Varitec Solutions

What the Schedule Doesn’t Tell You About Fan and Coil Performance

admin — Thu, 27 Aug 2026 19:26:34 +0000

August 27, 2026

6 -10 Minute Read Time

The easiest thing to blame when an air handler comes up short on airflow is the fan.

It has a curve, a scheduled operating point and a motor with enough horsepower. So when TAB measures less air than the schedule calls for, the fan is usually where the finger lands first.

Two air handlers can satisfy the same airflow and cooling-capacity requirements on paper and still behave very differently once they’re operating. — One may spend much of its life comfortably at part load. Another may require more fan energy to overcome pressure losses. One coil may give the designer plenty of room for dehumidification and control. Another may meet capacity while leaving less margin when conditions change.

Both selections can be correct.

They are not necessarily equivalent.

A Fan Selection Is More Than a Design Point

Most fan selections begin with required airflow and static pressure.

Those two conditions establish an operating point on the fan curve — but the fan doesn’t operate independently of the system connected to it.

Loads rise and fall. VAV boxes modulate. Outdoor-air quantities change. Filters load. Economizers open and close. Spaces get used differently than anticipated. As airflow requirements and system resistance change, the fan’s operating point can change with them.

That makes understanding the fan curve important beyond the initial selection.

Air leakage, pressure drop, component selection and installation conditions all influence how the airside system ultimately performs.

There is another consideration behind that curve.

Fans are rated under standardized test conditions in controlled test labs. The installed conditions aren’t always as cooperative.

An elbow close to the inlet, an abrupt transition, limited straight duct or an unfavorable discharge arrangement can affect performance. Even fan rotation relative to the first duct turn can matter.

These installation-related losses are commonly referred to as system effect.

The fan curve isn’t wrong. The fan simply may not be operating under the same conditions used to establish its published performance.

Image Credit: https://www.greenheck.com/resources/blog/understanding-fan-system-effects

Published fan performance assumes standardized test conditions. Installed inlet and discharge conditions can affect actual performance.

The typical field response is understandable, but that is why an airflow problem shouldn’t automatically lead to one response:

Increase the speed.

Before Increasing Speed, Follow the Law – Fan Law

Sometimes increasing fan speed is exactly what needs to happen. It just shouldn’t be automatic.

The fan laws show why:

Airflow ∝ Speed

Pressure ∝ Speed²

Power ∝ Speed³

A 10% increase in fan speed theoretically increases airflow by about 10%, pressure by about 21% and power by about 33%.

That creates two questions:

Where did the additional pressure requirement come from?

And:

Can the motor handle the additional brake horsepower?

A motor selected closely around the original operating point may not have enough capacity for the additional load.

Before adding speed, it’s worth understanding what changed in the system — and whether the fan and motor can support the new operating point.

And one of the first places worth looking is sitting upstream or downstream of the fan.

A Coil Selection Is Also an Airside Decision

Cooling coils tend to be judged first by capacity.

Can the coil meet the sensible and latent load at the scheduled conditions?

It has to.

But the first coil selection that meets capacity isn’t necessarily the right selection for the unit.

During AHU selection, each internal component contributes to the unit’s total pressure requirement. Filters, dampers, coils and other components are configured before the final fan selection is validated.

That means changing the coil can change the fan selection.

A coil may meet capacity but carry more airside pressure drop than another option. A larger coil face may reduce face velocity and pressure drop, but require a larger casing and more first cost. Additional rows may provide more heat-transfer surface while also affecting pressure drop and access for cleaning.

This is where “meets capacity” stops being enough.

TECHNICAL NOTE | Why Face Velocity Matters

Face Velocity = Airflow ÷ Coil Face Area
For the same CFM, a larger coil face means lower face velocity. That can reduce airside pressure drop and help reduce the potential for moisture carryover from a wet cooling coil — but it can also increase AHU size and first cost.

Then there’s the coil five years from now.

Can it be accessed? Can it be cleaned? What happens to pressure drop when the coil and filters no longer look the way they did on startup day?

Those aren’t just maintenance questions.

They’re performance questions.

