5.13 Thermal Insulation
Accessories such as adhesives, mastics, cements, tapes, etc.
shall have the same or better component ratings. All
supply air ducts must be insulated, in accordance with
ASHRAE Standard 90.1. Supply air duct insulation shall
have a vapor barrier jacket. The insulation shall cover the
All insulation materials shall comply with the fire and
duct system with a continuous, unbroken vapor seal.
smoke hazard ratings (25 for flame spread; 50 for smoke
Return air and exhaust air distribution systems shall be
developed) as indicated by ASTM-E84, NFPA 255 and UL
insulated in accordance with ASHRAE Standard 90.1. The
723. Accessories such as adhesives, mastics, cements and
insulation of return air and exhaust air distribution
tapes shall have the same or better fire and smoke hazard
systems needs to be evaluated for each project and for
Insulation shall be provided in accordance with ASHRAE
heat gain/loss on a recirculating or heat recovery system.
Standard 90.1. Insulation that is subject to damage or
Generally, return air and exhaust air distribution systems
reduction in thermal resistivity if wetted shall be enclosed
do not require insulation if located in a ceiling plenum or
with a vapor seal (such as a vapor barrier jacket).
mechanical room used as a return air plenum. All
equipment, heat exchangers, converters and pumps shall
Duct Insulation. All exposed ductwork shall have sealed
be insulated as per ASHRAE Standard 90.1.
canvas jacketing. All concealed ductwork shall have foil
Piping Insulation. All insulation material shall comply
with the fire and smoke hazard ratings indicated by
The insulation shall comply with fire and smoke hazard
ASTM-E84, NFPA 255 and UL 723. Accessories such as
ratings indicated by ASTM-E84, NFPA 255 and UL 723.
adhesives, mastics, cements, tapes, etc. shall have the same
or better component ratings. All piping systems must be
insulated in accordance with ASHRAE Standard 90.1.
Piping systems conveying fluids having design
temperatures less than 18.3C (65F) or greater than
40.6C (105F) shall be insulated. All piping systems with
surface temperatures below the average dew point
temperature of the indoor ambient air and where
condensate drip will cause damage or create a hazard shall
formation regardless as to whether piping is concealed or
exposed. Chilled water piping systems shall be insulated
with nonpermeable insulation (of perm rating 0.00) such
as cellular glass. All exposed and concealed piping shall
have PVC jacketing.
Air Flow Diagram, Atrium, Phoenix Courthouse
150 F A C I L I T I E S S T A N D A R D S
5.13 Thermal Insulation
Revised March 2005 PBS-P100