What Size Coil Flange Do I Need? (A vs B vs C vs D Explained)
“MRCOOL coil flange sizing chart showing A, B, C, and D cabinet widths and system compatibility.”
If you’re installing or upgrading an MRCOOL Coil and Furnace HVAC system, one small detail can make a big difference:
👉 Choosing the right coil flange
Most people overlook this step—but it directly impacts airflow, efficiency, and how clean your install looks.
What Is a Coil Flange?
A coil flange is the connection piece between your evaporator coil and furnace.
It ensures:
- A tight, airtight seal
- Proper airflow
- Clean system alignment
Without it, you’re left trying to:
- Fabricate sheet metal
- Deal with air leaks
- Risk poor system performance
Understanding Cabinet Sizes (THIS IS WHAT MATTERS)
Your furnace cabinet size determines the flange you need.
A Cabinet (14.5” Wide)
Best for:
- 1.5–2 ton systems
- Smaller homes
- Tight installs
👉 Uses: MCMP1824A-F
B Cabinet (17.5” Wide)
Best for:
- 1.5–3 ton systems
- Most residential installs
- 👉 Uses: MCMP1836B-F
C Cabinet (21” Wide)
Best for:
- 4–5 ton systems
- Larger homes
- Higher airflow demand
👉 Uses: MCMP4860C-F
D Cabinet (24.5” Wide)
Best for:
- 4–5 ton wide cabinet systems
- Maximum airflow setups
- 👉 Uses: MCMP4860D-F
⚠️ Why Choosing the Wrong Size Is a Problem
Using the wrong flange can cause:
- Air leaks
- Reduced efficiency
- Improper airflow
- Costly install mistakes
How to Choose the Right Flange
Before buying, check:
✔ Furnace brand (must be MRCOOL)
✔ Cabinet width
✔ System tonnage
If all 3 match—you’re set.
Pro Tip
Always use manufacturer-specific components when possible.
MRCOOL flanges are designed to:
- Match cabinet dimensions exactly
- Maintain airflow design
- Prevent energy loss
Where to Buy the Right Flange
You can shop all sizes directly from
MRCOOL Direct
👉 View all sizes here:
https://mrcooldirect.com/
FINAL CTA (VERY IMPORTANT)
Don’t guess your install. Get it right the first time.
👉 Shop MRCOOL Coil Flanges Now https://mrcooldirect.com/
👉 Choose Your Exact Cabinet Size
👉 Install Faster & Cleaner
Frequently Asked Questions About MRCOOL Coil Flanges
What Size Coil Flange Do I Need?
What is a coil flange for MRCOOL HVAC?
A coil flange is the connection piece that helps join a cased evaporator coil to a furnace cabinet. It creates a cleaner, more secure, and more airtight transition between the two components.
Why does coil flange size matter?
Coil flange size matters because the flange needs to match the furnace cabinet width correctly. If the size is wrong, you can end up with poor fitment, air leaks, wasted install time, and reduced system performance.
How do I know what size coil flange I need?
You need to check three things:
- Your furnace cabinet width
- Your system tonnage
- Whether the flange is made for your equipment brand
For MRCOOL flanges, the cabinet size is the biggest thing to verify before ordering.
What are the common furnace cabinet sizes?
For the MRCOOL flange lineup, the common cabinet sizes are:
- A Cabinet = 14.5 inches
- B Cabinet = 17.5 inches
- C Cabinet = 21 inches
- D Cabinet = 24.5 inches
Which MRCOOL flange fits an A-size cabinet?
The MRCOOL MCMP1824A-F is designed for A-size cabinets (14.5 inches) and works with 1.5-ton to 2-ton evaporator coils.
Which MRCOOL flange fits a B-size cabinet?
The MRCOOL MCMP1836B-F is made for B-size cabinets (17.5 inches) and works with 1.5-ton to 3-ton evaporator coils.
Which MRCOOL flange fits a C-size cabinet?
The MRCOOL MCMP4860C-F is designed for C-size cabinets (21 inches) and works with 4-ton to 5-ton evaporator coils.
Which MRCOOL flange fits a D-size cabinet?
The MRCOOL MCMP4860D-F is designed for D-size cabinets (24.5 inches) and works with 4-ton to 5-ton evaporator coils.
Are MRCOOL coil flanges universal?
No. MRCOOL coil flanges are designed specifically for MRCOOL furnaces. They are not intended to be universal adapters for other furnace brands.
Can I use a MRCOOL flange with another brand furnace?
No, that is not recommended. These flanges are engineered for MRCOOL furnace compatibility, cabinet alignment, and fitment.
What happens if I use the wrong flange size?
Using the wrong flange size can lead to:
- Poor cabinet alignment
- Air leakage
- Reduced airflow
- Lower efficiency
- A messy-looking installation
- More labor time during install
Does a coil flange improve airflow?
A properly sized coil flange helps maintain correct airflow by creating a better transition between the evaporator coil and furnace. It helps reduce air loss and supports cleaner system performance.
Do I need custom sheet metal work if I use the correct flange?
In most cases, the correct flange helps eliminate the need for custom sheet metal fabrication for that connection point, which can save time and make the install cleaner.
Is the furnace included with the flange?
No. The flange is an installation accessory only. The furnace and cased evaporator coil are separate components and must be purchased separately.
Is the evaporator coil included with the flange?
No. The evaporator coil is not included. The flange is only the adapter used to connect the coil to the furnace properly.
Who should buy a coil flange?
Coil flanges are ideal for:
- HVAC installers
- Contractors
- Homeowners replacing matched system components
- Anyone installing a compatible MRCOOL furnace and cased coil setup
What is the best way to make sure I order the right flange?
Before buying, confirm:
- Your MRCOOL furnace cabinet width
- Your evaporator coil tonnage
- The exact model you need for your install
If those match, you’re in good shape.
Still not sure which flange fits your system?
Shop the full MRCOOL Coil Flanges & Furnace Adapters collection to compare A, B, C, and D cabinet sizes and get the right fit for your install. AT 👉 https://mrcooldirect.com/