Capacity tells us whether the coil can meet the load. Face velocity, geometry, pressure drop, controllability and serviceability help determine how well the system performs while doing it.

Design Insight

The best-performing fan or coil isn’t necessarily the one with the highest efficiency. It’s the one that best supports the way the building will actually operate.

There is rarely one “correct” selection.

A hospital may place a premium on humidity control, redundancy and reliability. An office building may prioritize energy performance. Another project may be constrained by footprint, acoustics or first cost.

The goal isn’t to maximize every variable.

It’s to understand which compromises the project is making — and why.

Energy, humidity control, acoustics, redundancy, first cost, serviceability, controls and lifecycle performance all influence what better means for a particular application.

That is what turns equipment selection into engineering.

The Controls Eventually Inherit Those Decisions

Once the AHU starts, the controls system works with the machine that was selected and installed.

It can’t remove pressure drop from a coil. It can’t correct poor fan inlet or discharge conditions. It can’t manufacture fan capacity that isn’t there.

But controls can have an enormous influence on how the available capacity is used.

Consider duct static pressure in a VAV system.

A fixed static-pressure setpoint can ask the supply fan to maintain pressure even when downstream demand has fallen. The VFD makes the pressure. The VAV dampers throttle it away.

Static-pressure reset allows the target to respond to actual system demand.

The question becomes:

How much pressure does the building actually need right now?

The same principle applies to coil control. A coil that satisfies a peak-load calculation still has to be controllable as airflow, water conditions and load change.

Selection establishes the operating envelope. Controls determine how intelligently the system moves within it.

When the Fan Really Is the Problem

None of this means the fan gets a free pass.

If an AHU is short on air, actual fan speed should be compared with commanded speed. Rotation, VFD limits, fan-array operation, motor capability, wheel condition and the measured operating point all deserve verification.

The difference is that by then, we know more.

We know the pressure drop across the filters and coil. We know something about system resistance. We know whether the fan is seeing reasonable inlet and outlet conditions. We know what static pressure the controls are asking it to maintain.

Now, if the fan cannot make the duty, we can say so for a reason.

The Schedule Is the Beginning, Not the Finish Line

Schedules give us a common basis for selection.

Buildings are less cooperative.

Filters load. Dampers actuate. Coils get wet and dirty. Loads change. Components need maintenance. Controls respond to what is happening throughout the system.

That is why the best-performing fan or coil isn’t necessarily the one with the most impressive number on a selection report.

It’s the one that best supports the way the building needs to operate.

Sometimes the consequences of those choices don’t become obvious until TAB is standing in the mechanical room looking for 2,000 missing cfm.

By then, the question is no longer whether the schedule was right.

It’s whether the entire airside system had what it needed to succeed from the start.

And that’s a much easier question to answer during selection than during TAB.

Next month, we’ll bring the pieces together and look at what happens after startup — and why controls, commissioning and serviceability are essential to achieving the performance the design intended.

Air Leakage: Understanding Its Impact on Airside Performance

admin — Wed, 22 Jul 2026 04:09:16 +0000

THE CONDUIT BLOG

July 21, 2026

Equipment Blog | Controls Blog

Coils | Fans | Optimization

7 -10 Minute Read Time

AIR LEAKAGE: UNDERSTANDING ITS IMPACT ON AIRSIDE PERFORMANCE

Every air handling unit is the result of hundreds of design decisions.

Fan selection.
Coil selection.
Cabinet construction.
Damper performance.
Controls integration.
Service access.

Each decision influences the performance of the others.

The challenge is that buildings don’t operate one component at a time—they operate as complete airside systems. Understanding how those individual design decisions affect overall system performance is fundamental to effective airside optimization.

Air leakage is one of the clearest examples of why systems perspective matters. It’s often viewed as a specification buried within an equipment submittal: a cabinet leakage rating, a damper leakage class, or a performance percentage reported during testing. In reality, leakage can influence airflow, building pressure, ventilation, humidity control, controls performance, and energy consumption throughout the life of the system.

The amount of leakage matters, but so does where it occurs and how it affects overall system performance.

