6.3.2.15.Evaporative Heat Rejection Systems

(1) Evaporative heat rejection systems shall (a) incorporate a drift eliminator or other means to minimize the dispersion of entrained water droplets, and (b) have a design discharge velocity that does not exceed the maximum discharge velocity recommended by the manufacturer. (2) Evaporative heat rejection systems shall be designed so that water continuously circulates through all parts of the system that are normally wetted when the system is operating. (3) Evaporative heat rejection systems and their components shall be constructed of corrosion-resistant, non-porous materials that do not promote the proliferation of disease-causing micro-organisms and that are compatible with disinfectants, biocides and other cleaning agents. (4) Evaporative heat rejection systems shall be installed such that (a) no discharge air bypasses the drift eliminator or other means referred to in Clause (1)(a), and (b) the systems are accessible for cleaning, inspection and maintenance. (5) Except as provided in Sentence (6), air discharged from evaporative heat rejection systems shall discharge away from the building, so as to not re-enter it, to a distance not less than (a) 2.15 m above sidewalks and driveways, (b) 7.6 m from outdoor air intakes, (c) 3 m horizontally or vertically from exterior doors and operable windows, and (d) 3 m horizontally or vertically from occupiable outdoor spaces, excluding maintenance spaces. (See Note A-6.3.2.15.(5) and (6)) (6) Air discharged from evaporative heat rejection systems in health care facilities shall discharge away from the building in compliance with CAN/CSA-Z317.2, “Special requirements for heating, ventilation, and air-conditioning (HVAC) systems in health care facilities.” (See Note A-6.3.2.15.(5) and (6)) (7) Air intakes of evaporative heat rejection systems shall incorporate protective measures to minimize the entrainment of vegetation and other organic matter. (8) Make-up water connections shall be equipped with backflow prevention devices that conform to Article 7.6.2.1. (See Note A-6.3.2.15.(8) and (9)) (9) Water treatment systems and equipment for controlling the proliferation of disease-causing micro-organisms shall (a) be provided in accordance with Section 7.6.2. of ASHRAE Guideline 12, “Minimizing the Risk of Legionellosis Associated with Building Water Systems,” and (b) include means for drainage, dilution, cleaning, and application of chemicals for the control of scale, corrosion and biological contamination. (See Note A-6.3.2.15.(8) and (9)) (10) Drains, overflows and blow-downs shall be connected to the building's drainage system in accordance with Clause 7.4.2.1.(1)(d). (11) Evaporative heat rejection systems shall be provided with access openings, service platforms, fixed ladders and fall- restraint connections to allow inspection, maintenance and testing.