Jake’s field-proven method for placing, aligning, and sealing evaporator coils so the furnace blower breathes evenly, cools properly, and never fights against static pressure.
🏗️ 1. Why Jake Obsessively Aligns Coils—Before He Touches a Single Screw
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Most installers treat the evaporator coil as just “the thing that sits on top of the furnace.”
Jake treats it like a precision air-control device.
He says:
“A coil isn’t a box of copper and fins. It’s an airflow machine.
If you land it wrong, the furnace never runs right.”
For the GR9S800803BN, airflow alignment is everything because:
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It uses a high-static blower
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The heat exchanger relies on even air distribution
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Return and supply geometry affect temperature rise
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Misalignment spikes static pressure
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Coil offsets distort airflow
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Poor landing zones lead to hot spots, noise, and premature blower wear
Jake has replaced dozens of failed coils and cracked heat exchangers that were perfectly good units—just misaligned.
80,000 BTU 80% AFUE Upflow/Horizontal Single Stage Goodman Gas Furnace - GR9S800803BN
His Coil Landing Zone Method eliminates:
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Whistling
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Uneven cooling
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Hot or cold rooms
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Blower strain
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Dirty sock smell
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Condensation blow-off
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Coil icing
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Premature heat exchanger fatigue
This method is how Jake delivers “supercharged airflow” installs.
Jake’s 7-Point Coil Landing Zone Strategy
This is the exact workflow Jake teaches every apprentice.
🎯 2. Step 1 — Match Coil Width to Furnace Width (No Overhang, No Pinch)
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The GR9S800803BN is a:
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17.5" wide furnace (nominal cabinet width)
If the coil is:
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Wider → It overhangs → Air hits the coil off-center → Static pressure spikes
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Narrower → Air bypasses the coil sides → Cooling efficiency drops
Jake’s rule:
✔️ The coil must match the furnace within ½ inch total tolerance.
Meaning:
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Max ¼ inch gap on each side
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Zero overhang
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Absolutely no “shelf sticking out” look
Jake says:
“If the coil isn’t sitting flush, the airflow isn’t flowing straight.”
A misaligned coil creates a pressure imbalance across the blower wheel that shortens its life.
📐 3. Step 2 — Center the Coil’s Air Path to the Furnace Blower Inlet
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This is where most installers give up… and where Jake begins.
Jake drops a tape measure:
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From the blower’s centerline
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To the coil’s centerline
Then he adjusts until they match perfectly.
If the coil sits left or right by even an inch, the GR9S800803BN:
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Pulls harder on one side
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Creates a high-velocity side and a dead side
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Makes the furnace sound louder
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Creates temperature-rise imbalance across the heat exchanger
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Reduces cooling efficiency by up to 10%
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Increases total external static
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Damages the blower prematurely
Jake’s rule:
“Air doesn’t turn corners. Give it a straight runway.”
🧊 4. Step 3 — Confirm the Coil’s ‘Landing Zone’ (Bottom Geometry That Controls Airflow)
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Below the coil sits the landing zone—the invisible space where:
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Furnace discharge air compresses
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Air spreads evenly into the coil A-frame
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Velocity stabilizes before hitting copper fins
Jake checks for:
✔️ Even coil bottom contact
No rocking, no gaps, no corner tilts.
✔️ Zero pinch against furnace rails
Pinch → turbulence → noise.
✔️ Coil pan centered over furnace opening
Pan offset = condensate blow-off.
✔️ No internal baffles obstructing landing zone
Especially with all-aluminum A coils.
Jake uses a flashlight and mirror to inspect inside the transition.
He says:
“If the landing zone isn’t flat and centered, the coil never sees balanced air. And the furnace never sees a happy temperature rise.”
🔧 5. Step 4 — Build a Transition That Matches Coil Geometry, NOT Sheet Metal Convenience
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A lazy transition destroys airflow.
Jake builds every transition with:
✔️ A smooth slope
No sharp angles.
✔️ Full contact on all four sides
Air should not hit dead metal.
✔️ No internal obstructions
No screws sticking inside, no shelf lips.
✔️ Proper height
He makes the transition tall enough so the coil can:
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Breathe
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Spread air
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Allow pressure equalization
Jake avoids “too-short” transitions because they make air SLAM into the coil instead of FLOW into it.
His rule:
“Air hates right angles. Give it curves and slopes.”
