The Ultimate Guide to Cooling Tower Selection
CogenS™ – Hydronics MFG Selector
Optimizing for Lifecycle Value, Not Just First Cost
The cooling tower is the final, critical checkpoint for heat rejection in any large-scale cooling system. Its performance directly impacts the efficiency of the entire chiller plant and the facility’s overall operational budget. Making the right selection is a long-term commitment, yet many decisions are still driven by the lowest initial purchase price—a critical error that overlooks the true, multi-decade financial and environmental impact.
An improperly selected cooling tower can become a major drain on resources, leading to excessive energy and water consumption, high maintenance costs, and premature failure.
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Effortless Software for a Complex Problem
Objectively Evaluate, Model and Select between Multiple
Cooling Tower System Vendor Products
CogenS™ – Hydronics MFG Selector is an advanced technoeconomic modeling tool engineered to prevent these costly oversights. It provides engineers, contractors, and facility managers with a powerful platform to conduct a rigorous, data-driven analysis of multiple cooling tower manufacturers, ensuring the final selection is optimized for the lowest total cost of ownership (TCO) and peak performance throughout its lifecycle.
What is CogenS™ - Hydronics MFG Selector?
CogenS™ is a powerful, unbiased modeling platform that allows users to run multi-scenario technoeconomic analyses across a range of cooling tower manufacturers and technologies (including open-circuit and closed-circuit designs). By inputting your project’s specific data—including building cooling load profiles, local weather data, and complex utility and water rates—you can simulate how different cooling towers would perform in your specific environment.
The tool processes these inputs to deliver clear, actionable outputs, including:
A ranked selection of options based on the lowest Total Cost of Ownership.
Detailed annual projections for energy use, and fan power energy.
Key financial metrics like Net Present Value (NPV), Internal Rate of Return (IRR), and payback period.
CogenS™ replaces cumbersome and error-prone spreadsheets with a standardized, defensible methodology for making high-stakes capital equipment decisions.
How It Works
Upload your facility's cooling load profiles, local utility rates, and climate data to create a detailed digital twin of your operating environment.
Input the technical data from all cooling tower vendors under consideration, including thermal performance data, fan and pump horsepower, and all capital costs.
The tool simulates each manufacturer's system across the entire project lifecycle, using consistent conditions for a fair, data-driven comparison.
Instantly view tabulated results comparing TCO, energy use, emissions, and financial returns. Identify the most efficient and financially sound system with confidence.
Technical Specifications
Induced-draft and forced-draft cooling towers
Open-circuit and closed-circuit configurations
Counterflow and crossflow designs
Single-cell and multi-cell systems
Hybrid and water-conserving designs
Heat Rejection Load Profiles: Hourly condenser heat loads
Weather Data: Dry bulb and wet bulb hourly data
Utility Costs: electricity rates
Manufacturer Specs:
Capacity vs. ambient conditions
Fan power and VFD behavior
Drift losses
Maintenance schedules
Installation and lifecycle cost estimates
Up to 15
- Efficiency at part and full load
- Multi-unit operation
- Minimum part-load ratio
- Emissions and fuel use
- CAPEX and OPEX
Total Cost of Ownership (TOC): Over a user-defined horizon (10–30 years)
Annual Fuel and Energy Use: For electricity, gas, or hybrid configurations
Operating and Maintenance Costs: Based on usage and unit design
Carbon and Criteria Emissions: With optional carbon pricing
NPV, and IRR: Full financial metrics for decision-making
Degradation Impact: On performance and costs over time
Side-by-Side Comparison Table: Results for all manufacturers entered
Excel
Available via CogenS™ local install
CogenS™ Hydronics MFG Selector Project Design Process
Project Info
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Location.
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Building Type (Industrial, Commercial or Residential).
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Microgrid components (Combined Heat and Power, Combined Cooling Heat and Power, Energy Storage and PV).
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Modeling interval (15, 20, 30 and 60 minutes).
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Metric VS Imperial Units.
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Weather Data.
Energy Profiles
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Building energy profiles Estimation and Analysis (Electric, Gas, Oil, Cooling, Heating, Domestic Hot Water).
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Fuel specifications (Heating Value and Density).
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Scenario Analysis Option (Maximum, Average and Minimum Load Profiles)
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Peak, Minimum, Average Demand and Load Factor.
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Grid Emissions Factor.
Energy Cost
Electric and Gas Utility Tariff
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Fixed and minimum charges.
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Rates Escalation.
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Unlimited Energy and Demand charges by Period and Tier.
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5 Different Metering and Billing Types:
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Net Energy Metering
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Net Energy Metering with $ Credits
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Net Billing
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Net Billing with Carry Over to next Month
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Buy All/Sell All
Oil Cost
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Fixed and minimum charges.
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Rates Escalation.
Cooling
Chillers
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Equipment modeling features:
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Screw, Centrifugal, Scroll and Reciprocating compressors.
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Water- or air-cooled condenser.
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Electric or Gas-Fired absorption.
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Indirect Hot Water or Steam absorption.
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System modelling features:
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Identical multi-unit system.
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Variable or Constant Flow.
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Supply Temperature Reset.
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Part-Load Efficiency Performance.
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Optimized number of operating units.
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CO2e emissions.
Cooling Towers
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Equipment modeling features:
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Open or closed loop.
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Cross or Counter flow.
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Single, 2-speed or variable speed fan.
