Chiller & Boiler Pump Location – Upstream or Downstream? Let’s Settle This Debate One of the recurring questions I hear from engineers, operators, and even contractors on site is: 👉 “Should pumps be located upstream or downstream of chillers and boilers?” At first glance, it feels like a simple “rule-of-thumb” answer. But in reality, it’s a nuanced design decision guided by hydronic principles, ASHRAE handbooks, and equipment manufacturer limits. Let’s break it down 👇 🌡️ Chilled Water Systems Low- to Mid-Rise Buildings: Pumps are often placed upstream of the chiller evaporator (on the return side). ✅ Benefits: Pump heat is absorbed by the chiller, positive NPSH margin, and evaporator stays flooded. 🔎 Backed by: Trane Engineers Newsletter & ASHRAE guidance. High-Rise or Pressure-Limited Plants: Pumps are placed downstream of the chiller evaporator (on the supply side). ✅ Benefits: Prevents adding pump head across the chiller tubes (protects pressure rating). ❌ Drawback...
Duct & Chilled Water Pipe Insulation System Materials Density Thickness Vapor Barrier Duct Insulation - Glasswool <br> - Rockwool <br> - Phenolic Foam <br> - Elastomeric (NBR/EPDM) 24 – 48 kg/m³ - 25 mm (≤ 65 mm dia) <br> - 38 mm (65–150 mm dia) <br> - 50 mm (>150 mm dia) Aluminum foil or kraft paper laminate CHW Pipe Insulation - Pre-formed rigid fiberglass <br> - Rockwool <br> - Elastomeric foam (Armaflex) — - 25 mm (General) <br> - 38 mm (65–150 mm dia) <br> - 50 mm (>150 mm dia) Required for all cold pipes (to prevent sweating & energy loss) ⚡ Quick Notes for QC/Inspection: Always check material type, density, and thickness against specifications. Ensure vapor barrier is intact on all cold ducts and pipes. Insulation must be continuous and sealed properly at joints to avoid condensation. hashtag # HVAC hashtag # DuctInsulation hashtag # ChilledWater hashtag # MechanicalEngineering hashtag # BuildingServic...