What’s Included in a 4-Ton AC + Furnace System (And What Isn’t)?
Mike Unboxes Every Component the Right Way
Let me tell you something every homeowner needs to hear:
Not all HVAC “packages” actually include everything you think they include.
When you buy a 4-ton AC + furnace system, the equipment itself is only HALF the story.
The other half is:
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what’s included,
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what’s NOT included,
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what installers should include,
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what’s considered “optional,”
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and what absolutely MUST be added for a 4-ton system to perform properly.
I’ve seen too many homeowners believe they’re getting a full, complete system — only to find out on installation day that the installer wants to charge extra for:
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line sets
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furnace platforms
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drain lines
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pad replacement
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safety switches
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filter cabinets
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coil transitions
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duct modifications
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electrical upgrades
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thermostat compatibility
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refrigerant disposal
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code-required parts
And none of those are “extras.”
So today, I’m going to give you the full Mike unboxing guide — what’s actually included, what isn’t, and what you MUST have to avoid airflow issues, code failures, noise, and early system breakdown.
Let’s open the box — literally and figuratively.
1. What IS Included in a 4-Ton AC + Furnace System (Standard Equipment)
When you buy a “system,” here’s what you’re really buying.
These are the core components — the stuff that ALWAYS comes with the package.
1. The Outdoor AC Condenser
This is the big metal unit outside.
Every 4-ton condenser will include:
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compressor
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condenser coil
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outdoor fan motor
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top fan assembly
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integrated control board
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refrigerant inside (factory-charged)
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protective cabinet
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access panel
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service valves
What varies:
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staging (single, two, variable)
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noise level
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SEER2 rating
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control electronics
The condenser is the heart of your cooling system, but it’s only one piece of the puzzle.
2. The Indoor Furnace
This is the blower, the heat provider, and the airflow engine.
A 4-ton system requires a furnace that includes:
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blower motor (PSC, ECM, or variable-speed)
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heat exchanger
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gas valve (for natural gas or propane)
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draft inducer motor
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control board
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cabinet
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burners
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safety switches
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integrated filter slot (sometimes)
The critical part for a 4-ton system:
You MUST have a 100k or 120k BTU furnace with enough blower power to move 1,600–1,800 CFM.
A smaller furnace cannot support 4 tons — period.
3. The Evaporator Coil
This sits on top of (or under) the furnace.
It includes:
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coil cabinet
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A-coil or N-coil assembly
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aluminum or copper refrigerant tubing
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TXV metering device
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drain pan built into the cabinet
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insulation
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refrigerant connections
What matters most:
The coil must match:
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refrigerant type
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tonnage
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furnace width
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condenser model
Mismatched coils destroy system performance.
4. Basic Manufacturer Warranty
Most brands include:
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5–10 years parts
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10–20 years heat exchanger
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10-year compressor
But only if the system is registered properly.
5. Basic Installation Hardware (Sometimes Included)
Some kits may include:
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small parts
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screws
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vibration pads
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coil insulation
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refrigerant caps
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drain fitting
This is the bare minimum.
What homeowners don’t realize is how much more is required for a 4-ton system to work correctly.
2. What’s NOT Included — But You Absolutely Need for a 4-Ton System
This is where most homeowners get surprised — and where most installers “upcharge.”
These items should be part of a real installation but often are not included upfront.
1. Line Set (Refrigerant Tubing)
A 4-ton system requires:
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3/8" liquid line
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7/8" (or 3/4") suction line
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thick insulation
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proper routing
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nitrogen-brazed connections
Under [EPA Refrigerant Handling & Ventilation Guidelines], reusing old lines is risky, often illegal, and can contaminate refrigerant.
Yet line sets are almost NEVER included in default equipment packages.
2. Coil-to-Furnace Transition (Sheet Metal Work)
Your coil must fit your furnace cabinet.
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Furnace = 21"
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Coil = 24.5"
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→ You need a transition.
But even if they match, you STILL need a properly sized:
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top plate
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plenum connection
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sealing tape
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sheet metal fittings
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mastic sealing
This custom metalwork is never included in equipment boxes.
3. Furnace Platform or Supports
A 4-ton system is heavy.
Furnaces often require:
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new platform
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reinforced stand
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isolation pads
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leveling shims
Not included.
4. Electrical Upgrades
A 4-ton AC often needs:
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larger breaker
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new disconnect box
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new whip
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thicker gauge wire
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surge protector
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thermostat rewiring
Under [UL A2L Safety & Clearance Requirements], electrical must meet modern code.
Equipment packages do NOT include electrical gear.
5. Thermostat (Unless Specified)
The default system does NOT include a thermostat unless the package explicitly states it.
