Split-Coil Case Study

HeatEX Technologies • May 7, 2026

Split Coil Solutions for Tight-Space Installations

Redefining How Replacement Coils Are Built and Installed

Replacing coils in older air handlers or equipment rooms with limited access often turns into a costly, labor-intensive challenge. Full-size coils may not fit through existing access doors, stairwells, or hallways—forcing contractors to cut walls, remove louvers, or rent cranes. These complications drive up project costs and downtime. Our split coil design solutions provide a smarter alternative that allows contractors to bring in the coil in sections, assemble it on-site, and restore system operation quickly—without compromising performance, integrity, or operating pressure.

Traditional Split Coil Design

Conventional split coils are typically divided by fin length and joined internally with divider plates and gaskets. While effective in maintaining fluid separation, this approach presents two main drawbacks: - Higher fabrication and field labor costs due to internal divider plates, gaskets, and hardware. - Operating pressure limitations since gasketed divisions restrict system pressure ratings.

Our Simplified Split Coil Options

We engineered two practical alternatives that eliminate the need for divider plates and simplify the field installation process—ideal for contractors working in tight mechanical rooms, basements, or rooftop units with restricted access.

Option 1: Split by Fin Height (Top and Bottom Coil)

A single coil is divided horizontally, creating a top and bottom section. How It Works: The coil’s supply and return headers are fabricated with precision couplings designed to align both sections during installation. Once the coils are set in position, the top and bottom headers are welded or brazed shut, completing the assembly and restoring a continuous circuit. Technical Considerations: Depending on the model or coil geometry, the main connection points may shift slightly between the original and split versions. Minor field repiping adjustments may be required to align the coil’s supply and return lines with existing piping. These adjustments are minimal and typically performed within standard installation practices.

Applications: Ideal for vertical units or air handlers with height restrictions. Perfect for installations where access is limited to door or hallway dimensions. Advantages: - No divider plates or gasket seals. - Maintains full operating pressure rating. - Reduces fabrication complexity and cost. - Simplified field assembly with welded couplings. - Minimizes installation footprint and handling weight.

Top/Bottom Coil Example:

Assembled Example Below:

Option 2: Split by Fin Length (Side-by-Side Coil)

A single coil is divided vertically, creating a header side and return bend side that can be piped together in sequence. How It Works: The Header Side coil is fabricated with four connections—two for the main system supply and return, and two that turn 90° toward the leaving air side. The Return Bend Side coil features its own headers with two connections, also turned 90° toward the leaving air side. Once both coils are positioned, the header side coil feeds the return bend side coil through short interconnecting piping runs, creating a single continuous circuit. Technical Considerations: In certain models, connection orientations or spacing may vary slightly from the original coil design. Installers should anticipate minor repiping or header alignment adjustments to ensure smooth field integration. These are standard adjustments that can be completed without specialized equipment or significant field rework.

For this configuration, additional brackets or center support may be required to stabilize the coils when set in place and to maintain alignment during operation. Applications: Ideal for horizontal units, tight mechanical rooms, or multi-section air handlers. Suitable for retrofits where coil depth or access is restricted. Advantages: - Modular installation for confined spaces. - Eliminates the need for divider plates and pressure restrictions. - Maintains system capacity and flow characteristics. - Simplifies transport and installation logistics.

Header Side Coil Example:

Bend Side Coil Example:

Coil Assembly Example (Side-by-Side Coil Combined)

Installation Advantages

Both split coil options provide significant installation benefits: - Avoid crane rentals: Split coils can be transported through standard service elevators or stairwells. - No wall cutting or structural modifications: Coil sections fit through existing access openings. - Reduced downtime: Assembly and sealing can be completed quickly once sections are in place. - Lower labor and equipment costs: No need for heavy rigging or demolition. - Preserves equipment and building integrity: No compromise to air handler casing or mechanical room walls.

Key Benefits for Contractors

- Simplified field installation in confined or difficult-to-access locations. - Maintains system performance and pressure rating. - Reduces total project cost by eliminating crane, wall, or louver removal expenses. - Shorter lead times and faster turnaround. - Custom-built to match your exact coil design, performance, and circuiting requirements.

Additional Project Requirements

All split coil projects require a site visit before fabrication to ensure accurate measurements and proper design alignment. This step allows us to provide a precise and dependable proposal tailored to your installation conditions.

We can also supply drain pans, either intermediate or main pans, as required by the application to ensure proper condensate management and long-term system reliability.

Comparative Performance Metrics

Coil Tag: As built - Single Piece

Coil Model Number: 4W-08-32.5-10-110.0-52

Hand:Right

Coil Tag: Side-by-Side Split

Coil Model Number: 4W-08-32.5-14-50.5-26

Hand: Right

By adjusting the FPI and circuitry, even though the total surface area decreases on the face of the coil, we are able to increase the overall performance of the unit with minimal effect to fluid and air pressure drops.

