Blog

• Discover the warning signs that your coil needs replacing — and why timing matters.
• Learn how custom sizing and coil materials impact performance and longevity.
• See how KCL’s made-to-measure coils are designed for everything from shopping malls to subway stations.

In the world of HVAC and refrigeration, few components are as essential — and often overlooked — as the coil. Whether it’s heating or cooling the air inside a 40-story office tower or maintaining the temperature in a refrigerated case at your local c-store, the coil is doing the heavy lifting.

If you’re managing or maintaining buildings in Ontario — be it a school, transit station, or commercial property — and your system’s coil is on the fritz, you’re in the right place.

This guide covers everything you need to know about Ontario replacement coils — especially those that require precision-matched, made-to-measure solutions. And yes, we’ll show you how KCL helps building operators avoid costly retrofits.

What Are Replacement Coils?

Replacement coils are heat exchangers — either for removing heat (in refrigeration) or transferring it (in HVAC). You’ll find them in air handling units, rooftop systems, chillers, and walk-in freezers.

The two most common types are:

• Evaporator Coils: Found in cooling units and walk-ins, these pull heat from the air.
• Condenser Coils: Located in rooftop and external units, these release heat outdoors.

But not all coils are standard. In large buildings, coils are often custom-engineered to fit a very specific unit and space. Replacing them means you either retrofit the surrounding system — or you match the original specs exactly. KCL makes sure you can do the latter.

Signs You Need a Replacement Coil

Whether you’re managing a busy school campus or a mall HVAC system, catching coil issues early can save thousands in energy and repairs.

Watch for these signs:

• Inconsistent heating or cooling across floors or zones
• Reduced airflow and air quality complaints
• Ice formation or moisture around coil housings
• Unexplained increases in utility costs
• Frequent service calls or system shutdowns

In high-traffic facilities like subway stations and office towers, a failing coil doesn’t just impact comfort — it affects operations, tenant satisfaction, and health standards.

Why Choose Custom Replacement Coils?

Large-scale facilities rarely use off-the-shelf HVAC components. When it’s time to replace a coil, accuracy isn’t optional — it’s critical.

Here’s where KCL shines:

Made-to-Measure, Not Retrofit

Our coils are designed to match exactly what was originally installed. That means no guesswork, no field modifications, and no cutting or welding to make something fit.

Built for Your Building

Whether you’re servicing a Toronto high-rise or a suburban school, we can deliver coils that match the original spec in:

• Size and footprint
• Connection points
• Airflow direction
• Performance characteristics

You get seamless integration — no disruption to your system architecture or ductwork.

Custom Materials and Fin Types

KCL offers various tubing (copper, cupronickel, etc.) and fin configurations, so your replacement is not only identical — it’s optimized for durability and performance.

KCL Systems’ Measuring Services

One of the biggest pain points in coil replacement? Bad measurements.

A misfit coil delays everything — from install to occupancy. That’s why KCL offers on-site professional measuring services, ensuring your coil fits the first time.

We handle:

• Precise field measurements of failed or aged coils
• Drawing validation against original blueprints
• Custom CAD designs ready for fabrication

It’s not just about size — it’s about system integrity. We make sure the replacement coil matches the original thermally and mechanically, every time.

Direct-from-Manufacturer Pricing

Working on a budget? Whether you’re replacing a single chilled water coil or retrofitting multiple units in a public facility, cost matters.

KCL deals directly with coil manufacturers, which means:

• No middleman markup
• Factory-level quality
• Faster lead times

Plus, we’ve spent decades building relationships with some of the best coil fabricators in North America — ensuring you get premium parts at exceptional value.

Serving Ontario’s Largest Facilities

From HVAC coils in train stations to refrigeration coils in c-stores, KCL supports a wide range of commercial and institutional clients:

✔️ Office Towers

Our coils help keep commercial tenants comfortable year-round without disturbing existing ductwork or fan systems.

✔️ Subway & Train Stations

We supply corrosion-resistant coils built for tough environments like transit hubs, where reliability is non-negotiable.

✔️ Schools & Universities

Indoor air quality and energy efficiency are critical. Our coils are designed to improve performance with minimal disruption during installation.

✔️ Shopping Centres

Keep storefronts cool and utility costs down with high-efficiency, custom-fit coils that slip into existing mechanical rooms.

If you’re a facility manager, HVAC technician, or mechanical contractor, we’re the coil partner who shows up with solutions, not surprises.

When it comes to Ontario replacement coils, the difference is in the details — and KCL’s got those locked in.

From measuring to matching, from materials to manufacturer-direct pricing, we help you get the exact coil you need without redesigning your system. Whether it’s for a refrigeration unit in a c-store or a massive HVAC system in a transit terminal, our coils are custom-fit and field-proven.

Need help choosing the right coil? Want to schedule a site visit or get a fast quote?

👉 Contact KCL Systems — and get your system back to peak performance with zero guesswork.

