SCOPE OF WORK: HVAC Water Treatment & Maintenance 1. Project Objective HACLA requires a qualified contractor to provide comprehensive monthly water treatment, chemical supply, and semi-annual cleaning for the building’s critical cooling and heating infrastructure. The primary goal is to prevent scale, corrosion, and biological growth (specifically Legionella) while maintaining peak equipment efficiency. 2. Equipment Inventory System Component Quantity Capacity/Brand Type Cooling Towers (Server) 2 50-Ton (BAC) Open & Closed Loops Cooling Tower (Building) 1 350-Ton (Marley) Open Loop Chiller (Small) 1 80-Ton (Carrier) Closed Loop Chiller (Large) 1 278-Ton (Daikin) Closed Loop Heating Boiler 1 Raypak Hi Delta Closed Loop 3. Standard Service Requirements • Hours of Operation: Monday – Friday, 8:00 AM – 4:00 PM (excluding holidays). • Coordination: All service must be scheduled 48 hours in advance with the HACLA Building Engineer. • Compliance: All services must meet ASHRAE Standard 188-2015 and 2026 California Public Works labor standards. 4. Technical Specifications A. Open Loop Systems (Cooling Towers) Frequency: Monthly 1. Chemical Management: Supply and apply all chemicals to inhibit scale, corrosion, slime, and algae. 1. Note for Building Tower: A Dual Biocide Program (Oxidizing + Non-Oxidizing) is mandatory. 2. Water Chemistry Analysis: Test makeup and recirculating water for Calcium Hardness, M-Alkalinity, Chlorides, Iron, Conductivity, and pH. 3. Equipment Calibration: Clean sensors and recalibrate automatic controllers and feeders monthly. 4. Biological Testing: 1. Monthly: Dip slide tests. 2. Quarterly: One (1) Heterotrophic Plate Count (HPC) analyzed via SM9215B Protocol at a State Certified Lab. 3. Semi-Annual/Annual: Mandatory Legionnaires’ Disease Testing. B. Closed Loop Systems (Chillers & Boilers) Frequency: Monthly 1. Inhibitor Levels: Maintain Sodium Nitrite at 800 – 1,200 PPM. 1. High Temp Rule: If Boiler exceeds 185°F, increase levels to 1,000 – 2,000 PPM. 2. Corrosion Control Targets: 1. Conductivity: < 3,500 micromhos/cm 2. pH Range: 8.5 – 10.5 3. Copper: < 0.2 PPM | Iron: < 2.0 PPM 3. Centrifugal Separator Maintenance: Execute a comprehensive plan for cleaning, lubrication, and record-keeping per manufacturer guidelines.
