What Size Goodman System Do You Need? Tony’s Guide to Tonnage, Home Layout & Real Cooling Power

Most people think HVAC sizing is just “square footage divided by something.”
That’s how you end up with hot bedrooms, loud systems, high bills, and equipment that dies years early.

Tony sizes Goodman systems the way they’re meant to be sized — using airflow, insulation, layout, pressure, and real-world performance. Not a napkin formula. Not a guess. Not a “this is what the last guy installed.”

This guide shows you exactly how to choose the right Goodman AC or heat pump tonnage for your home — the same way Tony does it for actual customers every single day.

Let’s build this right.

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1. Why Sizing Matters More Than the Brand You Choose

Goodman makes excellent equipment — efficient, reliable, quiet, and easy to service.
But even the best system will fail if it’s undersized or oversized.

Undersized systems cause:

• long run times

• warm rooms in summer

• poor humidity removal

• high power bills

• premature wear

Oversized systems cause:

• short cycling

• loud airflow

• uneven temperature

• mold issues

• broken compressors

• terrible humidity control

Tony says it all the time:
“The wrong size Goodman will fail faster than a cheap system installed right.”

Sizing is everything.

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2. The Real Tonnage Ranges for Homes (Forget Online Charts)

Those generic online charts that say “2 tons = 1,000 sq ft” are outdated and wrong.
They don’t consider ductwork, climate, insulation, windows, ceiling height, layout, or airflow.

Tony sizes based on real-world conditions, not fantasy charts.

Tony’s Adjusted Tonnage Ranges (Goodman Systems)

These numbers only work when the duct system can deliver the airflow.
Bad ductwork = downsize the tonnage or rebuild the ducts.

(Reference: Residential HVAC Load Calculation Standards)

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3. Climate Zone: The #1 Factor Homeowners Don’t Consider

Two identical homes — one in Ohio, one in Florida — need completely different Goodman systems.

Hot climates (South/Southeast/Desert) require:

• higher tonnage

• higher SEER2

• larger returns

• longer run cycles

• better humidity control

Cold climates require:

• more heating capacity

• heat pump tuning

• correct balance point

• coil sizing for gas furnaces

Mixed climates require:

• balanced tonnage

• correct blower settings

• humidity-focused setup

A 2-ton in Tennessee might be a 2.5-ton in Texas and a 1.5-ton in Michigan.

(Reference: Regional Climate and Temperature Zone Guidelines)

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4. Insulation, Windows & Home Envelope: Hidden Tonnage Killers

Your Goodman system cools the air, yes — but it’s really fighting heat gain from the outside.

These factors change your tonnage requirement dramatically:

• attic insulation levels

• wall insulation

• window age & leakage

• number of exterior walls

• duct leakage

• ventilation and drafts

Tony has cut required tonnage by a full ton after homeowners upgraded windows and attic insulation.

If your home “feels drafty,” say goodbye to your efficiency.

(Reference: Home Insulation and Envelope Performance Manual)

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5. Room Layout & Ceiling Height: Why Open Concepts Demand More Tonnage

If your home has:

• cathedral ceilings

• open living/kitchen areas

• lofts

• split floors

• sunrooms

…you need extra cooling capacity or strategic duct zoning.

Air doesn’t magically fall into the right places.
Tony has sized dozens of 2,000 sq ft open layouts that needed 3.5 tons instead of the expected 2.5.

Goodman systems are strong, but they follow physics.

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6. Ductwork: The Most Important Part No One Talks About

Your home may “require” a 3-ton system —
but if your ducts only support 900 CFM, the biggest Goodman system in the world won’t work properly.

A Goodman air conditioner needs:

• 400 CFM per ton of airflow

• low static pressure

• correct return sizing

• properly sized supply trunks

• well-supported branches

If your static pressure is above 0.6 inches, the system will:

• run loud

• freeze up

• short cycle

• waste energy

• strain the blower motor

Tony refuses to install a system until the duct system is measured — that’s how important this is.

