1 February 1999
b. Design ventilation systems to maintain positive pressure within the occupied spaces
c. Include provisions for a subslab ventilation system in the design that may later be
required to complete a system to maintain that area at a negative pressure of 1.25 to 2.50 cm
water (0.5 to 1.0 inches water) column at the vent inlet in comparison to the occupied spaces.
One method that has proven to be successful consists of a 10-cm (4-inch) diameter PVC
suction pipe per each 150 m2 (1500 ft2) of slab area. Embed perforated pipe into the aggregate
through the slab and cap the top of the pipe. These vent pipes can later be uncapped and
attached to an exhaust fan if radon mitigation is required after construction. Provide access to
air intake for areas isolated by footings or grade beams.
2-8. CONTROLS. Design HVAC controls in accordance with TM 5-815-3.
2-9. NOISE AND VIBRATION CONTROL. Design HVAC systems with respect to noise and
vibration control in accordance with TM 5-805-4. Use acoustical duct liner only where other
methods of noise control are not feasible.
2-10. SEISMIC PROTECTION. Design HVAC systems with respect to seismic protection in
accordance with TM 5-809-10.
2-11. TESTING, ADJUSTING, AND BALANCING. CEGS 15990 contains many of the
requirements of HVAC testing, adjusting, and balancing. CEGS 15990 contains strict quality
control guidelines that the construction contractor must meet in order to verify that the HVAC
systems have been properly installed and operating as specified. TAB considerations merit
careful attention by the designer to ensure that the customer's needs are met. Few portions of
a typical building require interaction by so many separate components under widely different
operating conditions; therefore it is imperative that the designer address all aspects of TAB
during the design.
2-12. COMMISSIONING. The use of CEGS 15995 is mandatory for all Air Force projects and
its use is encouraged for all projects. Note that use of CEGS15995 requires funding for the
designer or a representative of a designer to participate in the commissioning at the project site.
Commissioning is intended for all appropriate contractor and customer (typically a
representative of the Department of Public Works or the Base Civil Engineer) personnel and the
designer to demonstrate that the HVAC systems have been properly installed and operate as
intended by the designer and that the systems will satisfy the customer's. Another tangible
benefit is that the customer has the opportunity to become familiar with the operation of the
HVAC systems. Commissioning is not intended to be used in lieu of any tests specified by
2-13. REFRIGERANTS. Carefully review the current version of the appropriate CEGS prior to
the selecting mechanical refrigeration equipment. Current and anticipated future restrictions
limit or prohibit the use of ozone-depleting substances. Where refurbishment or demolition of
mechanical refrigeration equipment is involved, provide detailed step-by-step guidance and
diagrams that comply with the recommendations of ASHRAE Guideline 3 for this work.
2-14. SPECIAL CRITERIA FOR HUMID AREAS. Use the following criteria in the design of air-
conditioned facilities located in areas--