And if you're installing:
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two-stage systems → you need a two-stage thermostat
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variable-speed systems → you need a communicating thermostat
Thermostat mismatches ruin performance.
6. New Pad or Mounting System for the Condenser
Your old pad is usually:
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too small
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tilted
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cracked
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made for a smaller unit
A 4-ton condenser requires:
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30–36 inch composite pad
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or wall brackets
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or a riser system
Not included.
7. Drain Line + Safety Devices
A 4-ton coil generates A LOT of water.
You MUST have:
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a primary drain
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a secondary drain
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float switch
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proper slope
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PVC or CPVC piping
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drain trap
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emergency pan (for attics)
None of this comes in the box.
8. Return Air Modifications
A 4-ton system requires 3–4 square feet of return grille space.
Most homes don’t have it.
You will need:
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larger return grille
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wider return drop
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new filter cabinet
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new return box
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new duct transitions
None of this is included in a standard system purchase.
9. Supply Duct Modifications
Most homes don’t have enough supply capacity for 4 tons.
Expect to need:
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trunk upsizing
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branch upsizing
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more supply vents
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flex duct replacement
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balancing dampers
Under [ASHRAE Installation & Airflow Standards], a 4-ton system requires 1,600–1,800 CFM.
Your ducts must match — and no equipment manufacturer includes ductwork.
10. Refrigerant, Vacuum, Brazing & Commissioning
Every 4-ton system must be:
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brazed with nitrogen
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evacuated to 500 microns
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charged to spec
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leak-tested
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airflow tested
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static pressure tested
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temperature split checked
None of this is “included equipment.”
This is labor — separate from parts.
3. What’s ONLY Included in Premium Packages (But Not Standard)
Some installers include “premium” items at a higher tier.
These include:
✔ Media filter cabinet
✔ UV light
✔ IAQ packages
✔ Wi-Fi thermostat
✔ Line-set concealment
✔ Compressor sound blanket
✔ Surge protector
✔ Whole-home humidifier
✔ Whole-home dehumidifier
✔ Hard-start kit
✔ Condensate pump
These are comfort and performance upgrades — but NOT essential.
4. What Should NEVER Be Considered “Extra” (Mike’s Rules)
These items are often marked as “add-ons,” but for a 4-ton install, they are mandatory:
✔ Correct line-set size
✔ Safety float switch
✔ Proper drain trap
✔ Proper coil transition
✔ Proper plenum sealing
✔ Correct electrical
✔ Proper refrigerant charge
✔ Blower tuning
✔ Static pressure testing
If your installer tries to upcharge you for ANY of the above?
Run.
5. The Items Most Homeowners Forget to Ask About
Here are the surprise items homeowners ALWAYS overlook:
❗ Condenser surge protection
❗ Furnace surge protection
❗ Full code-level disconnect
❗ Overflow protection for attic systems
❗ Cabinet insulation thickness
❗ Line-set insulation thickness
❗ New smoke detectors (for gas furnace installs)
❗ Gas shutoff valve upgrades
❗ Vent pipe upgrades
These pop up on installation day more often than not.
DOE HVAC Efficiency Requirements
6. What SHOULD Be Included in a Professional 4-Ton Installation
Here’s Mike’s list of what a legitimate installation includes:
✔ Full equipment (condenser, coil, furnace)
✔ Line-set replacement
✔ New pad or risers
✔ Electrical upgrades
✔ Thermostat (matched to staging)
✔ Return air upsizing
✔ Supply duct improvements
✔ Proper coil transition
✔ Condensate drain + safety switches
✔ Refrigerant evacuation + charge
✔ Blower calibration
✔ Static pressure verification
✔ Airflow balancing
✔ Duct sealing
✔ Full startup commissioning
✔ Warranty registration
This is what turns a system into a complete system.
Without these steps, you’ll lose:
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efficiency
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comfort
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longevity
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warranty coverage
7. Mike’s Final Verdict: What’s Really Included (And What Isn’t)?
Here’s the straight truth:
✔ The equipment package includes ONLY the equipment.
✔ Everything else is installation and materials — NOT included.
✔ Most “extras” are actually mandatory in 4-ton systems.
✔ Cheap bids leave out essential installation components.
✔ 4-ton systems require bigger ducts, returns, electrics, and transitions.
✔ A complete system is more than a condenser and furnace — it’s an entire airflow ecosystem.
When done right, a 4-ton AC + furnace combo is a powerhouse that cools large homes efficiently, quietly, and reliably for 15–20 years.
When done wrong?
You get noise, humidity, hot rooms, high bills, and early failure.
Always ask what’s included.
Always ask what’s not.
And always choose the installer who explains BOTH.
That’s the Mike way.
