1.4.5.4 Dampers in room diffusers and registers shall be used only for
minor balancing requiring a maximum pressure drop of approximately 25
Pa (0.10 inch of water gage). Registers and/or diffusers shall not be
located on main ducts or main branches. They shall be located on
individual branch ducts with opposed blade balancing dampers in the
branch to reduce room noise transmission.
1.4.5.5 Air quantities on plans shall be "rounded off" to the nearest
increment of 0.30 Cu M/Min (10 CFM).
the Electrical Specifications, but the locations at air handling units
shall be shown on the "H" drawing control diagrams and floor plans.
Coordinate diffuser location and blow direction with space detector
locations shown on the Electrical Drawings to avoid false smoke alarms
caused by air discharge.
1.4.5.7 Provide fire dampers and smoke dampers in accordance with
Article 2.13 "Smoke and Fire Protection". Provide a schedule for smoke
dampers showing sizes, pressure drops, and compliance with the maximum
velocity limit. Show duct transitions on drawings.
1.5 HVAC CALCULATIONS, ANALYSES AND REVIEW SUBMITTALS
1.5.1 CALCULATIONS
1.5.1.1 Calculations shall include room by room heat gain and loss;
room by room air balance showing supply, return, exhaust, transfer, and
make-up air quantities; equipment capacities; economic analysis; and
sound and vibration analysis. Calculations and analysis should be
identified, arranged and summarized in proper format. They shall be
indexed in a bound folder with each air handling unit as a zone and
separate chapters for cooling loads, heating loads, exhaust systems,
pumping/piping calculations, fan selections, etc.
1.5.1.2 Heat transfer coefficients, solar radiation, psychrometrics,
duct and pipe sizing, etc., and calculations and analysis shall be in
accordance with the ASHRAE Handbooks and VA Design Criteria.
shall be included in cooling load calculations.
1.5.1.4 In addition to internal loads for people and lights include
heat gain from equipment, such as sterilizers, X-ray, washers, burners,
ovens, refrigerators and dietetic.
1.5.1.5 The use of computer programs and calculations is acceptable and
desirable. Calculations should, however, be keyed to appropriate room,
zone, and unit numbers for each identification.
1.5.2 ECONOMIC ANALYSIS
1.5.2.1 Economic analysis concerning cost of steam generation shall be
based upon fuel cost and boiler plant efficiency. Use plant efficiency
of 75 percent, unless information to the contrary is available. No
labor or maintenance (included in steam cost calculated by the station)
should be included in the cost of additional steam generated. Analysis
HVAC DESIGN MANUAL
1-22
GENERAL REQUIREMENTS
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