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Florida Water StarSM Technical Manual

Indoor criteria

HVAC Cooling Tower

HVAC cooling tower.

Appliances

Commercial heating, ventilation, and air-conditioning (HVAC) cooling towers

Background

Significant amounts of water can be used in a building’s heating, ventilation, and air-conditioning (HVAC) system.

HVAC cooling towers are typically used on buildings greater than 10,000 square feet and may comprise a large portion of a commercial and institutional project’s water use. Multiple efficiency practices exist that can significantly conserve water across the lifetime of a cooling tower system.

Requirements and certification

HVAC cooling towers must comply with the following practices:

HVAC Water Efficiency
Adapted from Green Plumbing and Mechanical Code Supplement
(Source: International Association of Plumbing and Mechanical Officials [IAPMO])

  • Use the lowest-quality water supply available.
  • Prohibit the use of once-through cooling using potable water.
  • Equip cooling towers and evaporative coolers with makeup water and blowdown meters, conductivity controllers and overflow alarms.
  • Shall be equipped with efficiency drift eliminators that achieve drift reduction to 0.002% of the circulated water volume for counterflow towers and 0.005% for cross-flow towers.
  • Operate on not less than five cycles of concentration is required for air-conditioning cooling tower makeup water having a total hardness of less than 11 grams per gallon (gr/gal) (188 milligrams per liter [mg/L]), expressed as calcium carbonate.
  • Operate on not less than 3.5 cycles of concentration is required for air-conditioning cooling tower makeup water having a total hardness equal to or exceeding 11 gr/gal (188 mg/L), expressed as calcium carbonate.

Exception: Air-conditioning cooling tower makeup water having a discharge conductivity rate less than 7 gr/gal (120 mg/L) to 9 gr/gal (154 mg/L) of silica measured as silicon dioxide.

Silver

Gold

Commercial/Institutional

NA

NA

Required

Installation must be field-verified by the certifier.

St. Johns River Water Management District
4049 Reid Street, Palatka, FL 32177
800-725-5922