When homeowners ask me what size air conditioner they need, they’re usually talking about a full home system—something like a 3-ton unit for 1,500 square feet or a 4-ton unit for 2,500 square feet. But lately, more and more people have been reaching out about cooling smaller living areas, especially as home layouts evolve and flexible spaces become a bigger part of how people live.
I’ve received questions like:
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“What’s the best AC unit for 700 sq ft?”
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“Can a 600 square feet portable air conditioner actually cool a space comfortably?”
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“What size portable AC do I need for 700 sq feet?”
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“Are portable AC units for 600 sq ft reliable?”
Whether you’re cooling a studio apartment, a large bedroom, an office, an in-law suite, a basement lounge, or an oversized bonus room, sizing matters just as much here as it does for whole-home HVAC systems.
And today, we’re going deep into the world of small-space cooling—from portable units to built-in solutions to when it actually makes more sense to consider a whole-home system like the Goodman 3-Ton 14.5 SEER2 R-32 Bundle, which you can explore here on our product page:
👉 https://thefurnaceoutlet.com/products/goodman-3-ton-14-5-seer2-r32-bundle
Even if you don’t think you need a full HVAC upgrade, trust me—by the end of this guide, you’ll know exactly what cooling option works best for your 600–700 sq ft space and when to skip portable units altogether.
Let’s get started.
Understanding Cooling Needs for 600–700 Sq Ft Spaces
Before we talk about portable air conditioners, let’s get clear on terminology.
BTUs: The Starting Point of AC Sizing
Air conditioners are sized in BTUs—British Thermal Units. The higher the BTU rating, the more cooling power.
For a quick baseline:
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600 sq ft typically requires around 12,000 BTUs (1 ton).
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700 sq ft usually needs 13,000–14,000 BTUs.
But—and this is important—these numbers don’t account for:
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Heat load
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Ceiling height
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Insulation
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Sun exposure
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Window size
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Humidity
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Appliances
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Whether people sleep or work in the space
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Whether the room is above a garage or basement
This is why a 600 square feet portable air conditioner or a 700 sq foot portable air conditioner doesn’t always perform the way people expect.
Portable Air Conditioners: Good, But Not Always Great
Portable ACs are incredibly popular because:
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They’re inexpensive
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They’re widely available
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They don’t require installation
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They work in apartments
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No permanent changes to the home are needed
But here’s the truth that many manufacturers gloss over:
Portable AC units lose a LOT of cooling power through exhaust hoses.
On average, portable air conditioners operate at 60–70% of their stated BTU rating once you factor in heat loss.
This means:
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A “12,000 BTU portable AC” may cool like a 7,500–8,000 BTU unit
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A “14,000 BTU portable AC” may cool like a 9,000 BTU unit
So when someone comes to me and says:
“I bought a portable AC unit for 600 sq ft and it still feels warm.”
I’m not surprised at all.
It’s not your fault.
And it’s not the brand’s fault either.
It’s the physics of portable cooling.
How to Choose the Right AC Unit for 700 Sq Ft
Let’s break this down room by room.
If the room is well insulated:
Choose a 14,000 BTU portable AC for 600–700 sq ft.
If the room gets heavy sunlight or has many windows:
Move up to a dual-hose portable AC, which cools more efficiently.
If the room is over a garage, basement, or attic:
Choose a mini-split or through-the-wall unit instead of a portable AC.
If the room is part of a larger home cooling problem:
A whole home solution—like the Goodman 3-Ton R-32 Bundle—may be the better investment.
Why Single-Hose Portable ACs Struggle to Cool 700 Sq Ft
Single-hose units operate by taking indoor air, cooling it, and venting hot air outside.
The problem?
When hot air is vented out, it creates negative pressure, pulling warm air back into the room through:
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Walls
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Doors
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Cracks
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Electrical outlets
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Floors
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Windows
This constant heat intrusion reduces efficiency enormously.
For homeowners trying to cool 700 sq ft or more, this is where frustration starts.
Dual-Hose Portable ACs: A Better Option for Larger Single Rooms
Dual-hose portable units use:
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One hose for intake
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One for exhaust
This system avoids the “vacuum effect” and maintains pressure balance in the room.
For many 600–700 sq ft rooms, this can be the difference between:
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“Barely cool enough…”
and -
“Ahhh… finally comfortable.”
If you want to explore the concept of heat load further, here’s a great reference:
https://www.energy.gov
This gives you a picture of how insulation, sun exposure, and heat gain affect BTU needs.