• Evaporator coils absorb heat from indoor air, while condenser coils release that heat outdoors — both are essential to the heat exchange process.
• In HVAC and refrigeration systems, evaporator coils cool the air or refrigerate the interior, while condenser coils expel the system’s collected heat.
• The two types of coils differ in location, material stresses, airflow direction, and exposure — each requiring different design and protection strategies.
• KCL supplies both evaporator and condenser coils for A/C units, chillers, refrigeration systems, and commercial HVAC systems across Ontario.
• With custom fabrication and on-site measurements, KCL ensures each coil is made to match the original spec perfectly — no retrofit required.

When it comes to HVAC and refrigeration systems, coils do the heavy lifting. They move heat from one place to another — keeping buildings cool, food fresh, and air flowing.

But not all coils work the same way. In fact, there are two very different types that each serve a unique role: the evaporator coil and the condenser coil.

Understanding the difference isn’t just useful for technicians — it’s critical for building managers, contractors, and anyone sourcing replacement coils.

What Is an Evaporator Coil?

The evaporator coil is the part of the system that absorbs heat.

In an A/C unit, the evaporator coil is usually located inside the building — often in the air handler or rooftop unit. In refrigeration systems, it’s found inside the cooled space (like a walk-in cooler or merchandiser).

How It Works:

• Refrigerant enters the coil in a cold, low-pressure liquid state.
• As warm air passes over the coil’s fins, the refrigerant absorbs heat and begins to evaporate.
• This process cools the surrounding air before it’s blown into the room or system.

What Is a Condenser Coil?

The condenser coil is the part of the system that releases heat.

In A/C systems, the condenser coil is usually located outside — either in a rooftop unit or on the ground. In refrigeration, it’s often found at the back or top of the system.

How It Works:

• After absorbing heat indoors, the refrigerant is pumped to the condenser as a hot, high-pressure gas.
• As air passes over the coil, the heat is released into the atmosphere.
• The refrigerant cools and condenses back into a liquid to start the cycle again.

Evaporator vs. Condenser: Key Differences

Both types are equally important — and if one fails, the entire system suffers.

Why This Matters When Replacing a Coil

If you’re managing a replacement, knowing whether you need an evaporator or a condenser coil helps you:

• Order the right type with the right material and design
• Avoid system mismatches that reduce performance or cause damage
• Get better longevity by choosing the right coating or configuration

For example:

• An evaporator coil in a transit station may need special antimicrobial or epoxy coatings due to high foot traffic and indoor humidity.
• A condenser coil on a rooftop unit may need UV-resistant, all-copper construction to withstand harsh outdoor weather.

Common Use Cases in Ontario

Evaporator Coils

• Chilled water systems in office buildings
• Cooling coils in walk-in refrigerators and freezer merchandisers
• Air handlers in schools and medical buildings

Condenser Coils

• Rooftop A/C units in shopping centres
• Refrigeration condensing units in c-stores
• Split-system condensers outside apartment buildings

KCL supplies both — custom-built, made-to-measure, and suited to your exact application.

Signs Each Coil Might Need Replacement

Evaporator Coil Red Flags:

• Ice buildup or frost on the coil
• Weak or warm airflow indoors
• Visible leaks or oil stains
• Frequent filter clogging despite replacements

Condenser Coil Red Flags:

• Rising head pressure in the system
• Visible corrosion or bent fins
• Reduced airflow from outdoor fan
• Loud humming or overheating

If your coil is over 10 years old and showing these signs, it’s time to get it looked at — and likely replaced.

How KCL Helps You Get the Right Coil — Fast

Whether it’s an evaporator or condenser, coil replacement can’t be a guessing game. At KCL, we:

• Visit your site and measure the failed coil
• Match the original footprint exactly (no redesign required)
• Recommend material upgrades based on usage and environment
• Work directly with trusted manufacturers to speed up production
• Deliver fast, no-surprise service throughout Ontario

And yes — we know how to tell the difference between coil types, even when the original specs are long gone.

Frequently Asked Questions

Can I use the same coil for both evaporator and condenser?

No — they’re designed for opposite functions, with different pressures, airflow, and orientation needs.

Are condenser coils more durable than evaporators?

Not necessarily. They’re just built differently to withstand weather and outdoor conditions. Evaporators, meanwhile, must resist internal corrosion and humidity.

Can KCL replace both coils in a system?

Absolutely. We can replace one or both coils — measured, matched, and manufactured to your system’s needs.

Whether your issue is heat absorption (evaporator) or heat rejection (condenser), KCL has the coil expertise to keep your system balanced and running efficiently.

👉 Contact KCL to identify your coil type, request a replacement, or schedule a site visit.

• Replacing a commercial HVAC or refrigeration coil without matching the original OEM specs can lead to airflow imbalance, compressor strain, and reduced system life.
• In complex systems like air handlers, chillers, and rooftop units, even small deviations in fin spacing, row count, or casing size can cause major efficiency issues.
• OEM spec matching ensures proper airflow, thermal performance, and compatibility with existing ductwork, controls, and piping.
• KCL eliminates guesswork by providing on-site measurements and custom-made coils that are engineered to match the original — down to the connection and bolt pattern.
• Across Ontario, KCL helps building operators in malls, schools, transit hubs, and office towers avoid costly retrofits by supplying exact-fit coil replacements.

In commercial buildings, HVAC systems aren’t one-size-fits-all. They’re engineered to fit the architecture, airflow requirements, occupancy loads, and mechanical space constraints of each site.