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System modelling features:
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Identical multi-unit system.
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Free Cooling Heat Exchanger option.
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Wet-Bulb Reset Control Scheme.
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Variable or Constant Flow.
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Supply Temperature Reset.
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CoolTools or YorkCalc Heat Rejection Performance.
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Optimized number of operating units.
Results
Summary
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Energy, Financial and Emissions savings.
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Financial KPIs
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Project Capital and Operating Activities pie charts.
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Conventional VS Cogeneration Pie charts:
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Energy Bill and Consumption by fuel.
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Gas Consumption by fuel.
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Electricity production and emissions by equipment.
Tables
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Lifetime profiles for key project variables in tabular format:
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Sub hourly
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Hourly
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Daily
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Weekly
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Monthly
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Yearly
Plots
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Lifetime profiles for key project variables in plot format:
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Sub hourly
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Hourly
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Daily
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Weekly
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Monthly
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Yearly
Core Benefits at a Glance
Why use CogenS™ for your next Cooling Tower procurement decision?
Who Should Use It?
This modeling platform is indispensable for any professional involved in the design, purchase, or management of Cooling Tower systems.
Deliver true value engineering by moving beyond first-cost. Use CogenS™ to validate your system design, compare technologies (e.g., crossflow vs. counterflow), and provide clients with a clear, data-backed recommendation for the most cost-effective solution.
Make an ironclad business case for capital expenditures. Justify cooling tower replacements and upgrades with detailed ROI projections that clearly illustrate the long-term savings from investing in high-efficiency, low-maintenance equipment.
Conduct sophisticated energy audits with unparalleled accuracy. Use CogenS™ reports to validate projected savings for performance contracts, green building certifications (like LEED), and corporate ESG initiatives.
Differentiate your bids by offering a sophisticated total cost of ownership analysis. Build trust and win more projects by demonstrating long-term value to your clients.
Protect your investment by ensuring the mechanical systems in your portfolio are optimized for low operational costs and long-term sustainability, making your properties more valuable and marketable.
Food for thought Why a Data-Driven Approach to Cooling Tower Selection is Critical
In an era of rising energy costs and increasing water scarcity, a cooling tower’s long-term performance is far more important than its initial price tag. A comprehensive analysis must account for real-world operating conditions, strict efficiency standards, and all associated lifecycle costs.
Performance Certification and Real-World Efficiency
How can you be sure a cooling tower will perform as the manufacturer claims? The Cooling Technology Institute (CTI) provides a vital service through its CTI STD-201 certification program, which validates that a specific model line performs in accordance with its published ratings. Purchasing a CTI Certified tower provides a baseline assurance of thermal performance. However, this certified rating is at a single design point. CogenS™ takes this a step further by modeling how that tower will operate across a full spectrum of real-world conditions, providing a true picture of annual energy consumption.
Navigating Water Consumption and Conservation
A cooling tower’s primary function relies on evaporation, making water consumption a major operational expense and environmental consideration. Key factors like cycles of concentration, blowdown rates, and drift all impact water usage. As detailed in best practices from the U.S. Department of Energy, optimizing these cycles is crucial for efficiency. The CogenS™ platform allows you to model these variables to project long-term water costs and select a tower that aligns with your facility’s water conservation goals.
Meeting and Exceeding ASHRAE Efficiency Standards
ASHRAE Standard 90.1 sets the benchmark for energy efficiency in commercial building systems, including specific minimum performance requirements for cooling towers. Choosing a tower that simply meets the baseline standard can be a short-sighted decision. The CogenS™ tool enables you to compare the lifecycle cost of a standard-efficiency tower against a high-efficiency model, often revealing that the energy savings from the more efficient unit provide a rapid and compelling return on investment.
Start modeling and make the smart, sustainable choice.
Choosing the right cooling tower can save thousands in energy costs and maintenance — and reduce emissions for years to come. Download CogenS™ – Hydronics MFG Selector for free and gain the ability to model, compare, and select the best-performing cooling tower solution for your next project.
Understanding Cooling Tower Systems
A cooling tower system plays a critical role in heat rejection for HVAC and industrial applications. It removes waste heat from chilled water systems, process loops, or cogeneration units by transferring it to the atmosphere through evaporative or dry cooling methods. Selecting the right cooling tower impacts system efficiency, water use, noise, and lifecycle cost.
Key Considerations in Cooling Tower Selection
Thermal Performance: How well the unit cools process or condenser water, especially at design wet bulb temperatures.
Water Consumption: Makeup water requirements, drift losses, and blowdown rates are major OPEX drivers.
Energy Use: Fan power and pump head directly impact operational cost.
Footprint and Noise Levels: Essential for urban and roof-mounted applications.
Maintenance and Materials: Corrosion resistance, fill material, and basin design influence reliability and service life.
Regulatory Compliance: Increasing focus on Legionella risk mitigation, plume control, and noise.
CogenS™ – Hydronics MFG Selector allows you to model multiple tower options using project-specific data — enabling confident, lifecycle-accurate system selection.
🔬 Powered by Engineering Economics
CogenS™ – Hydronics MFG Selector uses finite horizon total investment analysis, a well-established method for evaluating equipment over a defined project life. It goes beyond initial purchase price to account for:
Energy and fuel costs
Emissions penalties
Maintenance intervals
Performance drift
Inflation and utility price escalation
With CogenS™, every equipment selection becomes a transparent engineering decision — not just a guess.