When a Portable AC Unit for 600–700 Sq Ft Makes Sense
Portable ACs are ideal when:
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You are in an apartment and cannot install anything permanent
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You only need temporary cooling
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You want to cool one room at a time
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You need a fast, low-cost solution
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You’re renting and cannot modify the space
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You’re cooling a guest room temporarily
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You’re supplementing an older HVAC system
If this describes your situation, a portable AC unit for 600 sq ft or a 700 sq ft portable air conditioner is totally reasonable.
But if you’re looking for long-term comfort, more durable performance, or a cooling solution that adds value to your home, portable is rarely the best choice.
Mini-Split vs Portable AC for 600–700 Sq Ft
Many of my clients eventually ask:
“Should I buy another portable AC or just get a mini-split?”
Here’s how they compare.
Portable ACs
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Lower upfront cost
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Easy to move
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No professional installation needed
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No structural changes
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BUT lower efficiency
Mini-Split Systems
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Higher efficiency
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Whisper-quiet
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No ductwork needed
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Long lifespan
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Great for 600–700 sq ft rooms
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Higher upfront cost
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Permanent installation
If your cooling needs are more than temporary, a mini-split almost always wins.
For energy efficiency research, here’s another useful reference:
https://www.epa.gov
What If You Need to Cool More Than One Area?
This is where the conversation naturally shifts from “portable AC” to “whole home cooling.”
A portable air conditioner—even a 700 sq ft portable unit—is still a single-room solution.
But if:
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Your entire home is struggling to stay cool
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The main AC is too small
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Multiple rooms feel hot
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Your system short cycles
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You want long-term efficiency
Then it's time to look at a whole-house upgrade.
And that brings us to the star of this discussion…
Why Many Homeowners Choose the Goodman 3-Ton 14.5 SEER2 R-32 Bundle Instead
Even if you’re only cooling 600–700 sq ft right now, many homeowners end up needing a complete HVAC refresh because:
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Their old system is oversized or undersized
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Efficiency has dropped
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Utility bills are rising
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Their refrigerant is outdated
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They want more comfort throughout the home
The Goodman 3-Ton 14.5 SEER2 R-32 bundle is a future-ready, efficient, durable system that offers:
✔ Better airflow
✔ Lower humidity
✔ Lower energy bills
✔ Quieter operation
✔ Significant home value improvement
✔ R-32 refrigerant (modern, cleaner, safer, regulated)
And remember, you can explore the full details here on the product page:
👉 https://thefurnaceoutlet.com/products/goodman-3-ton-14-5-seer2-r32-bundle
The Truth About Trying to Cool 700 Sq Ft With a Portable AC
Yes—it’s possible.
But is it ideal?
For short-term use: Sure.
For long-term comfort: Not really.
Portable AC units for 600 sq ft or 700 sq ft will:
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Work harder
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Be noisier
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Cost more to operate
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Wear out faster
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Struggle on very hot days
Most are simply not designed for consistent, whole-season use.
If you want to evaluate air quality and indoor climate considerations, here’s another helpful resource:
https://www.ashrae.org
What About Heating?
Many homeowners forget this part.
A portable AC cools—but does NOT heat (unless it’s a heat-pump model, which is rare and inefficient).
A mini-split or full HVAC system gives you:
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Cooling
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Heating
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Air filtration
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Humidity control
That’s why portable ACs are temporary solutions, not home comfort systems.
How Much Cooling You Actually Need for 700 Sq Ft
Here’s my go-to recommendation based on decades of experience:
Good insulation, low sun exposure:
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12,000–14,000 BTU portable AC
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Or a 1-ton mini-split
Poor insulation, high sun exposure:
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14,000–15,000 BTU portable AC
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Or a 1.5-ton mini-split
Multi-purpose rooms (gym, office, gaming room):
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1.5-ton mini-split minimum
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Portable often can’t keep up
Part of a larger cooling issue:
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Consider upgrading your main system
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The Goodman 3-Ton R-32 Bundle is often the ideal solution
For deeper technical energy management guidance, here’s another reference:
https://www.energystar.gov
Final Thoughts: Which AC Is Right for Your 600–700 Sq Ft Space?
To summarize:
✔ Portable AC
Best for renters, temporary use, or low-cost solutions.
✔ Mini-Split
Best for long-term, quiet, efficient comfort in 600–700 sq ft rooms.
✔ Whole Home AC
Best when your home’s existing system struggles and you want true comfort.
If you're ready to explore a long-term, whole-home solution that improves cooling in every room—not just one—take a look at the Goodman 3-Ton 14.5 SEER2 R-32 bundle here:
👉 https://thefurnaceoutlet.com/products/goodman-3-ton-14-5-seer2-r32-bundle