The sections that follow examine where air leakage occurs, how it influences overall system performance, and how a systems-thinking approach helps engineers evaluate its impact within the complete airside system.

Why Air Leakage Is Difficult to Diagnose

Unlike a failed fan or a clogged filter, air leakage rarely presents itself as a single, obvious problem. Instead, it often appears as a collection of symptoms that seem unrelated—or point to the wrong cause.

A building may struggle to maintain positive pressure. Outdoor air percentages may drift. Space humidity becomes difficult to control. Occupants report comfort complaints even though the equipment appears to be operating normally.

Because these issues span multiple disciplines, each team may verify that its portion of the system is functioning as intended. The mechanical contractor confirms equipment operation. The controls contractor verifies the sequence of operation. TAB confirms airflow. Commissioning validates system functionality.

As a result, air leakage can remain hidden even when individual components appear to be operating as designed.

Air leakage isn’t simply an equipment specification. It’s a system-performance consideration because its effects can extend well beyond the location of the leak.

To understand those impacts, it helps to first understand where air leakage commonly occurs.

Where Air Leakage Occurs

Not all air leakage has the same impact. Two systems may have similar leakage rates but experience very different operating consequences depending on where the leakage occurs and the pressure conditions within the air handling unit.

Figure 1 highlights the most common leakage paths found within an air handling unit and connected ductwork. Cabinet seams, access doors, dampers, pipe penetrations, field-assembled sections, and duct transitions all have the potential to become unintended leakage paths. While manufacturers evaluate cabinet leakage using standards such as AHRI 1350 and damper leakage using AMCA 500-D, these ratings represent controlled laboratory conditions. Installation quality, commissioning, maintenance, and operating conditions all influence how the system performs in the field.

Cabinet leakage is only one source. Dampers, ductwork, access doors, and field installation details can all influence overall airside performance and should be considered as part of the complete system.

Why Location Matters

The location of a leak often matters as much as the amount of air leaking.

Leaks on the negative-pressure side of the fan allow unconditioned air to enter the system, increasing the amount of air that must be heated, cooled, filtered, humidified, or dehumidified. Leaks on the positive-pressure side allow conditioned air to escape before it reaches the occupied space, reducing delivered airflow and affecting ventilation and building pressure.

Rather than evaluating leakage by specification alone, it should be considered how leakage paths influence the performance of the entire airside system.

Looking Beyond the Specification

The effects of air leakage extend beyond the air handling unit itself. Depending on where leakage occurs and how the system operates, it can influence multiple aspects of HVAC performance.

Energy Performance – Air that enters or escapes the system must often be heated, cooled, filtered, or dehumidified, increasing fan energy and conditioning loads.
Ventilation & Building Pressure – Leakage can make outdoor-air quantities and building pressure more difficult to maintain, particularly in facilities with strict pressurization requirements.
Humidity Control – Unintended airflow can alter latent loads, contributing to humidity drift, condensation, excessive reheat, or dehumidification challenges.
Controls Performance – Control sequences are developed based on expected airflow. When leakage changes how air moves through the system, achieving the intended operating conditions becomes more difficult.
Long-Term Operation – Leakage can contribute to recurring comfort complaints, additional troubleshooting, and increased maintenance throughout the life of the building.

Application	Why Leakage Matters
Commercial Offices	Energy efficiency, occupant comfort, and maintaining outdoor-air ventilation.
Healthcare	Maintaining pressure relationships, ventilation requirements, and humidity control in critical spaces.
Laboratories	Supporting directional airflow and pressurization required for occupant safety and process integrity.
Education	Providing consistent ventilation, occupant comfort, and efficient operation across varying occupancy schedules.
Industrial & Manufacturing	Maintaining process conditions, ventilation effectiveness, and building pressure where operations are sensitive to airflow.

Rather than asking, “How much air is leaking?” ask, “How does that leakage affect the way the system operates?”

Design Insight

Equipment specifications describe individual performance characteristics. Successful airside design depends on how those characteristics work together.

Engineering Tradeoffs: Balancing Leakage and Pressure Drop

Air leakage and pressure drop are separate performance characteristics, but they are often evaluated together during equipment and damper selection.