So when a coil fails — and it will eventually — swapping it for a “close enough” replacement can cause more harm than good.

Let’s look at why matching OEM coil specifications is non-negotiable in large-scale buildings — and how KCL ensures your new coil performs just like the original (or better).

What Are OEM Coil Specs?

OEM (Original Equipment Manufacturer) coil specs refer to the exact design specifications used when your system was originally installed.

This includes:

• Dimensions: casing size, finned surface area, row depth
• Airflow orientation: left-to-right, top-to-bottom, etc.
• Tube diameter and pattern
• Fins per inch (FPI)
• Connection size and location
• Thermal capacity and pressure ratings

These specs ensure the coil integrates seamlessly with the existing:

• Air handler or unit casing
• Ductwork and plenums
• Control sequences
• Refrigerant charge and flow rates

What Can Go Wrong If You Don’t Match the Specs?

Plenty. Swapping in a coil that “sort of” fits often leads to serious consequences:

❌ Poor Air Distribution

If the fin area or airflow direction isn’t right, the system may underperform — creating hot/cold zones in the building.

❌ Compressor Damage

Mismatched coils can mess with refrigerant pressures, leading to short cycling, overheating, or even compressor burnout.

❌ Energy Waste

Improper coil sizing leads to longer run times and higher power consumption — all while delivering less comfort.

❌ Vibration and Noise

Even a small casing mismatch can cause vibration, rattling, or resonance issues in the duct system.

❌ Installation Delays

If the coil doesn’t line up with connections or mounting brackets, you’re stuck modifying equipment — adding time, labour, and risk.

Why OEM Matching Is Especially Critical in Commercial Buildings

Larger systems are more sensitive to coil changes. One mismatched component can throw off balance across multiple zones or systems.

For example:

• A slightly deeper coil might increase static pressure, affecting fan performance across the entire floor.
• A different fin spacing might change heat transfer characteristics, requiring a system rebalancing.

In buildings with centralized HVAC, the impact of coil misalignment is multiplied — affecting not just a single office or store, but entire floors, common areas, or tenant suites.

Why “Off-the-Shelf” Coils Don’t Cut It

It’s tempting to save time by grabbing a stock coil that’s “close enough.” But unless it was made for your exact unit, it won’t perform the same — and could lead to costly system issues.

Even if it fits the physical space, it may not:

• Match the original thermal performance
• Support the same refrigerant
• Withstand the building’s environmental conditions

That’s why KCL customizes every coil to match OEM specs or, if those are unavailable, we reverse-engineer based on measurements and system performance.

How KCL Matches OEM Coil Specs — With No Headaches

We don’t guess. We measure, match, and build it right the first time.

✅ On-Site Measurement

If you don’t have OEM documentation, we’ll come to your location and measure the failed coil ourselves — including airflow direction, connection points, and casing layout.

✅ Custom Coil Fabrication

We work with trusted North American manufacturers to create coils that mirror the original in size, spec, and function — without retrofitting or duct modifications.

✅ OEM Spec Retrieval & Engineering Support

We often have access to coil spec databases or can work with equipment manufacturers to retrieve original designs.

✅ Field-Proven Expertise

We’ve matched coils for:

• Chillers in office towers
• Air handlers in schools
• Refrigeration racks in c-stores
• Rooftop units on malls and transit hubs

If it was built, we can rebuild it — exactly.

Real Example: School Board Chiller Coil in Ottawa

A school facility contacted KCL with a leaking evaporator coil in a 20-year-old chiller — with no original documentation.

We:

1. Measured the coil in-place
2. Matched tube and fin configuration based on airflow and refrigerant
3. Delivered a custom-built replacement in 3.5 weeks

The result? Zero retrofitting, one-day installation, and improved thermal performance with new fin coatings.

Frequently Asked Questions

What if I don’t have the OEM specs?

No problem — we’ll measure your existing coil and reverse-engineer a match. Our team can also cross-reference against industry spec databases.

How close is “close enough” for a replacement?

Honestly? Not close enough. In commercial systems, even a small mismatch can have major consequences. Always match the original — or improve upon it with professional engineering input.

Do you supply coils for discontinued equipment brands?

Yes. We specialize in replacement coils for older or legacy systems, including discontinued brands. We build to fit, regardless of the original model.

What industries or building types do you support?

We supply coils for commercial buildings, food stores, transit infrastructure, educational institutions, and more — anywhere precision and uptime matter.

When it comes to commercial HVAC and refrigeration systems, shortcuts cost more. Don’t settle for an almost-fit coil.

Contact KCL today to schedule a measurement or request a quote. We’ll match your OEM coil specs with zero compromises — and no surprises.

• A custom coil isn’t just about unusual sizing — it’s about matching the original coil’s airflow, capacity, material, connection layout, and operating pressures.
• True custom fabrication ensures the new coil drops into place without modifying ductwork, piping, or mounting systems.
• Custom coils are critical in older or specialized systems where off-the-shelf solutions don’t exist or would create inefficiencies.
• KCL handles every aspect of custom coil production — from on-site measurement to CAD drawing coordination and direct-from-manufacturer delivery.
• With deep experience in Ontario’s commercial and institutional sectors, KCL delivers precision-engineered coils for everything from rooftop HVAC units to large-scale refrigeration systems.

