Webinar

Modular Chillers: Performance & Design Tips for Engineers

This on-demand webinar gives practical guidance on selecting and applying modular chillers, heat pump chillers, and modular HVAC systems.

Webinar Details

Date: April 14, 2026

What You’ll Learn

How modular chillers behave under varying loads—and the pitfalls engineers should avoid
Key hydronic considerations such as loop volume, flow rate, pump control, and thermal mass
Best practices for staging, sequencing, and part load performance
How  modular heat pump chillers support decarbonization goals through electrified heating
Applying air-source (AXM) vs. water-source heat pump technology
When to use 4-pipe, 6-pipe, or multipipe modular systems (like MAS and MWS)
How to integrate modular heat pumps into hybrid or existing chiller plants

Why Trane® Thermafit™ Modular Chillers?

Engineers looking for system flexibility, part load efficiency, and performance consistently turn to the Trane® Thermafit™ Modular System. Designed to address real-world commercial HVAC constraints, Thermafit equipment scales seamlessly, supports redundancy, and delivers strong performance across a wide range of operating conditions.

Core Advantages

Modular scalability: Add capacity in smaller increments to match project phasing, load diversity, or budget constraints.
Improved redundancy and uptime: Multiple modules reduce single point of failure risk versus larger, single body chillers.
Compact footprint: Ideal for tight mechanical rooms, roof placements, and retrofit situations.
Flexible system configurations: Supports cooling only, heating only, and simultaneous heating and cooling depending on model.
Supports electrification & sustainability goals:  Air‑to‑water heat pumps and water‑to‑water heat pump chillers help lower carbon emissions while delivering efficient performance

With proven performance across thousands of installations, Trane® modular chillers are engineered to deliver performance and efficiency—no matter the building type or climate conditions.

Speakers

Daniel Gentry

HVAC Systems Application Engineer Trane®

Dan specializes in chiller plants, heat recovery systems, heat pump applications, and data center HVAC design. With Trane® since 2018, he brings deep technical expertise and a strong engineering foundation, holding a bachelor’s degree in HVAC Engineering Technology from Ferris State University.
John Sustar

Systems Product Manager Trane®

John has been in the HVAC industry since 2009, with broad experience in energy modeling and electrical, mechanical, and hydronic system design. His focus is on helping engineers apply modular HVAC technologies successfully in real-world environments.
Kevin Padnes

Chillers Product Manager Trane®

Kevin leads the Thermafit™ Modular Chiller portfolio, offering a comprehensive range of air-source and water-source heating and cooling solutions—including chillers, heat pumps, and multipipe systems.

FAQs

Your questions about the Thermafit® Modular Chillers, answered.

Can existing chilled-water coils be used for preheating in a new 2-pipe changeover heat pump system?

Yes, in many cases chilled-water coils be used for preheating in a new 2-pipe changeover heat pump system. However, because hot water temperatures are often lower in heat pump systems, deeper coils may be required to achieve the needed heating performance.

What are the low-ambient operating limits for these modular heat pump systems?

Trane provides performance data down to -18°F outdoor ambient. Modular heat pumps will not start below -18°F, but if a unit is already operating and the temperature drops lower, it can continue to operate down to -22°F.

What were the test conditions for Thermafit® modular chiller operation at -18°F?

Thermafit® modular units were tested in an ambient controlled lab at -18°F outdoor ambient while producing 120°F hot water. For additional details, refer to the Trane modular AXM/MAS heat pump application guide (APP-APG021B).

Are supplemental boilers always needed with modular heat pump systems?

No, supplemental boilers are not always needed with modular heat pumps. In warmer climates, supplemental boilers are often unnecessary. In colder climates or in applications with higher leaving-water-temperature requirements, they may still be beneficial depending on the system design and operating profile.

Trane Thermafit® AXM vs. Trane Thermafit® MAS: How do these modular heat pumps differ?

Model AXM can control to either a chilled-water setpoint or a hot-water setpoint.
Model MAS can control to both chilled-water and hot-water setpoints at the same time.
In terms of capacity grouping:
- Trane MAS supports up to 10 modules per bank.
- Trane AXM supports up to 12 modules per bank.

Heat pump cost vs. traditional chiller + boiler system cost: How do these system compare?

In general, a heat pump system may have a higher upfront cost than a traditional chiller + boiler system, but it can deliver lower operating cost depending on utility rates, climate, and building load profile. Because those factors vary widely, lifecycle comparisons should be evaluated on a project-specific basis.

When does it make sense to do a heat pump retrofit on a chiller-boiler system?

Heat pump retrofits often make sense when the existing equipment is 15 to 20+ years old, experiencing reliability issues, when a major renovation is already planned, when electrification or carbon-reduction goals are driving the project, or when the economics support lifecycle payback.

Can Thermafit® units be used for temporary conditioning during construction?

Yes. Thermafit® units are commonly used for temporary building conditioning during construction. As always, proper installation and startup procedures should be followed.

What happens if the Thermafit® chiller system is not installed per manufacturer recommendations?

If the Thermafit® chiller system is not installed in accordance with Trane recommendations, that noncompliance will be documented during startup. Trane startup is required for Thermafit® chillers.

Are split-system air-to-water heat pump options available for freeze protection?

No, split-system air-to-water heat pump options are not available at this time.