Air leakage is airflow passing through or around a component where it is not intended.

Pressure drop is the resistance imposed on the intended airflow as it moves through a component.

Design decisions such as casing construction, seals, damper blades, transitions, and other airside components may influence both characteristics. However, a low-leakage product is not inherently a high-pressure-drop product, nor is a low-pressure-drop product inherently leaky. Each characteristic should be evaluated independently using standardized performance data.

This distinction is reflected in industry standards. AMCA 500-D provides separate test methods for damper leakage and pressure drop, while AHRI 1350/1351 separately evaluates AHU casing leakage and other mechanical performance characteristics.

Why the Energy Comparison Matters

Although air leakage and pressure drop are evaluated independently, they influence energy consumption in different ways.

Pressure-Drop Energy

Pressure drop affects all of the intended airflow moving through the system whenever the fan operates. Even a modest increase in pressure drop can increase fan energy because the fan must overcome that additional resistance across the system’s full design airflow for every operating hour.

Leakage Energy

The energy associated with air leakage depends on several factors, including:

How much air leaks
The pressure difference across the leakage path
When the leakage occurs
Whether the air is outdoor, return, exhaust, or conditioned supply air
Whether the fan must move additional air to maintain required airflow
The heating, cooling, and humidity load associated with that air

Depending on the application, air leakage may result in:

Additional fan energy to move replacement airflow
Heating or cooling energy to condition unwanted air
Latent energy associated with humidification or dehumidification
Changes in ventilation performance, economizer operation, or building pressurization

Effective airside optimization requires considering both leakage and pressure drop together rather than attempting to minimize either characteristic in isolation.

A good example is damper selection. In the Southwest, economizers can provide significant hours of free cooling because of cool nighttime temperatures and large daily temperature swings. Capturing those energy savings depends on more than simply opening the outdoor air damper. Low-leakage dampers help maintain intended airflow, building pressurization, and ventilation performance, while pressure drop directly affects fan energy consumption. Focusing on only one characteristic can improve one aspect of system performance while negatively affecting another.

KEY TAKEAWAY

The lowest leakage rate is not always the best solution.

The right balance delivers the best overall system performance.

Engineering Considerations

While every project has different priorities, a few design principles can help ensure air leakage is evaluated as part of the complete airside system—not simply as an equipment specification.

Coordinate Controls with Mechanical Design

Mechanical and controls design should work together to achieve the intended system performance. Economizer sequences, building pressurization strategies, and airflow control all rely on components operating as expected. Even well-designed sequences cannot overcome mechanical limitations such as excessive leakage or improperly selected dampers.

Consider the Application

The appropriate leakage performance depends on the building, occupancy, and operating requirements. A healthcare isolation room, research laboratory, and commercial office may all justify different design decisions based on their ventilation, pressurization, and humidity requirements.

Verification and Troubleshooting

Even the best design should be easy to verify. Providing access for inspection, testing, balancing, and commissioning makes it easier to confirm that the system is performing as intended—not just during startup, but throughout its operating life.

Think Beyond Startup

Air leakage performance isn’t determined on the day the equipment is installed. Maintenance, adjustments, component replacement, and years of operation can all influence how the system performs over time. Designing with long-term operation in mind helps preserve performance throughout the building’s lifecycle.

From Design Intent to Field Verification

When system performance doesn’t match the design intent, air leakage is often overlooked because its effects appear elsewhere. Building pressure may fluctuate, ventilation rates may drift, humidity may become difficult to control, or the BAS may require repeated adjustment—even though the root cause lies outside the control sequence.

A systematic approach can help determine whether unintended leakage is contributing to the problem.

Follow the Pressure

Begin by understanding the pressure zones within the air distribution system. Leaks on the negative-pressure side allow unconditioned air to enter the system, while leaks on the positive-pressure side allow conditioned air to escape before it reaches the occupied space. Knowing where the system is under positive or negative pressure helps narrow the search and connect observed symptoms to potential leakage paths.

