files/userfiles/documents/2014/bod_final_approved_draft_uv_paper_9-20_-_pdf.pdf. Accessed October 8, 2014.
6.1.b

NADCA's White Paper on Ultraviolet Lighting Applications in HVAC Systems states that to avoid ozone production, use UVC lamps with a wavelength of 254 nm.
11

The National Electrical Manufacturers Association. Enclosures for Electrical Equipment (1000 Volts Maximum). http://www.nema.org/Standards/ComplimentaryDocuments/NEMA-250-2008-contents-and-scope.pdf. Published 2008.Accessed September 15, 2014.
6.1.c

NEMA Standards Enclosures for Electrical Equipment recommends appropriately rated enclosures be used, since ultraviolet light and moisture inside HVACs can damage ballasts.
12

National Center for Healthy Housing and American Public Health Association. National Healthy Housing Standard. http://www.nchh.org/Portals/0/Contents/NHHS_Full_Doc.pdf. Published 2014. Accessed September 15, 2014.
6.2.a

The National Healthy Housing Standard states that building materials shall show no signs of mold.
6.2.b

The National Healthy Housing Standard states that building materials shall show no signs of water damage.
Features>Air>06. Microbe and mold control