Choosing the right heat exchanger does not have to start with a long technical specification or a complicated engineering calculation.

For many standard heating and cooling applications, you can start with a few basic operating parameters and quickly determine what type of heat exchanger you may need.

Our free heat exchanger selection tool is designed for engineers, contractors, OEMs, plant operators, purchasing teams and anyone who needs a fast preliminary heat exchanger solution.

Enter your operating conditions, get a preliminary selection, and then submit the results for a detailed engineering review.

Start with your actual operating data—not a guess based on heat exchanger size or price.

What Do You Need to Select a Heat Exchanger?

A heat exchanger cannot be selected correctly from heat duty alone.

For a preliminary selection, the most important information normally includes:

• Hot-side fluid
• Cold-side fluid
• Hot-side inlet temperature
• Hot-side outlet temperature
• Cold-side inlet temperature
• Cold-side outlet temperature
• Flow rate
• Heat duty, if already known
• Maximum allowable pressure drop
• Operating pressure
• Design pressure
• Fluid concentration
• Fluid viscosity
• Fouling conditions

These parameters determine the thermal and hydraulic requirements of the equipment.

Commercial heat exchanger selection tools commonly use these same types of inputs, including fluid properties, temperatures, flow rates and allowable pressure drop.

How the 1-Minute Heat Exchanger Selection Works

The basic process is simple.

Step 1 — Select the Heat Exchanger Application

Choose the type of service:

• Water-to-water heating
• Water-to-water cooling
• Glycol heating or cooling
• Oil cooling
• Process heating
• Process cooling
• Condensing
• Evaporating
• HVAC
• Industrial heat recovery

The application determines which heat exchanger construction and materials may be suitable.

Step 2 — Enter the Two Fluids

Select or enter the fluid on each side.

For example:

Hot side: Process water

Cold side: Cooling water

Or:

Hot side: 30% propylene glycol

Cold side: Chilled water

If the fluid is not pure water, provide the concentration whenever possible.

Fluid properties can have a significant effect on heat transfer and pressure drop.

For viscous liquids, for example, the same flow rate can produce very different hydraulic conditions compared with water.

Step 3 — Enter the Four Temperatures

Enter:

Hot inlet

Hot outlet

Cold inlet

Cold outlet

These four temperatures establish the basic temperature program.

For a typical liquid-to-liquid application:

The selection calculation uses these temperatures to determine the available temperature driving force.

For many heat exchanger calculations, the log mean temperature difference (LMTD) is used to represent the effective temperature difference across the exchanger.

Step 4 — Enter the Flow Rate

Enter the flow rate for one or both sides.

Common units include:

• m³/h
• L/min
• kg/h
• kg/s
• GPM
• lb/h

If the flow rate is known, use the actual design flow rather than an approximate value.

For variable-flow systems, provide the normal, minimum and maximum flow where possible.

Flow rate affects both:

Heat transfer performance

and

Pressure drop

Therefore, the correct flow rate is essential for a useful selection.

Step 5 — Enter Heat Duty if You Know It

If the required heat duty is already known, enter it directly.

Typical units include:

• kW
• MW
• BTU/h
• TR
• kcal/h

If heat duty is not known, it can often be calculated from flow rate, specific heat and temperature change for single-phase fluids.

A basic relationship is:

Q = ṁ × Cp × ΔT

where:

• Q = heat duty
• ṁ = mass flow rate
• Cp = specific heat capacity
• ΔT = fluid temperature change

The duty calculated from one side should be reasonably consistent with the duty on the other side after accounting for measurement and process differences.

For condensing or evaporating applications, however, latent heat and enthalpy must also be considered. A simple sensible-heat equation is not sufficient for every application.

Step 6 — Enter the Maximum Allowable Pressure Drop

This is one of the most important inputs in heat exchanger selection.

Do not simply leave pressure drop out of the calculation.

A heat exchanger may achieve the required heat duty with a very small unit if a high pressure drop is allowed.

But that may increase pump power.

Conversely, requiring an extremely low pressure drop may require:

• More heat transfer area
• More plates
• Larger channels
• Different plate geometry
• Larger connections
• A larger heat exchanger

Therefore, heat transfer and pressure drop must be evaluated together.

For plate heat exchangers, the number of plates and flow configuration are selected to meet the required thermal duty while staying within the available pressure drop.

What Does the Free Heat Exchanger Selection Tool Give You?

A preliminary selection tool can help you identify:

• Recommended heat exchanger type
• Estimated heat transfer capacity
• Preliminary heat transfer area
• Approximate number of plates
• Flow arrangement
• Estimated pressure drop
• Suitable material options
• Preliminary model or model range
• Basic operating limits

This gives you a starting point for equipment selection.

It is especially useful when you need to compare different heat exchanger options quickly.

Why You Should Not Select a Heat Exchanger by kW Alone

A common request is:

“I need a 500 kW heat exchanger. What model should I buy?”

That information is not enough.

Two applications can both require 500 kW, but require completely different heat exchangers.

Consider these two cases.

Application A

• Water
• 20 m³/h
• 80°C → 50°C
• Cooling water 20°C → 40°C

Application B

• 40% glycol
• 20 m³/h
• 80°C → 50°C
• Cooling water 20°C → 40°C

The heat duty may be similar, but glycol changes fluid properties and hydraulic behavior.