You’ve probably heard the term “custom coil” before. But what exactly does that mean? And when is a custom coil actually necessary?

Spoiler alert: it’s more common — and more critical — than you think.

In commercial HVAC and refrigeration systems, coils aren’t always something you can pull off a shelf. Many systems, especially older or purpose-built ones, need coils that fit and perform exactly like the original.

Let’s look under the hood at what makes a coil truly custom — and how KCL ensures your replacement is done right.

What Defines a Custom Coil?

A custom coil is built to match very specific specifications — ones that differ from today’s off-the-shelf models or generic stock options.

This includes:

• Casing size and shape
• Tube layout and diameter
• Fin spacing and materials
• Number of rows and air pass configuration
• Connection location, size, and type
• Orientation for airflow direction (horizontal, vertical, etc.)
• Operating capacity and pressure requirements

In short, if your replacement coil can’t be pulled from a catalog, it’s custom — and needs to be engineered for your system’s exact layout and conditions.

Why Are So Many Coils Custom?

Because HVAC and refrigeration systems vary widely across:

• Building age
• System brand or model
• Environmental needs
• Load requirements
• Design constraints (mechanical room size, airflow, duct placement)

Most coils are originally engineered to fit into a unique air handler, chiller, or rooftop system. When that coil fails, an exact match is often the only way to restore performance without costly retrofits.

That’s where KCL comes in.

What Goes Into Custom Coil Fabrication?

Here’s what happens behind the scenes once you call KCL for a custom coil:

1. Site Assessment & Measurement

We send a rep to measure the failed coil in place, capturing:

• Casing dimensions
• Fin height and length
• Tube diameter and number of rows
• Connection types and distances
• Airflow direction and system orientation

2. Engineering Review

We work with trusted manufacturers to:

• Translate measurements into detailed drawings
• Cross-check thermal capacity and airflow specs
• Adjust for material upgrades (e.g., epoxy-coated fins)

3. CAD Drawings & Sign-Off

You receive a detailed CAD drawing of the proposed coil for approval. Nothing moves forward until everyone is aligned — avoiding mistakes or surprises.

4. Precision Fabrication

The coil is manufactured to spec, using the selected materials and layout. Each bend, weld, and connection is crafted to match your system exactly.

5. Delivery & Support

KCL coordinates direct delivery to your site, so the coil arrives ready to install. We stay in touch with contractors and service teams during the install to ensure success.

Real-World Examples of Custom Coil Needs

🏢 Office Tower Rooftop Unit (Toronto)

A 25-year-old system needed a new condenser coil — but the OEM had been discontinued. We measured the old coil, replicated the casing and connections, and supplied a new one with upgraded fin coating for urban pollution exposure.

🚆 Subway Platform Air Handler (GTA)

High humidity and vibration had caused repeated coil failures. We built a heavy-duty evaporator coil with copper fins and vibration-resistant casing to fit the existing housing perfectly.

🏫 School Chiller System (Ottawa)

The air handler’s coil had an unusual slant-mount configuration. KCL worked with the client’s engineer to reproduce the angle, bracket, and airflow path — no duct changes required.

Why Custom Doesn’t Mean Complicated (With KCL)

The word “custom” can make some building managers nervous — thinking it means delays or higher cost. But with KCL, custom is our standard.

✅ We streamline the process

From measurement to manufacturing, we manage the entire lifecycle. You’re not stuck coordinating between techs, engineers, and vendors.

✅ We reduce errors

Because we measure in the field and review every drawing, our custom coils are right the first time — saving time and install headaches.

✅ We avoid retrofits

Our coils are designed to fit exactly into your system — no welding, patching, or redesign required.

Custom Doesn’t Always Mean “Unique” — Sometimes It Just Means “Not Off-the-Shelf”

Even small deviations — like a different fin spacing or connection thread — are enough to make a stock coil incompatible. That’s why so many coil replacements are, by definition, “custom.”

And that’s exactly what KCL is built to handle.

Frequently Asked Questions

How long does it take to get a custom coil?

Standard lead time is 2–4 weeks, depending on complexity and material availability. Expedited options are often available for urgent projects.

What if I don’t have any specs or drawings?

No problem. We can visit your site, measure the failed coil, and reverse-engineer a match based on performance needs and layout.

Do custom coils cost significantly more?

Not necessarily. While they may cost more than a basic stock coil, KCL’s direct-from-manufacturer pricing keeps costs competitive — and saves you money on labour and retrofit work.

Can you match coils from discontinued equipment brands?

Yes. We regularly replace coils from legacy or discontinued systems — building new ones to match size, capacity, and layout.

If your building needs a coil that doesn’t exist on a shelf, don’t settle for a workaround.

Contact KCL Systems to get a precision-engineered, made-to-measure coil that installs easily and performs exactly as it should.

