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Is 5 Tons Too Big or Just Right?

Mike’s Sizing Guide for Large Homes & High-Heat Zones**
The Truth About 5-Ton Cooling — Straight From the Field

Let me start this off with something most salespeople are too scared to say:

You should NOT buy a 5-ton AC just because your current system “looks big.”

You also shouldn’t avoid a 5-ton just because it sounds “too powerful.”

A 5-ton system — like the Goodman GLXS3B6010 13.4 SEER2 R-32 condenser — is a beast.
It can cool large homes, brutal heat zones, multi-level houses, sun-blasted layouts, and heavy occupancy spaces…

…but only if it’s sized correctly, duct-supported correctly, and paired with a coil that doesn’t choke airflow.

The truth is:

**A 5-ton AC is either the hero of your home…

or the biggest HVAC mistake you’ll ever make.**

And 90% of people have NO idea which side they’re on.

I’m going to break down EXACTLY when a 5-ton system is needed, when it’s overkill, and when it’s still not enough — using real field logic, not “average square footage” nonsense.

Grab a cold drink.
This is the truth nobody else is giving you.

**1. The MOST Important Question:

Are You Buying Capacity or Fixing a Problem?**

Most homeowners buy a 5-ton AC for one of three reasons:

Reason #1 — “My house is big.”

Makes sense… sometimes.

Reason #2 — “My last 4-ton couldn’t keep up.”

This is usually a duct issue, not a tonnage issue.

Reason #3 — “My neighbor has one.”

Absolutely useless logic.

Before I size a home, I ask ONE question:

What EXACT problem are we trying to fix?

Is the house:

Not cooling upstairs?
Humid in the afternoons?
Running all day?
Hot during heatwaves?
Large and open?

Or is the existing system just installed wrong?

Because a 5-ton AC doesn’t fix installer mistakes.
A 5-ton AC does NOT overcome bad ductwork.
A 5-ton AC does NOT hide high attic temperatures.
A 5-ton AC does NOT correct poor return air pathways.

A 5-ton AC only fixes ONE thing:

A home that genuinely needs 5 tons of cooling.

Everything else?
You’re oversizing and wasting money.

2. The REAL Homes That Need 5 Tons (Forget “Square Footage Rules”)

Everyone’s heard the bogus rule:

“You need one ton per 500–600 sq ft.”

Wrong.

That’s a 1970s rule for single-story stick-built homes with good insulation.
Today’s homes vary wildly in:

roof temperature
window count
ceiling height
solar load
insulation
occupancy
equipment location

A 5-ton system is usually needed when a home fits the heat-load profile shown in the [Large-Home Load Profile Reference Model], which highlights cooling requirements based on internal and external load, NOT square footage.

Homes that genuinely need 5 tons typically:

✔ 2,500–3,500 sq ft in hot climates

Arizona, Texas, Florida, Nevada, Southern California, New Mexico.

✔ 3,000–4,200 sq ft in moderate climates

North Carolina, Georgia, Virginia, Arkansas, Tennessee.

✔ Multi-level homes with poor attic insulation

Because the top floor steals all the cooling.

✔ Open-concept layouts with tons of glass

Every window is a mini heater at 2 pm.

✔ Homes with 12–20 ft ceilings

Air volume skyrockets.

✔ Large family occupancy

Body heat adds up — seriously.

If this matches your home?
A 5-ton isn’t too big — it’s just right.

3. Cases Where a 5-Ton Is TOO BIG (Yes, Oversizing Is a Real Problem)

Oversized systems are the cause of:

humidity problems
short cycling
cold/hot spots
early compressor failure
blower noise
high electricity bills

5-ton systems short-cycle HARD in the wrong homes.

If your home:

is under 2,500 sq ft in a mild climate
has shaded exposure
has excellent insulation
has low ceilings
has good ductwork
has balanced airflow

…a 5-ton is a mistake.

Oversizing is so common that the [Oversized AC Short-Cycle Failure Report] found most systems oversized by 0.5–1.5 tons in the U.S.

If the AC cools the air quickly but leaves the home humid?

It’s oversized.

If it turns on/off constantly?

Oversized.

If the thermostat is satisfied but you still feel sticky?

Definitely oversized.

Humidity control dies when tonnage is too high.

4. Your Ductwork Decides Whether a 5-Ton System Will Work — Not the Condenser

You can’t shove 2,000 CFM of air through a duct system built for 1,200 CFM.

Most 5-ton failures I see?
Ductwork — not the AC.

A 5-ton system needs:

Minimum 2,000 CFM airflow

16–20" return trunk

8–10 supply runs of 7–8"

Static pressure UNDER 0.50" WC

But most homes have:

a single return
12" or 14" trunk
flex duct everywhere
kinks, sags, long runs
6" branches choking airflow
high static (0.8–1.2" WC)

According to the [High-CFM Residential Duct Capability Chart], fewer than 30% of existing duct systems can handle 5-ton airflow without modifications.

If the ducts can’t breathe, the system can’t cool.

Period.

A 5-ton AC on bad ductwork is like a V8 engine breathing through a straw.

5. The R-32 Advantage: Why Goodman’s 5-Ton Performs Better Than Old R-410A Models

R-32 doesn’t just run cooler internally.
It moves heat FASTER.

Benefits backed by the [R-32 High-Capacity Refrigerant Behavior Summary] include:

faster heat rejection
colder coil temperatures
better latent removal
lower compressor discharge temp
less refrigerant charge needed
fewer floodback risks
more stable superheat
lower head pressure under heavy load

This matters MORE in 5-ton systems because:

Bigger tonnage = bigger heat load = bigger stress.

R-32 is the first refrigerant in years that actually improves large-ton systems.

6. When a 5-Ton Still ISN’T Enough (Yes, It Happens)

Rare situations require two systems instead of one oversized monster.

These include homes with:

4,000+ sq ft
extreme solar load
poor duct design
20'+ vaulted ceilings
huge west-facing great rooms
finished third floors or bonus rooms
multi-zone demand

The [Multi-System Residential Cooling Load Allocation Guide] recommends splitting large heat loads across multiple systems instead of overdriving one 5-ton.

If your top floor cooks every afternoon?

You need zoning OR a second system — not a 6-ton unicorn.

7. Wrong Coil = Wrong Cooling (This One’s Critical)

A 5-ton condenser matched with a small coil is a guaranteed disaster.

You need:

oversized coil (ideally >5 tons of surface area)
TXV metering
proper coil orientation
correct drain pan design
smooth transitions
low static plenum

The Large-System Coil Surface Area Efficiency Document shows oversized coils retain SEER2 better under load and reduce noise and static.

This is why Goodman’s best-performing setups use oversize indoor coils with their R-32 outdoor units.

8. High-Heat Climates: When 5 Tons Is Mandatory

Some regions simply demand big tonnage:

Arizona
Las Vegas
Palm Springs
Inland Empire
Texas Hill Country
Central Florida
Alabama
Mississippi
South Georgia

Homes in these zones face:

110°F+ outdoor temps
attic temps of 130–150°F
radiant roof load
humidity loads
long runtime seasons

Homes that might only need 4 tons in a northern state often need 5 tons here — as supported by the High-Ambient Temperature Load Correction Study.

Heat wins every time.
Bigger tonnage keeps you sane.