Notes:

Certified in accordance with the AHRI Forced-Circulation Air-Cooling and Air-Heating Coils Certification Program which is based

on AHRI Standard 410 within the Range of Standard Rating Conditions listed in Table 1 of the Standard. Certified units may be

found in the AHRI Directory at www.ahridirectory.org

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5 Warning Signs Your Coil Needs Replacement

By Colby Maun • June 29, 2026

In a commercial HVAC unit, coil failure is one of the most frequent and costly problems a system can have. Coil failure in a commercial HVAC unit leads to performance, efficiency, and reliability issues, making it one of the most important aspects in the system. Coils can fail for many different reasons, and understanding when a coil is starting to need replacement can save facility managers tons of extra downtime and stress. Here are 5 warning signs that your commercial HVAC coil needs replacement, so that the next time your coil fails, you can be on top of the problem.

What Makes a Coil Custom?

By Colby Maun • June 22, 2026

What exactly makes a custom coil custom? Most facility managers assume that a custom coil only differs from OEM in sizing. The reality is that dimensions are only a fraction of what makes a custom coil custom. Each job is different, with many different factors going into a custom coil, such as dimensions, tube configuration, fin design, materials, and performance requirements. The most commonly thought of aspect when it comes to custom coils is the dimensions. This includes height, width, and depth of the coil, which allows for custom replacement coils to fit perfectly into the system they are designed for. Doing this without major modifications is crucial when manufacturing a custom replacement coil. The tube configuration of the coil also plays a very important role in customization. The circuitry, number of rows, and tube diameter all impact this aspect and contribute to the efficiency and heat transfer of a custom coil.

How Aging Infrastructure is Challenging Commercial Buildings

By Colby Maun • June 18, 2026

As a building gets older, it becomes much more likely to experience several different types of HVAC failure, which results in decreased efficiency and reliability in the system. Considering the fact that most commercial buildings in the US were built between 1970 and 2000, this aging infrastructure is becoming increasingly problematic in the world of HVAC. To increase difficulty, many organizations postponed renovation and retrofit projects during COVID and during times of economic uncertainty and inflation. Those decisions extended HVAC equipment beyond its initial design life in many cases, and now that it is finally time to renovate, there are significant challenges to doing so in those buildings. With today’s rising equipment costs, aging building stock, high energy costs, sustainability pressures, and limited budgets, many facility managers are burdened with attempting to keep their equipment running smoothly. As HVAC systems age, they experience coil degradation, efficiency losses, corrosion, and increased failures and downtime in general. Coils are usually one of the first parts to deteriorate, as they are exposed to plenty of different weathering aspects in the air, such as salt, moisture, and pollutants, to name a few. When a coil deteriorates, it reduces system capacity as a whole. Efficiency losses in older units are common as well, since with time, the unit has to work harder and harder to remain operating at the same capacity as it was when it was new. Reliability decreases for units due to increased unexpected failures and downtime, along with it becoming harder to source parts for repairs as technology advances and changes.

YCAV Air-Cooled Chiller Conversion Case Study

June 11, 2026

Location: Hotel – Fort Lauderdale, Florida Overview: A 6-year-old York YCAV air-cooled chiller serving a hotel experienced premature condenser coil failure. Out of 10 total coils, 4 had already failed (40%), with the remaining coils showing active corrosion. The unit operates continuously, making reliability critical for guest comfort

HVAC's newest Refrigerants

June 8, 2026

New refrigerant requirements from EPA mandates aimed at reducing greenhouse gas emissions are shaking up the HVAC industry. These requirements are causing a shift from R-410A refrigerant to A2L refrigerants R-454B and R-32. A2L refrigerants are low in toxicity and flammability. The shift is based around a metric called GWP, standing for Global Warming Potential, which measures how much heat a gas traps in the atmosphere compared to carbon dioxide. R-410A has a GWP of around 2,088, which means that 1 pound of R-410A released into the atmosphere has the same warming effect of 2,088 pounds of CO2.

How AI is Reshaping the Future of HVAC

June 5, 2026

Increasing demand for AI, high performance computing, along with hyperscale data center expansion are creating a massive new market for HVAC. The shift is in cooling, as data center cooling is moving beyond incremental airflow optimization, and towards liquid cooling in order to support AI and its specific cooling needs. Because of this, the data center liquid cooling market is projected to expand from 6.6 billion dollars to 38.4 billion dollars by 2033. North America is the current hotspot for this investment as it hosts the largest concentration of AI training clusters globally. Historically, data centers have relied on air-based systems for their cooling, which includes CRAHs, chilled water systems, and precision cooling equipment. Because AI servers are now generating higher heat loads than previously (Modern AI racks can exceed 100 kW per rack compared to the traditional 5-15 kW loads of the past), facilities need heavier duty cooling, sparking the transition to liquid cooling solutions. This transition to liquid cooling is not removing HVAC systems and instead restructures their role within AI facilities. Removing building heat, maintaining environmental conditions, and supporting chilled water distribution systems are all issues that HVAC remains a critical solution to. As a result of this, specialized coils, such as the ones HeatEX produces are growing in demand along with cooling towers, heat exchangers, and other thermal regulation components necessary for dealing with high heat rejection requirements. This trend to support AI with Liquid cooling brings new challenges with infrastructure and compatibility for projects, as operators prioritize power usage effectiveness reduction and carbon footprint optimization. Ensuring coolant compatibility with diverse server architectures, leak prevention, and aligning cooling with rapidly advancing cycles are a few of these challenges. Operators are looking for companies that can specialize towards their plants and customize them to their need.