• Even without original specs, you can identify coil type by looking at airflow direction, tube layout, fin density, and connection orientation.
• Key indicators — such as refrigerant lines, air handler placement, and number of tube rows — help differentiate between evaporator, condenser, and hot/chilled water coils.
• Tube size, casing dimensions, and connection type (threaded, flanged, sweat) provide critical clues for rebuilding or replacing the coil accurately.
• Taking correct measurements and photos allows KCL to reverse-engineer a replacement coil even if documentation is missing.
• KCL offers on-site coil identification and measurement services across Ontario, helping avoid guesswork, downtime, and incorrect orders.

It’s one of the most common scenarios we run into: a coil has failed, and no one has the original drawings, model number, or spec sheet. The unit may be decades old, installed during a renovation, or built into a custom air handler.

Now you’re left wondering — what kind of coil is this, and how do I replace it?

Don’t worry. With a few strategic steps (or a quick call to KCL), you can get the information you need to identify the coil type and get a perfect replacement — no guesswork, no downtime.

Step 1: Determine the Coil’s Function

Start by identifying the purpose of the coil within the system. You can often tell this based on location and refrigerant piping.

🔄 Evaporator Coil

• Typically located inside an air handler or refrigeration unit
• Cold to the touch when operating
• Absorbs heat → refrigerant evaporates inside
• Signs: suction line (larger pipe), cold airflow, condensation pan

🔁 Condenser Coil

• Found in outdoor units (rooftop or pad-mounted)
• Hot during operation
• Releases heat → refrigerant condenses inside
• Signs: hot air discharge, high-pressure lines, external fan

🌡️ Hot or Chilled Water Coil

• Connected to a boiler or chiller
• Contains water or glycol, not refrigerant
• No compressor or expansion valve nearby
• Signs: 2–4 pipe hydronic connections, mechanical room location

Step 2: Look at Airflow Orientation

This tells you how the air moves across the coil and helps define its casing and support configuration.

• Horizontal Airflow: Side-to-side orientation
• Vertical Airflow: Top-to-bottom (common in AHUs and fan coils)
• Slant or “A” Coils: Typically in residential or compact units, set at an angle

Note the direction of airflow relative to the tubes and fins — this will impact replacement coil design.

Step 3: Measure the Coil

Even without drawings, physical measurements give you everything a manufacturer needs to recreate the coil.

Critical Measurements:

• Finned Height & Finned Length
• Casing Height, Length & Depth
• Tube Diameter (3/8″, 1/2″, 5/8″)
• Number of Rows (front to back)
• Fin Spacing (FPI — Fins Per Inch)

Pro tip: Count FPI by measuring 1 inch along the fin line and counting visible ridges.

Bonus Tip:

Take high-resolution photos from multiple angles — including close-ups of:

• Connection points
• Casing flanges
• Tube bends and headers

Step 4: Identify Connection Types and Locations

Improper connection matching is one of the most common failure points in replacement coils.

Record:

• Pipe size (OD) and thread/sweat/flange style
• Connection orientation (left/right/top/bottom)
• Distance from reference points (e.g., coil corner to centerline of inlet)

This helps manufacturers design a drop-in replacement that doesn’t require pipe work.

Step 5: Gather Operational Clues

If the coil is still operating, or if you have access to system design info:

• Refrigerant type or water/glycol mixture
• System pressures or temperatures (if known)
• Load conditions or square footage it serves

All of this supports correct capacity matching — even without an original datasheet.

KCL’s Coil Identification Service

You don’t have to go it alone. If any of the above seems risky, time-consuming, or outside your scope — just call KCL.

We’ll:

• Visit your site
• Measure the coil in place
• Identify type, size, and materials
• Produce a custom-engineered drawing for replacement
• Deliver a drop-in-ready coil built to match

This service is especially helpful for:

• Legacy systems
• Multi-zone air handlers
• Industrial refrigeration units
• Transit, school, or commercial infrastructure

Frequently Asked Questions

What if I’m not sure what type of HVAC coil I have?

Send us photos, dimensions, and connection details. In most cases, we can identify the type from that alone — and confirm it with a site visit if needed.

Do I need original specs to order a coil?

Not at all. We specialize in reverse-engineering coils using physical measurements and system function.

What’s the risk of guessing wrong?

Big. A mismatched coil can damage the system, reduce efficiency, and cause safety issues. That’s why we recommend precise measurements and KCL’s support.

Can you help identify the type of HVAC coil in a custom or older system?

Yes — that’s one of our specialties. We replace coils in buildings that are between 20 and 30+ years old with no design records available.

Can’t identify your coil? No spec sheet? No problem.

Contact KCL — we’ll help you figure it out, measure it right, and get a replacement that fits like it was always there.

• Drop-in coil replacements are custom-built to match the original coil’s size, layout, and performance — making installation faster and avoiding system modifications.
• Retrofit replacements involve adjusting or modifying ductwork, piping, or mounting hardware to fit a non-matching coil — often increasing labour and long-term risk.
• Drop-in coils typically cost more upfront in fabrication, but save significantly on installation, system efficiency, and future maintenance.
• Retrofitting may be appropriate when system specs are no longer available or when major upgrades are planned — but requires careful engineering.
• KCL specializes in drop-in coil replacements that are measured on-site, built to match, and designed to install without cutting, welding, or guessing.

