MIL-HDBK-1011/1
Increase insulation thicknesses as required to maintain surface temperature
above dewpoint of ambient air.
a) Insulate all chilled water, refrigerant suction, and condensate
drain lines, including valves, strainers, and fittings when possible. Ensure
that all valve stems, gauge stems, and control sensor stems are also
insulated.
b) Provide a vapor barrier and coatings for all cold piping 60
degrees F and lower. Ensure that pipe insulation vapor-barrier jacket is
factory-applied.
Give special attention to the details of construction and to
the specifications for the vapor barrier to ensure complete moisture and vapor
seal where insulation terminates against metal hangers, anchors, and other
projections through insulation on cold surfaces with vapor barriers.
c) Require that the ends of pipe insulation be sealed with a
vapor-barrier coating at valves, flanges, and fittings and at intervals not to
exceed 15 feet on long pipe runs. Goat joints of pipe insulation with vapor-
barrier coating compound to ensure vapor seal of insulation sections.
d) To the maximum extent possible, install chilled water piping in
accessible locations to allow for replacement of old, deteriorated insulation.
Avoid installing chilled water piping in concealed, non-air conditioned
spaces, including ceilings to minimize condensation problems.
e) Provide an aluminum or stainless steel jacket on insulated
piping located outdoors.
f) Use pre-insulated piping for buried chilled water, steam, and
other underground piping requiring insulation.
14.10.4
Ductwork Insulation. Insulation thicknesses for ductwork specified
in NFGS-15250 are also based on 85 degree F dry bulb and 85 percent relative
humidity ambient air. Ensure insulation thicknesses specified will maintain
surface temperature of insulation above ambient dewpoint in instances where
the actual ambient temperature and humidity exceed the above conditions.
Insulate all supply and return air ductwork.
a)
b) Provide insulation with vapor barrier and coating.
c) Use internal duct liner insulation in exposed outdoor ducts
when possible or where there is a lack of quality installation expertise for
external insulation/vapor barrier on ductwork.
d) Insulate exhaust ducts passing through concealed spaces which
exhaust conditioned air, and provide with a vapor barrier in areas where the 1
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