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Cooling Load Pipe Sizing Pump Head Duct Sizing BOQ + PDF Export Cooling Tower
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01 Location
02 Room
03 Envelope
04 Sensible & Latent
05 Results

Location & Climate Data

Auto-loaded from ASHRAE 2021 · CIBSE · Carrier HAP · BMD · Local Standards

Climate Selection
🌍
—
—
✏ Override

Room Parameters & Ventilation

🌬 Fresh Air & Ventilation — ASHRAE 62.1 / EN 15251 / CIBSE Guide A
Leave blank to use room area above
Ventilation Design Inputs

Building Envelope

ASHRAE CLTD/CLF Method — Carrier HAP Data

🏗 ASHRAE U-VALUE PRESETS — Select to auto-fill all rows | Edit manually anytime
Source: ASHRAE Handbook of Fundamentals 2021 · ASHRAE 90.1-2022 · All values in BTU/hr·ft²·°F
Solar Gain — Glass (BTU/Hr = Area × SHGF × U)
DirectionArea (SqFt)SHGF / ΔTU-ValueBTU/Hr
Glass Solar Subtotal0
Walls & Roof — CLTD Method (BTU/Hr = Area × CLTD × U)
ElementArea (SqFt)CLTD (°F)U-ValueBTU/Hr
Wall & Roof Subtotal0
Transmission — Partition, Floor, Ceiling, Glass
ElementArea (SqFt)ΔT (°F)U-ValueBTU/Hr
Other Trans. Subtotal0

Sensible & Latent Heat — Internal Loads

Dynamic calculation — change any value to update instantly

👤 People Heat Gain ASHRAE Table 1 — Heat Gain from Occupants
Sensible: 0 BTU/Hr  |  Latent: 0 BTU/Hr  |  Total: 0 BTU/Hr
💡 Lighting Heat Gain ASHRAE Table 2 — Heat Gain from Lights
Sensible: 0 BTU/Hr  |  (Radiant: 0 + Conv: 0)
🔌 Equipment Heat Gain ASHRAE Table 5/6 — Office & Process Equipment
Equipment Total: 0 BTU/Hr  |  Motor: 0 BTU/Hr
⚙ Safety & Diversity Factors

Cooling Load Results

Grand Total Heat
—
Tons of Refrigeration (TR)
Sensible Capacity
—
TR
Supply Air Flow
—
CFM / L/s
Total BTU/Hr
—
BTU/Hr

🌡 Room Sensible Heat

Subtotal: 0 BTU/Hr
Safety Factor: 0 BTU/Hr
Effective RSH: 0 BTU/Hr

💧 Room Latent Heat

Subtotal: 0 BTU/Hr
Safety Factor: 0 BTU/Hr
Effective RLH: 0 BTU/Hr
🌬 Outside Air Heat
0 BTU/Hr
0 BTU/Hr
0 BTU/Hr
0 BTU/Hr
0
0 CFM
—
0

✅ Recommended Equipment

Chilled Water Pipe Size Calculation

Formula: GPM = TR × 2.4 (1 TR = 2.4 GPM, fixed)  |  Carrier Friction Chart  |  Rule: ≤2" → 4 FPS; >2" → 4 ft/100ft

Pipe Sections — Enter TR load per section

🔗 Refrigerant & Chilled Water Pipe Sizing

VRF Refnet Joint (Independent & Modular) · Chiller Pipe Selection · All sizes in inches

Enter total downstream IDU capacity
Independent Main Pipe — Full Selection Table
Sl No Total Capacity Range (Downstream IDUs) Liquid Pipe Size (mm) Liquid Pipe Size (in) Gas Pipe Size (mm) Gas Pipe Size (in) Match
Multi-Section Refnet Calculator
Add multiple refnet joints (e.g. Joint 1, Joint 2...)
Carrier Chart 3 Data — Schedule 40 (All pipe sizes)
Nominal Size OD (in) ID (in) Max GPM @ 4 FPS
(≤2" rule)		 Max GPM @ 4 ft/100ft
(>2" rule)		 Velocity @ 4ft/100ft (FPS) Application Match