You’re staring down a failed coil. Your system’s limping along. And the big question hits:

Do we retrofit a replacement — or build a drop-in coil that matches the original?

It’s one of the most important decisions building managers, HVAC contractors, and maintenance teams have to make. Get it right, and your system hums along for years. Get it wrong, and you’re chasing leaks, airflow issues, or even structural headaches.

Let’s break down the difference between retrofit and drop-in coil replacements — and why one is usually the safer, smarter, and more cost-effective choice.

What Is a Drop-In Coil Replacement?

A drop-in replacement coil is fabricated to match the original coil exactly — in size, layout, connections, material, and thermal performance.

It’s built to:

• Slide into the existing housing
• Align with current piping and airflow
• Avoid any modification to mounting, ductwork, or supports

At KCL, we create drop-in coils using:

• On-site measurement
• CAD-based fabrication drawings
• OEM spec matching or reverse-engineering
• Custom fabrication by top-tier North American coil manufacturers

What Is a Retrofit Coil Replacement?

A retrofit means using a coil that doesn’t match the original — and modifying the system to make it fit.

That could mean:

• Re-routing refrigerant piping
• Altering duct openings
• Fabricating adapters or mounting brackets
• Making electrical or control adjustments

In some cases, retrofitting is the only option (e.g., a major system redesign), but in most scenarios — it’s a workaround, not a long-term solution.

Comparison: Drop-In vs Retrofit

Why Drop-In Replacements Usually Win

If your goal is restoring original performance quickly and reliably, drop-in replacements are the gold standard.

They:

• Maintain system balance
• Prevent leaks or stress on piping
• Install faster and with fewer surprises
• Support long-term system health

At KCL, drop-in doesn’t mean slow. We measure, spec, and coordinate manufacturing fast — and deliver coils that fit perfectly the first time.

When a Retrofit Might Make Sense

There are situations where retrofitting is valid — and even necessary.

Consider retrofitting when:

• The original coil spec is unavailable, and reverse-engineering isn’t possible
• The entire HVAC system is being upgraded or redesigned
• The application calls for a performance upgrade with new controls or airflow paths
• The building is under major renovation, and layout is changing

In these cases, KCL can collaborate with engineers or contractors to provide a custom-fabricated coil that aligns with the new design.

Real-World Example: Drop-In vs Retrofit in a Toronto Commercial Building

A 15-year-old office tower had a leaking evaporator coil in a rooftop unit. The contractor had a generic coil in stock — but it required new pipe routing and ductwork fabrication.

KCL was called in to assess. We measured the failed coil, matched the original footprint, and delivered a drop-in coil in 3 weeks.

Result:

• 1-day install with no modifications
• Better performance than the stock retrofit would’ve provided
• Total project savings after install: over $2,000

The True Cost of Retrofitting

While retrofit coils may cost less upfront, they often result in:

• Increased install hours
• Higher risk of future leaks or airflow imbalance
• Code compliance issues if modifications are not properly documented

Many contractors and facility managers we work with say the same thing:

“We tried the retrofit route once. Never again.”

How KCL Makes Drop-In Easy

• We measure onsite to ensure precision
• We engineer coils to match your system — not guess or estimate
• We work with top coil fabricators in North America for speed and quality
• We coordinate directly with contractors and maintenance teams to support installation

Our drop-in coils are built to save time, reduce stress, and deliver results.

Frequently Asked Questions

Isn’t a drop-in coil more expensive?

Only slightly in terms of fabrication — but it typically saves much more in installation time, labour, and future reliability.

How fast can I get a custom drop-in coil from KCL?

Typical turnaround is 2–4 weeks, with expedited options available. We can start measuring within days of your request.

What if I’ve already retrofitted before?

No problem — we can measure your current system and create a custom coil that matches your updated layout exactly.

Can KCL help me evaluate whether retrofit or drop-in is better?

Yes — we’ll walk through your system, your timeline, and your budget to recommend the best fit.

If you’re facing a failed coil and weighing your options, don’t guess. Choose the solution that installs faster, lasts longer, and costs less over time.

Contact KCL to schedule a coil assessment or request a drop-in replacement quote today.

• High humidity accelerates coil failure by promoting corrosion, microbial growth, and moisture buildup that leads to leaks and reduced airflow.
• Common high-humidity environments include indoor pools, transit stations, food prep areas, mechanical rooms, and basements.
• Coils in these settings often fail due to fin rot, formicary corrosion, or mold accumulation, especially when made from unprotected aluminum.
• The right solution isn’t just cleaning — it’s using coils with protective coatings, corrosion-resistant materials, and smart airflow design.
• KCL helps Ontario building operators select and supply custom HVAC coils built for humid spaces — with site assessment, upgraded materials, and drop-in-ready design.

If your HVAC system lives in a high-moisture environment, it’s fighting a silent battle every day.

From mold to corrosion to moisture-driven inefficiency, high humidity can destroy coils faster than you think — especially if they’re not built for the challenge.

Whether you manage a transit station, a pool, or a mechanical room in a commercial tower, understanding the risks of high humidity — and how to prevent them — can save you thousands in repairs and replacements.

Let’s break HVAC Coil Failures down.