Verify the Mechanical System

Before adjusting control sequences, confirm that the mechanical system is operating as intended. Inspect cabinet seams, access doors, duct connections, and penetrations for visible leakage. For dampers, verify blade position, actuator travel, linkage adjustment, end stops, and seals.

Remember, a BAS command of 0% confirms what the controller requested—it doesn’t confirm that the damper is fully closed.

Confirm System Performance

Verification methods should match the application and the suspected leakage path. Smoke pencils, ultrasonic leak detection, airflow measurements, and TAB testing can all help identify suspected leakage or confirm system performance.

When a more quantitative evaluation is required, ASHRAE Standard 215 provides a standardized method for measuring and reporting leakage airflow in operating HVAC air distribution systems, giving engineers a consistent approach for evaluating field performance.

Whether using field observations or standardized testing, the objective remains the same: determine how unintended air leakage influences the performance of the complete airside system.

Safety Note: Any smoke or fog testing should be coordinated with the equipment manufacturer, facility personnel, and fire alarm team before testing begins.

Field Reminder

A closed command confirms what the controls requested—not necessarily what the damper did.

Verifying mechanical movement is just as important as verifying the sequence of operation.

Conclusion

Air leakage is often reduced to a cabinet rating or damper specification, but its influence extends well beyond a single published value. Its impact depends on where leakage occurs, how the system operates, and how it interacts with airflow, ventilation, controls, humidity, and building pressure.

Evaluating air leakage therefore requires more than comparing specifications. It requires understanding how individual design decisions work together to influence the performance of the complete airside system—from equipment selection and installation through commissioning and long-term operation.

The goal isn’t simply to specify the lowest leakage rate. It’s to design an airside system in which every component works together to deliver reliable, efficient, and predictable performance.

Continue the Conversation

Air leakage is only one part of successful airside design. Download our Damper Challenges & Sequence Guide to explore how damper leakage, control sequences, ventilation strategies, and building pressurization work together to influence overall system performance.

Download

download

The information presented in this article is intended to support engineering discussions and should be used in conjunction with applicable project requirements, manufacturer recommendations, and the latest editions of relevant industry standards.

References

AHRI Standard 1350 – Performance Rating of Central Station Air-handling Unit Casings
AMCA Standard 500-D – Laboratory Methods of Testing Dampers for Rating
ASHRAE Standard 215 – Method of Test to Determine Leakage of Operating HVAC Air-Distribution Systems

Humidity Control Technology Selection Guide

admin — Thu, 25 Jun 2026 17:45:44 +0000

THE CONDUIT BLOG

June 25, 2026

Equipment Blog | Controls Blog

Coils | Fans | Optimization

5 – 10 Minute Read Time

Humidity Control Technology Selection Guide

A practical reference to help match humidity control technologies with the right application, performance requirements, and operating conditions.

Selecting the right humidity control technology starts with understanding the application—not the equipment. Required dew point, ventilation rates, moisture loads, available utilities, and energy goals all influence the best solution.

This guide provides a high-level comparison of common humidification and dehumidification technologies. Use the interactive graphics below to explore each technology’s typical operating range, applications, advantages, and limitations.

What's Your Goal?

Remove Moisture or Add Moisture?

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Typical Dew Point Range:<\/strong>
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Best For:<\/strong><\/p>\n
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Offices<\/li>\n
Schools<\/li>\n
General Commercial Buildings<\/li>\n<\/ul>\n\n
Advantages:<\/strong><\/p>\n
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Lowest first cost<\/li>\n
Familiar technology<\/li>\n<\/ul>\n\n
Limitations:<\/strong><\/p>\n
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Limited humidity control at part load<\/li>\n<\/ul>\n\n
Products:<\/strong><\/p>\n
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Daikin Rebel<\/a><\/li>\n
Daikin RTUs<\/a><\/li>\n
AnnexAir<\/a><\/li>\n<\/ul>\n\n<\/div>","hotspot_offset_x":{"unit":"%","size":77,"sizes":[]},"hotspot_offset_y":{"unit":"%","size":64,"sizes":[]},"hotspot_label":"","hotspot_link":{"url":"","is_external":"","nofollow":"","custom_attributes":""},"hotspot_icon":{"value":"","library":""},"hotspot_horizontal":"left","hotspot_vertical":"top","hotspot_tooltip_position":"no","hotspot_position":null},{"hotspot_custom_size":"","hotspot_width":{"unit":"px","size":0,"sizes":[]},"hotspot_tooltip_content":"