💧 Pump Head Calculation

Carrier Tables 10/11/12 · ASHRAE 90.1 · BNBC — Equivalent Length Method

Pipe ΔP = Direct input (ft WG)  |  Fitting ΔP = Friction × Equiv.Length/100 (Carrier T10/11/12)  |  Section Total = Pipe ΔP + Fitting ΔP  |  Pump HP = GPM × TDH / (3960 × η)
Typical CHW: 20–30 ft
Typical: 10–20 ft
2-way valve: 8–15 ft
Typical: 65–80%
PIPE SECTIONS
Pump Selection Summary
0
Total Head (ft WG)
0
Total Head (m WC)
0
Flow (GPM)
0
Motor HP
0
Motor kW
0
Head (kPa)

🏭 Cooling Tower — Make-Up Water Calculation

ANSI/ASHRAE/IES 189.1 · Carrier Engineering Data · CTI Standards

FORMULAS — ASHRAE / SIIT
① Drift Loss
= 0.001% to 0.005% × C
C = Circulating flow (USGPM)
Ref: ASHRAE Standard 189.1
② Evaporation Loss
= 0.001 × C × ΔT
ΔT = Hot inlet – Cold outlet (°F)
Ref: ASHRAE (2000) / ScienceDirect
③ Blowdown Loss
= Evap Loss ÷ (COC − 1)
COC = Cycles of Concentration
Total = Drift + Evap + Blowdown
System Inputs
Leave blank = auto calc from TR
Typical: 3–6. Higher = less blowdown
= 98.6 °F
= 89.6 °F
Temperature Unit:
Cooling Tower Selection
Total cells in system
Typical: 85–92%
Typical: 70–80%
🌡 DESIGN TEMPERATURES — Enter manually or auto-filled from above
Leaving chiller condenser
Returning to chiller
Ambient design WB
Leave blank = auto calc
Typical CT loop: 50–80 ft
= Outlet − Wet Bulb
= Inlet − Outlet
Auto-linked from TR input
Step-by-Step Working (ASHRAE / SIIT Method)

🌬 Duct Sizing Calculator

ASHRAE Fundamentals 2021 · Carrier System Design Manual · SMACNA — Equal Friction / Velocity Method

ASHRAE typical: 0.08–0.12 in.wg/100ft
Standard: 0.075 lb/ft³ @ 70°F
🔵 Supply Main: 700–1200 fpm / 0.08–0.12 in.wg/100ft 🟡 Supply Branch: 500–800 fpm / 0.06–0.10 in.wg/100ft 🟢 Return Main: 600–1000 fpm / 0.08–0.12 in.wg/100ft ⚪ Exhaust: 500–800 fpm / 0.06–0.10 in.wg/100ft
DUCT SECTIONS
Section Type Airflow (CFM) Length (ft) Fittings EL (ft) Head Loss
in.wg/100ft		 Round Ø (in) Rect Area (in²)
= W × H		 Lock Width W (in) Height H (in) Velocity (fpm) Actual HL
in.wg/100ft		 Section ΔP
in.wg		 Status
Total ΔP
—
in.wg
Fan Static Pressure
—
in.wg (×1.15)
Max Velocity
—
fpm
Longest Run
—
ft
Noise Risk
—
velocity check

📋 Bill of Quantities (BOQ)

HVAC Equipment & Material Quantity Schedule — ASHRAE / BNBC

Active Currency: BDT — ৳ Rate Column Header: Unit Rate (৳) Total (৳)
# Category Description Specification / Size Remarks / Notes Unit Qty Unit Rate Total

📁 Saved Projects

All saved calculations — click to load, edit or download PDF

🔍 HVAC System Analysis

Analyze system performance, detect faults, calculate efficiency & get improvement recommendations

🧊 CHILLER
🌊 COOLING TOWER
💧 PUMPS
CHW Pump
CW Pump
Operating Hours