Why Humidity Is a Coil’s Worst Enemy

Coils are designed to transfer heat. That job becomes harder when they’re constantly exposed to wet, sticky, or saturated air — especially when there’s no coating or corrosion resistance.

Moisture creates the perfect conditions for:

• Rust and pitting
• Fungal and bacterial growth
• Accelerated chemical corrosion
• Clogging and reduced airflow from biofilm buildup

Over time, the result is the same: lower efficiency, higher operating costs, and eventual failure.

Common High-Humidity Environments at Risk

🏊 Indoor Pools and Spas

• Constant airborne moisture and chemical vapors (like chlorine)
• Require epoxy-coated or cupronickel coils to prevent rust

🍳 Commercial Kitchens and Food Prep Areas

• High humidity from steam, dishwashing, and cooking
• Often mixed with airborne oils and chemicals

🚇 Transit Stations and Underground Platforms

• Natural humidity from open-air design
• Increased risk of corrosion due to foot traffic and ventilation challenges

🏢 Mechanical Rooms and Basements

• Poor ventilation and temperature swings
• Often overlooked in maintenance schedules

🧺 Laundromats and Utility Spaces

• High ambient moisture with limited filtration
• Prime conditions for microbial coil fouling

Top 5 HVAC Coil Failure Modes in Humid Environments

1. Fin Corrosion and Rot

Aluminum fins break down over time in wet air, especially if airborne acids or salts are present. The result is loss of structural integrity and heat transfer capacity.

2. Formicary Corrosion

This invisible process creates microscopic pinhole leaks in copper tubing — accelerated by moisture and volatile organic compounds (VOCs) in the air.

3. Mold and Biofilm Buildup

Wet coil surfaces breed biological growth. Left untreated, this leads to airflow restrictions, poor indoor air quality, and even health complaints.

4. Tube Pitting and Leaks

Moisture accelerates metal degradation from the inside out, especially if the system’s water chemistry or refrigerant is off.

5. Premature Freezing

High humidity can lead to frost buildup on evaporator coils — especially when airflow is reduced by clogging or fan issues.

How to Prevent HVAC Coil Failures in Humid Conditions

This isn’t just about wiping down surfaces — it starts with selecting the right coil for the environment.

✅ Use Protective Coatings

Coatings like epoxy or phenolic resin add a layer of protection over the fins and tubes, shielding them from chemical exposure and moisture penetration.

Ideal for:

• Pools and spas
• Coastal buildings
• Kitchens and chemical-heavy zones

✅ Upgrade Materials

• Copper fins and tubing offer better corrosion resistance than aluminum
• Cupronickel coils provide extreme durability for marine, industrial, or poolside use

✅ Space Fins for Airflow

Lower FPI (fins per inch) helps prevent clogging and improves moisture drainage in dirty or damp spaces.

✅ Ensure Proper Drainage

A clogged condensate line can create standing water — which becomes a breeding ground for bacteria and accelerates metal breakdown.

✅ Improve Filtration and Maintenance

• Change filters regularly
• Use UV lights or antimicrobial treatments
• Clean coils with non-corrosive products to avoid stripping protective coatings

Why Custom Coils Matter More in Humid Environments

Stock coils aren’t built for the abuse that humid air can deliver. Worse, they’re rarely designed to match your system exactly.

At KCL, we provide:

• On-site measurement to ensure perfect fit and airflow
• Custom coils built with the right coatings and materials
• Drop-in replacements that install with zero retrofitting

You don’t just need a new coil — you need the right coil for your space and application.

Real Example: Humidity-Proofing a Subway Station Air Handler (GTA)

A major transit hub in the GTA was facing recurring coil failures in underground air handlers. Moisture, dirt, and vibration were causing coils to corrode every 2–3 years.

KCL assessed the environment and replaced the coils with:

• Epoxy-coated copper fins
• Lower FPI design to reduce clogging
• Heavy-duty casings to resist vibration

Result:
Longer lifespan, cleaner airflow, and reduced maintenance cycles.

Frequently Asked Questions

How long should a coil last in a high-humidity environment?

Without protection, 3–7 years is common. With upgraded materials and coatings, 10–15 years is realistic.

Can I just coat my existing coil?

Field coatings exist, but they’re not as effective or durable as factory-applied coatings during manufacturing.

Do you offer antimicrobial coil options?

Yes. We can supply coils with antimicrobial coatings or support UV integration recommendations.

What’s the lead time for a custom humid-environment coil?

Typically 2–4 weeks, depending on materials. We can expedite for critical applications.

Don’t let humidity ruin another coil — or compromise your system’s performance.

Contact KCL to request a coil assessment and get a solution built for the moisture, chemicals, and airflow demands of your building.

• Coil coatings add a vital layer of defense against corrosion, chemical exposure, airborne moisture, and biological buildup in high-risk indoor environments.
• Facilities like commercial kitchens, indoor pools, mechanical rooms, and transit stations expose coils to aggressive air conditions that can cause premature failure.
• Popular coating types include epoxy, phenolic, and polyurethane, each offering protection against different environmental threats.
• Uncoated coils in harsh environments may last half as long as properly coated units — resulting in more downtime, maintenance, and system risk.
• KCL Systems provides custom coils with factory-applied protective coatings, matched to your building’s conditions for long-term durability and lower cost of ownership.