DX Cooling

Typical Dew Point Range:
55-50°F

Best For:

Offices

Schools

General Commercial Buildings

Advantages:

Lowest first cost

Familiar technology

Limitations:

Limited humidity control at part load

Products:

Daikin Rebel

Daikin RTUs

AnnexAir

DX + Hot Gas Reheat

Typical Dew Point Range:
50-43°F

Best For:

Schools

Healthcare

Fitness centers

High ventilation applications

Advantages:

Improved humidity control

Reduced overcooling

Products:

Daikin Rebel with HGRH

AnnexAir

Chilled Water

Typical Dew Point Range:
52-42°F

Best For:

Large Commercial Buildings

Healthcare

Higher Performance Facilities

Advantages:

Excellent humidity control

Ideal for central plant applications

Supports a wide range of cooling capacities

Products:

Daikin AHUs

Nortek Custom AHUs

Liquid Desiccant

Typical Dew Point Range:
45–32°F

Best For:

Natatoriums

Dedicated dehumidification systems

High outdoor air applications

Advantages:

Removes moisture independently of sensible cooling

Maintains low dew points under varying load conditions

Ideal for applications with high latent loads

Products:

Mojave

Solid Desiccant

Typical Dew Point Range:
40–0°F

Best For:

Laboratories

Pharmaceutical facilities

Industrial process applications

Advantages:

Achieves ultra-low dew points

Ideal for high latent load applications

Reliable performance in demanding industrial environments

Products:

Munters

Multi-Stage Desiccant

Typical Dew Point Range:
0°F to -150°F dew point

Best For:

Ultra-low dew point applications

Processes requiring moisture levels beyond conventional desiccant systems

Common Applications:

Lithium battery manufacturing

Semiconductor production

Aerospace manufacturing

Research laboratories

Specialty dry rooms

Highly controlled industrial processes

Advantages:

Achieves extremely low dew points

Designed for process-critical moisture control

Maintains ultra-dry environments for sensitive manufacturing

Limitations:

Specialized system design and application

Higher first cost and operating complexity

Typically not used for commercial comfort HVAC applications

Products:

Munters

Selection Starts With…

Before selecting equipment, define:

Target dew point or humidity level

Application requirements

Available utilities (steam, chilled water, water quality)

Operating priorities (first cost, energy, maintenance, control accuracy)

Once these design criteria are established, use the technology guides above and below to compare solutions.

Adiabatic

Typical Capacity:
Medium to High

Typical Humidification Method:
Evaporative (non-steam)

Best For:

Energy-efficient humidification

Facilities with evaporative cooling benefits

Common Applications:

Office buildings

Schools

Warehouses

Manufacturing facilities

Advantages:

Very low energy consumption

Provides evaporative cooling while humidifying

Lower operating costs than steam systems

Limitations:

Requires high-quality treated water

Cooling effect may not be desirable year-round

Greater water management requirements

Products:

Munters

Stulz

Direct Steam Injection

Typical Capacity:
High

Typical Humidification Method:
Boiler steam

Best For:

Facilities with central boiler steam

Large commercial and institutional buildings

Common Applications:

Hospitals

Universities

Industrial facilities

Central utility plants

Advantages:

Fast response to changing humidity loads

High-capacity humidification

Simple when clean steam is readily available

Limitations:

Requires a boiler steam source

Steam quality must be appropriate for the application

Not practical where central steam is unavailable

Products:

DriSteem

Isothermal

Typical Capacity:
Low to High

Typical Humidification Method:
Self-generated steam

Best For:

Precise humidity control

Applications requiring stable room conditions

Common Applications:

Healthcare

Museums and archives

Laboratories

Commercial buildings

Advantages:

Precise humidity control

No cooling effect on the air stream

Available in electric, gas, and steam-to-steam configurations

Limitations:

Higher energy use than adiabatic systems

Requires a steam generation source

Operating costs depend on utility rates

Products:

DriSteem

Key Selection Factors

Start with the Application

Different building types have very different humidity requirements.