(Reference: Air Distribution and Duct Sizing Reference)

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7. Furnace Blower Strength: The Hidden Sizing Factor With Goodman Systems

Size the outdoor unit incorrectly and you waste money.
Size the blower incorrectly and the whole system suffers.

Goodman air conditioners pair with Goodman furnaces because their blowers are:

• correctly sized

• stronger than most brands

• designed for SEER2 airflow

• quietly balanced

If your furnace blower is:

• old

• PSC motor

• undersized

• restrictive

…you must upgrade it when installing a new Goodman AC.

You can’t push 1,200 CFM through a blower built for 800 — that’s how coils freeze and compressors fail.

(Reference: Equipment Matching and System Compatibility Guidelines)

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8. Sun Exposure, Orientation & Heat Gain

Tony always asks:

• Which side of the home gets the most sun?

• Do you have big south-facing windows?

• Do you have dark roofing material?

These factors can shift tonnage by up to half a ton.

A shaded north-facing home needs less capacity.
A sun-blasted west-facing living room?
That thing needs power.

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9. Heat Pump vs. Straight AC: Tonnage Rules Are Different

Goodman heat pumps size differently than straight AC systems because the compressor handles both heating and cooling.

Heat pump tonnage considerations:

• winter balance point

• defrost performance

• backup heat size

• climate zones

• duct static pressure

In colder areas, Tony may slightly undersize cooling to improve heating efficiency.

In hotter areas, he sizes cooling first, then tunes heat strips.

Goodman systems make both strategies possible.

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10. Tony’s “Field Formula” for Fast Goodman Sizing

This is NOT a replacement for a full load calculation — it’s a field test Tony uses on service calls to sanity-check sizing decisions.

Tony’s 5-Point Sizing Check

1. Square footage

2. Insulation & windows

3. Ductwork CFM capacity

4. Climate zone

5. Home layout & ceiling height

If any ONE of these is “extreme,” the tonnage changes.

If THREE are extreme, rethink the entire design.

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11. When to Choose 1.5 Tons, 2 Tons, 2.5 Tons, 3 Tons, etc.

Here’s the simplified Goodman breakdown Tony uses for customers.

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Choose a 1.5-Ton Goodman System If:

• home is under 1,000 sq ft

• well-insulated

• shaded lot

• modern construction

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Choose a 2-Ton Goodman System If:

• home is 1,000–1,300 sq ft

• average insulation

• standard ceilings

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Choose a 2.5-Ton Goodman System If:

• home is 1,300–1,600 sq ft

• mixed sun exposure

• moderate duct restrictions

• open layout

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Choose a 3-Ton Goodman System If:

• home is 1,600–1,900 sq ft

• moderate to high sun exposure

• older windows or insulation

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Choose a 3.5–5 Ton Goodman System If:

• home is large

• multi-level

• open floor plan

• high ceilings

• heavy sun exposure

• multiple occupancy

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12. What NOT To Do When Choosing a Goodman System

Tony sees homeowners make the same mistakes over and over:

✘ Don’t trust rule-of-thumb charts

✘ Don’t let contractors upsell “just in case”

✘ Don’t reuse old ductwork without testing

✘ Don’t oversize for “faster cooling” — it doesn’t work

✘ Don’t buy a system without checking blower strength

Every one of these leads to comfort issues and wasted money.

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13. Tony’s Final Verdict: The Right Size Goodman = Comfort for 15+ Years

When your Goodman system is sized correctly, you’ll get:

• quiet operation

• low energy bills

• balanced airflow

• consistent temperatures

• strong dehumidification

• long compressor life

Get it wrong, and you’ll feel it every single day.

If Tony had to boil the whole process down to one sentence:

“Size for airflow, size for climate, size for duct capacity — and the correct Goodman system will treat you right for years.”

Let's discuss efficiency ratings and performance with Tony in the next blog.