Your coil might be perfectly sized, matched, and installed — but if it’s sitting in a hostile air environment without protection, it’s just a matter of time before it fails.

Humidity. Grease. Chlorine. Cleaning agents. Acidic air. All of these can accelerate corrosion and cause damage to uncoated coils, even if they’re new.

That’s why smart building operators are turning to coil coatings — especially in high-risk indoor environments like kitchens, pools, and transit hubs.

Here’s what you need to know.

Why HVAC Coil Coatings Matter

A coil coating is a protective barrier applied to the coil’s fins and/or tubes — usually during fabrication — to shield against corrosion, chemical exposure, and biological growth.

Think of it like wax on a car. The coating doesn’t change the shape of the coil or how it works — but it makes it much harder for moisture, acids, or contaminants to stick, react, or cause damage.

Without coatings:

• Aluminum fins corrode faster
• Copper tubes develop leaks from formicary corrosion
• Heat transfer drops as fins degrade
• Airflow becomes blocked due to buildup

With the right coating:

• Coils last longer
• Systems maintain performance
• Downtime and service calls drop significantly

Harsh Indoor Environments Where Coatings Are Critical

🍳 Commercial Kitchens

• Constant steam and grease in the air
• Cleaning chemicals and food acids can corrode fins
• Best protection: epoxy-coated or phenolic-coated coils

🏊 Indoor Pools and Spas

• Chlorine vapor is extremely corrosive
• High humidity keeps coils damp
• Best protection: epoxy or polyurethane coatings, cupronickel tubes for extreme durability

🚇 Transit Hubs and Underground Platforms

• Air contains fine particulates, salts, and oils from traffic
• Wide temperature swings increase condensation
• Best protection: epoxy coatings and wider fin spacing

🧴 Cleaning Rooms, Laundromats, Utility Spaces

• VOCs from cleaning agents or laundry chemicals break down metal
• Air is often humid and poorly ventilated
• Best protection: phenolic coating, good drainage design

Common HVAC Coil Coating Types (And When to Use Them)

✅ Epoxy Coating

• Most widely used
• Excellent chemical resistance
• Holds up against humidity, salt, cleaning agents

Best for: Kitchens, transit areas, indoor pools

✅ Phenolic Coating

• Higher UV and heat resistance
• Strong against chemical exposure and abrasion
• Often used in lab or industrial settings

Best for: Laundromats, mechanical rooms, industrial facilities

✅ Polyurethane Coating

• Flexible, durable, good in moist environments
• High resistance to water-based corrosion
• Less chemical resistance than epoxy

Best for: Moisture-heavy spaces with less chemical vapor

✅ ElectroFin / Heresite

• High-end, multi-layered coatings used in severe conditions
• Applied using specialized dipping or spraying techniques

Best for: Marine, industrial chemical, or critical equipment environments

What Happens Without Coatings?

We’ve seen coils in food prep areas fail in as little as 3–5 years due to grease exposure and acid-laced moisture. Once fins start breaking down, performance tanks — and repairs often cost more than replacement.

Typical uncoated coil problems:

• Corroded fins that crumble or fall apart
• Pinhole leaks in copper from chemical exposure
• Airflow blockages due to grime and biological growth
• Early compressor burnout from imbalanced pressures

How KCL Helps You Choose the Right Coating

Every environment is different. That’s why KCL doesn’t just guess — we recommend coatings based on:

• Air quality and humidity
• Cleaning chemical exposure
• Maintenance access and schedule
• Occupant comfort vs operational durability

We provide:

• On-site assessment of coil conditions and risks
• Material recommendations based on decades of application experience
• Factory-applied coatings that are consistent, tested, and warrantied
• Drop-in replacement coils with coatings already in place — no field applications needed

Real Example: Coated Coil Upgrade in a Toronto C-Store Chain

A national c-store chain was replacing evaporator coils every 4–5 years in their high-traffic stores — mostly due to kitchen vapor, defrost cycles, and cleaning sprays.

KCL proposed:

• Epoxy-coated copper fin coils
• Wider fin spacing to reduce clogging
• Drop-in replacements that matched the original footprint

Results:

• Lower refrigerant leaks
• Fewer service calls
• Extended coil life beyond 8 years (and counting)

Frequently Asked Questions

Are coatings applied in the field or during manufacturing?

We strongly recommend factory-applied coatings. They’re more uniform, reliable, and durable than field sprays or touch-ups.

Do coatings reduce performance?

Modern coatings add only a small thermal resistance — usually less than 1–2% — which is far outweighed by the benefits in longevity and reliability.

What’s the cost difference?

Coatings can add 10–20% to the coil cost depending on type — but save much more in downtime and replacement cycles.

Can KCL help coat an existing coil?

We can recommend local coating services or help plan for future replacement with factory-coated coils designed to last.

If your HVAC or refrigeration system operates in a demanding airspace, don’t leave your coil exposed.

Contact KCL to get the right coating for your coil, environment, and building — and prevent the next premature failure before it starts.