Define the Target Dew Point

Dew point—not just relative humidity—determines which technologies are capable of meeting the design conditions.

Understand the Latent Load

Outdoor air, occupancy, and process loads often drive equipment selection more than sensible cooling.

Consider Available Utilities

Steam availability, chilled water, and water quality can eliminate or favor certain technologies.

Evaluate Energy & Operating Costs

The lowest first cost is not always the lowest life-cycle cost.

Plan for Serviceability

Maintenance access, water treatment, and component replacement should be considered early in design.

Need Help Selecting the Right Solution?

Humidity control isn't one-size-fits-all. Our engineering team can help evaluate: design dew point, moisture loads, ventilation requirements, humidification and dehumidification, strategies, and product selection.

Contact the Varitec Team Below

Name

Email

Company

City, State

Message

R-32 and the Future of VRV Systems: What Facilities Teams & Service Contractors Need to Know

admin — Thu, 23 Oct 2025 23:17:40 +0000

THE CONDUIT BLOG

October 23, 2025

4:17 pm

R-32 and the Future of VRV Systems:

What Facilities Teams & Service Contractors Need to Know

The refrigerant transition is not new — it’s already underway. As of January 1, 2025, most commercial equipment began phasing out R-410A in favor of lower-GWP refrigerants.
The next major step is approaching:
VRV systems will transition to R-32 beginning January 1, 2026.
For facility teams and service contractors already supporting VRV, this shift brings meaningful benefits — not additional complexity.

Why R-32 for VRV? A Practical, Future-Ready Choice

R-32 aligns with both regulatory requirements and long-term building performance priorities. It provides higher efficiency, lower environmental impact, and more stable servicing characteristics than the alternatives.
Unlike some refrigerant transitions of the past, this one isn’t about navigating new installation practices or maintenance headaches — it’s about adopting a refrigerant that works with existing VRV field practices.

Key Advantages of R-32 in VRV Systems

1. Single-Component Refrigerant (No Blend Shift)

R-32 is not a blend — which means:
No glide
No component separation during leaks
No remixing or rebalancing during service
Stable performance over the life of the system
This is a major differentiator from R-454B, which can change composition if leakage occurs.

2. Non-Proprietary = Lower Cost and Wide Availability

R-32 is widely manufactured and is not proprietary to any single OEM.
This supports:
Lower refrigerant cost per pound
Broader channel availability
Reduced long-term replacement risk
For facilities planning 20–30 year HVAC horizons, this matters.

3. Lower Refrigerant Charge Requirements

Compared to R-454B, R-32 requires less total refrigerant charge for equivalent system capacity — reducing:
Material cost
Stored volume
Transport and recovery time
Lower charge = lower total lifecycle cost of ownership.

4. Familiar Installation & Service Practices

Most VRV service procedures stay the same:
Same refrigerant piping design and brazing practices
Similar operating pressures
Evacuation and commissioning remain unchanged
The only update: ensure gauges, recovery pumps, and leak detectors are rated for A2L refrigerants.
Most modern R-410A tools already qualify.

5. Built-In Safety & Code Compliance

Daikin VRV systems integrate required A2L safeguards when charge thresholds apply, including:
Refrigerant leak detection
Automated shutoff logic
UL 60335-2-40 & ASHRAE 15-2022 compliant control strategies
Safety is engineered into the system, not added externally.

Preparing Your Team for the VRV R-32 Transition

While certification is not required, we strongly recommend A2L handling training for service personnel. Trusted resources include:
Daikin HVAC Learning Campus
ACCA A2L Safe Handling
NATE Refrigerant Transition Exams

For additional technical guidance, we recommend:
www.R32Reasons.com

Download the A2L Readiness Kit

We’ve put together a concise resource package for facilities & service teams:
A2L Safety & Service Checklist
Tool Readiness Reference
VRV R-32 Transition Key Points
Recommended Training Links

Final Thoughts

The industry is not preparing for refrigerant change — it is continuing it.
With most system categories already transitioned in 2025, VRV moves to R-32 in 2026 as the next step.