🌀 6. Step 5 — Seal the Coil Cabinet Airtight (All Four Sides and All Gaps)
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Jake uses:
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Foil tape
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Butyl tape
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High-adhesion mastic
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Zero fiberglass duct tape
He seals:
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Side gaps
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Top gaps
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Rail gaps
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Under-coil seams
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Cabinet corners
If the coil leaks even a little:
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Hot attic or crawlspace air gets sucked in
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Coil load increases
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Condensation increases
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Coil freezes
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Blower static spikes
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Heat exchanger temp rise exceeds limits
Jake’s motto:
“If it leaks air, it leaks money.”
Airtight coil sealing is the backbone of correct airflow.
🧪 7. Step 6 — Jake’s Coil ‘Shadow Test’ (The Fastest Way to See Air Distribution)
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Jake performs his famous shadow test:
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Remove the furnace blower door.
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Fire the blower in cooling speed.
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Shine a flashlight up through the coil.
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Look at the fin shadow on the opposite side.
This reveals:
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Dead zones
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Velocity hotspots
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Uneven air patterns
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Bent coil fins
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Misalignment
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Blockages
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Internal leaks
Jake says:
“The shadow never lies.”
A perfect shadow means a perfectly aligned coil.
🌡️ 8. Step 7 — Confirm Temperature Rise and Coil Pressure Drop
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The GR9S800803BN specifies:
✔️ Temperature rise: 35–65°F
If the coil alignment is wrong, Jake sees:
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High temp rise
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Coil frosting in cooling mode
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Low supply CFM
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Noisy airflow
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Excessive ESP (>0.5" WC)
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Uneven vent temperatures upstairs
Jake checks:
✔️ Coil pressure drop
Too high = misalignment or clogged fins.
✔️ Supply air temp
Too high = coil not receiving enough air.
✔️ Return air temp
Too cold = negative pressure or bypass air.
Jake tunes alignment until:
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Temp rise is stable
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ESP is normal
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Coil delta-T is correct
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Supply airflow is smooth and quiet
Why Coil Alignment Matters So Much for the GR9S800803BN
⚠️ 9. Misaligned Coils Create Blower Death, Noise & Heat Exchanger Damage
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Jake lists the consequences of bad coil landing zones:
❌ High static pressure
The blower works like a vacuum cleaner on carpet.
❌ Hot heat exchanger spots
Cracks form early.
❌ Coil icing
Dead airflow zones → low refrigerant temperature.
❌ Condensate blow-off
Poor alignment directs water into the furnace.
❌ Noise
Whooshing, whistling, or rushing air.
❌ Uneven room temperatures
Back bedrooms freeze while the living room bakes.
Jake says:
“The coil is the traffic cop for your airflow.
If he stands crooked, everyone crashes.”
🧩 10. Jake’s Coil-to-Furnace Compatibility Rules (GR9S800803BN Edition)
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Jake uses these rules every time:
✔️ Coil width must match furnace width (17.5”)
Never mismatch more than ½”.
✔️ Coil cased height must allow proper transition
No “suffocated” coils.
✔️ Coil must be approved for R-410A
If paired with a heat pump or AC.
✔️ Coil tonnage must match or exceed AC capacity
No under-toned coils.
✔️ Coil must be level front-to-back but may tilt 1–2° toward drain
Never tilt sideways.
✔️ TXV sizing must match AC capacity
Not furnace BTUs.
Jake never pairs the GR9S800803BN with:
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Vertical-only coils
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Narrow (14") coils
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Oversized (21") coils without transitions
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Old uncased A coils
He installs matched systems only.
📚 11. External Verified Links (Up to 6)
All safe, engineering-based or government-backed:
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ASHRAE Standards — Air distribution and coil performance
https://www.ashrae.org -
AHRI — Coil matching and equipment compatibility
https://www.ahridirectory.org
🏁 12. Jake’s Final Word on Coil Alignment
Jake says it best:
“The furnace doesn’t decide airflow.
The coil does.
My job is to make the coil and furnace think like one machine.”
With Jake’s Coil Landing Zone strategy:
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Airflow is quiet
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Heat exchanger stays cool
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Coil drains correctly
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Blower lasts longer
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Cooling is stronger
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Efficiency rises
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Homeowners stop complaining about “that one room”
This is how Jake installs every coil—perfectly aligned, perfectly centered, perfectly tuned.
Buy this on Amazon at: https://amzn.to/3L2nAfF
In the next topic we will know more about: Harnesses, Sensors & Safety: Jake’s ‘Touch It Once’ Wiring Method for a Trouble-Free Startup