The required heat exchanger design may therefore be different.

The same principle applies to:

• Oil
• Seawater
• Refrigerants
• High-viscosity liquids
• Corrosive fluids
• Food products
• Chemical solutions

Heat duty tells you how much heat must be transferred.

It does not tell you the complete equipment design.

What Determines the Final Heat Exchanger Size?

The final selection normally depends on several parameters working together.

Heat Duty

How much heat must be transferred?

Temperature Difference

How much temperature driving force is available?

Flow Rate

How much fluid must pass through the heat exchanger?

Fluid Properties

What are the density, viscosity, specific heat and thermal conductivity?

Pressure Drop

How much pressure loss can the system tolerate?

Fouling

How likely is the heat transfer surface to become contaminated?

Materials

What plate, tube, gasket or brazing material is compatible with the fluid?

Operating Pressure and Temperature

What mechanical design limits must the equipment withstand?

A proper heat exchanger selection balances all of these factors rather than optimizing only one.

Plate Heat Exchanger Selection: What Matters Most?

For a plate heat exchanger, selection typically involves determining:

• Plate material
• Plate pattern
• Plate size
• Number of plates
• Channel arrangement
• Number of passes
• Connection size
• Gasket material
• Heat transfer area
• Pressure drop

Increasing the number of plates generally provides more heat transfer area, but it can also affect pressure drop, size and cost.

The plate pattern also influences the balance between heat transfer and hydraulic resistance.

Therefore, the lowest-cost plate configuration is not automatically the best engineering solution.

Brazed Plate Heat Exchanger Selection

A brazed plate heat exchanger is commonly considered for compact applications where a gasketed frame is not required.

Typical applications include:

• HVAC
• Heat pumps
• Refrigeration
• Oil cooling
• Hydronic systems
• Water heating
• Industrial cooling

For brazed plate selection, pay particular attention to:

• Fluid type
• Flow rate
• Inlet and outlet temperatures
• Operating pressure
• Maximum pressure drop
• Fouling risk
• Brazing material
• Refrigerant conditions where applicable

Because brazed plate heat exchangers generally cannot be opened in the same way as gasketed plate-and-frame units, fouling conditions should be considered carefully during selection.

Why Pressure Drop Can Change the Recommended Model

Suppose you need:

500 kW heat transfer

A calculation may show that several configurations can achieve the duty.

But they may have different pressure drops.

For example:

The technically best option depends on the available pump head and the operating economics.

This is why a selection tool should not simply return the smallest heat exchanger that can theoretically transfer the required heat.

It should consider the thermal and hydraulic requirements together.

What If You Do Not Know All the Parameters?

You do not always need a complete engineering datasheet to start.

If you do not know the heat duty, you may be able to calculate it from:

Flow rate + inlet temperature + outlet temperature + fluid properties

If you do not know the flow rate, it may sometimes be calculated from the required duty and temperature change.

If some fluid properties are unavailable, the fluid name and concentration may allow an initial estimate.

However, missing information should not simply be replaced with arbitrary assumptions for a final equipment selection.

The more complete the input data, the more reliable the result.

Free Preliminary Selection Is Not the Same as Final Engineering Design

A one-minute selection tool is useful for preliminary sizing and product selection.

It should not be treated as a substitute for a final manufacturer rating.

A final heat exchanger design should verify, as applicable:

• Heat duty
• LMTD
• Heat transfer coefficient
• Flow velocity
• Pressure drop
• Fouling allowance
• Materials
• Design pressure
• Design temperature
• Operating range
• Mechanical limitations
• Applicable codes and standards

A preliminary calculator can quickly narrow down the possible equipment.

The final manufacturer selection should confirm that the proposed unit actually meets the project requirements. Engineering selection tools from major manufacturers similarly use detailed operating inputs rather than capacity alone.

Get Your Preliminary Heat Exchanger Solution in 1 Minute

If you already know your operating conditions, you can start with the following information:

1. Hot-side fluid

2. Cold-side fluid

3. Hot-side inlet temperature

4. Hot-side outlet temperature

5. Cold-side inlet temperature

6. Cold-side outlet temperature

7. Flow rate

8. Maximum allowable pressure drop

9. Operating pressure

10. Fluid concentration, if applicable

Enter the available information into the free heat exchanger selection tool to obtain a preliminary solution.

Then submit the calculation results to our engineering team for confirmation.

We can review the operating conditions and determine whether the preliminary selection is suitable for the actual application.

Need a Heat Exchanger Selection for Your Project?

If you are replacing an existing heat exchanger or designing a new system, you do not need to guess the model from a catalogue.

Send us:

Fluid → Flow rate → Inlet temperature → Outlet temperature → Operating pressure → Allowable pressure drop → Heat duty

If available, also provide:

Fluid concentration → Viscosity → Fouling conditions → Design pressure → Design temperature

With these parameters, a preliminary heat exchanger selection can be prepared quickly, followed by a detailed thermal and hydraulic check.

Use the free heat exchanger selection tool to get started.

Enter your operating conditions and get a preliminary heat exchanger solution in about 1 minute.