R-32 supports:

Lower lifecycle cost

Greater servicing stability

Stronger sustainability alignment

And a clearer long-term equipment roadmap

For facilities teams maintaining VRV systems today, the future is both familiar and improved.

Request More Information and Download Your A2L Readiness Guide

Fill out the form below to request more information and/or get the link to download the guide.

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Title

What would you like to receive? Select all that apply.
VRV Product Info & Pricing Controls Info & Pricing Single Point Power Panel Info & Pricing Service Help Aftermarket Parts A2L Readiness Guide

Select your company type

Varitec Solutions

What the Schedule Doesn’t Tell You About Fan and Coil Performance

The easiest thing to blame when an air handler comes up short on airflow is the fan.

IN THIS ARTICLE

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Why isn’t the fan making its airflow?

What does the fan have to overcome to make that airflow here?

A Fan Selection Is More Than a Design Point

Before Increasing Speed, Follow the Law – Fan Law

Airflow ∝ Speed

Pressure ∝ Speed²

Power ∝ Speed³

A Coil Selection Is Also an Airside Decision

TECHNICAL NOTE | Why Face Velocity Matters

Design Insight

The Controls Eventually Inherit Those Decisions

When the Fan Really Is the Problem

The Schedule Is the Beginning, Not the Finish Line

Before You Add Fan Speed, Check the System​

VFD vs. ECM

Next month, we’ll bring the pieces together and look at what happens after startup — and why controls, commissioning and serviceability are essential to achieving the performance the design intended.

Air Leakage: Understanding Its Impact on Airside Performance

THE CONDUIT BLOG

AIR LEAKAGE: UNDERSTANDING ITS IMPACT ON AIRSIDE PERFORMANCE

The challenge is that buildings don’t operate one component at a time—they operate as complete airside systems. Understanding how those individual design decisions affect overall system performance is fundamental to effective airside optimization.

Why Air Leakage Is Difficult to Diagnose

Where Air Leakage Occurs

Why Location Matters

Looking Beyond the Specification

Application

Why Leakage Matters

Rather than asking, “How much air is leaking?” ask, “How does that leakage affect the way the system operates?”

Design Insight

Equipment specifications describe individual performance characteristics. Successful airside design depends on how those characteristics work together.

Engineering Tradeoffs: Balancing Leakage and Pressure Drop

Why the Energy Comparison Matters

Pressure-Drop Energy

Leakage Energy

KEY TAKEAWAY

Engineering Considerations

Coordinate Controls with Mechanical Design

Consider the Application

Verification and Troubleshooting

Think Beyond Startup

From Design Intent to Field Verification

Follow the Pressure

Verify the Mechanical System

Confirm System Performance

Field Reminder

Conclusion

Continue the Conversation

The information presented in this article is intended to support engineering discussions and should be used in conjunction with applicable project requirements, manufacturer recommendations, and the latest editions of relevant industry standards.

References

Humidity Control Technology Selection Guide

THE CONDUIT BLOG

Humidity Control Technology Selection Guide

A practical reference to help match humidity control technologies with the right application, performance requirements, and operating conditions.

What's Your Goal?

Remove Moisture or Add Moisture?

DX Cooling

DX + Hot Gas Reheat

Chilled Water

Liquid Desiccant

Solid Desiccant

Multi-Stage Desiccant

Selection Starts With…

Adiabatic

Direct Steam Injection

Isothermal

Key Selection Factors

Start with the Application

Define the Target Dew Point

Understand the Latent Load

Consider Available Utilities

Evaluate Energy & Operating Costs

Plan for Serviceability

Need Help Selecting the Right Solution?

R-32 and the Future of VRV Systems: What Facilities Teams & Service Contractors Need to Know

THE CONDUIT BLOG

R-32 and the Future of VRV Systems:

Before You Add Fan Speed, Check the System