Retrotec USACE - Manual (Page 161)

Appendix D D31
D.2.3 HVAC Distribution Systems
D.2.3.1 No Duct and Piping Insulation (Waste)
Figure D51. Uninsulated heating duct.
Heated or cooled air and water is used in HVAC systems to control tempera-
ture within occupied spaces. The heating or cooling is achieved by using energy
to create the temperature increase or decrease. The heated or cooled air and
water is conveyed through ducts or pipes to the intended location. To maintain
the temperature of the air or water, insulation is used to stop loss or gain of the
temperature. When inadequate insulation is used on ducts or pipes warmer
than 51.7 °C (125 °F) or cooler than 15.6 °C (60 °F), this will result in excessive
energy loss (Figure D51).
D.2.3.2 Inoperable Dampers (Waste)
Figure D52. Inoperable dampers.
Dampers are used in supply and return air ductwork to control air fl ow to hab-
itable spaces and provide outdoor ventilation air to the occupants in the spaces.
Some of these dampers modulate as the HVAC system operates in response to
varying loads or as the system is turned on and off. When these dampers do not
operate correctly, uncontrolled air fl ow can occur, which causes excessive use
of energy to cool or heat unnecessary outdoor air (Figure D52).