Tony Marino’s Guide: Choosing the Right AC for 600–700 Sq Ft Spaces —

Tony Marino here, and today I want to talk about something a little different than usual — sizing your air conditioner when you live in a smaller space. Specifically, what it means when you're looking at cooling around 600 to 700 square feet, whether you're using a portable AC unit or thinking bigger. And yes — I’ll tie it back to a serious central system too, because for some setups, going “full Goodman” might make more sense than just relying on a window or portable unit.

To kick things off, here’s the central system I’ve got my eye on: the Goodman 3‑Ton 14.5 SEER2 R‑32 Bundle. That’s a 3-ton outdoor condenser + matched air handler / coil — a solid, modern system built for performance. But you might be thinking: “Tony, that’s way too big for my 700 sq ft space.” Fair question. Let me walk you through the real trade‑offs.

1. Understanding Your Needs: 600–700 Sq Ft Is a Unique Beast

Let’s start by looking at the smaller square footage — 600 to 700 sq ft.

If you're thinking “ac unit for 700 sq ft”, that’s a very common question.
If you're considering a 600 square feet portable air conditioner, you’re likely looking at a portable or window‑type cooling solution.

What do experts actually say about how much cooling power you need for that kind of space?

According to PickHVAC, you generally need about 20 BTUs per square foot to get a rough estimate. (How to Choose Best HVAC Systems) So for 600 sq ft, that’s roughly:

For 700 sq ft, that number goes up to around 14,000 BTU, depending on your insulation, ceiling height, and how “hot” the room gets. (Forbes)

Another source, AgeCalcX, backs this up with a chart: 550‑700 sq ft rooms often need around 14,000 BTUs, or about 1.16 tons of cooling capacity. (agecalcx.com)

2. The Reality of Portable AC Units (600–700 Sq Ft)

If you're shopping for a portable AC to cool 600 sq ft, or a “700 sq foot portable air conditioner,” here’s the situation from Tony’s playbook:

Pros of Going Portable

Mobility: You can move it around — your living room in summer, the bedroom at night.
No major install costs: You plug it in, vent it through a window, and you're more or less good.
Lower upfront cost: Compared to installing a central AC system, a portable unit is often cheaper — especially for just one room.

But There Are Real Drawbacks

Efficiency: Portable units tend to be less efficient than a properly sized central system.
Noise: Many portable ACs make more noise, especially on full blast.
Drainage: Some portables collect condensate that you have to empty; others need a drain setup.
Venting: They need a hose to vent warm air out; that setup can be clunky or restrict placement.

Given those trade‑offs, here’s what typical sizing guides suggest for portable units: For 600 sq ft, many sources recommend around 10,000 to 12,000 BTUs for portable units — again, depending on insulation, windows, and heat gain. (TheSmallTools)

3. But What About a 3‑Ton Central AC (Yes, Even for a Smaller Space)?

Here’s where I lean in with some real talk. The Goodman 3‑Ton 14.5 SEER2 R-32 Bundle — that beast — has much more capacity than what a 700‑sq-ft portable would need. So why even mention it?

Future Flexibility
If you ever plan to expand, or attach more rooms, or just want the option for more cooling, that 3‑ton system gives you headroom.
Better Efficiency at Scale
Central systems like this Goodman bundle, when properly installed, cool more efficiently for sustained use than many portables. Short-run portables might be convenient, but for long, consistent cooling, a central split system is hard to beat.
Long-Term Value
That Goodman bundle is built to last. A well-installed, well-maintained central system can run 15‑20 years. Portable units? They can work great, but replacement cycles tend to be shorter.
Matched Components
Because the Goodman bundle includes a matched air handler and matched outdoor condenser, you avoid many of the inefficiencies or mismatches that come from mixing parts.

4. How to Choose — Portable vs Central — When Your Space Is ~700 Sq Ft

So, what should someone do if their space is about 700 sq ft and they’re weighing a small portable AC vs a bigger central system? Here's Tony’s decision framework:

A) Ask Key Questions

Am I cooling just one room or multiple connected spaces?
Do I already have ductwork? Or would I need to install it?
How often will I need to run the AC: all summer long, or just a few hot days?
What’s my electricity cost? (A big system running inefficiently costs more than a properly sized one.)
Do I care about long-term reliability, or just a short-term, affordable solution?

B) Run the Numbers

Use a simple rule-of-thumb like 20 BTU per sq ft to estimate your cooling needs.
Factor in real variables: ceiling height, window size, insulation quality. Those change everything.
If you lean toward a central system: get a Manual J load calculation from a pro. That’s the only way to be sure you’re not under- or over-sizing.

C) Make a Comfort + Financial Plan

If you go portable: buy something in the 10,000–14,000 BTU range for 600–700 sq ft, depending on your conditions.
If you go central: consider that Goodman 3‑Ton R-32 bundle if you’ve got or plan to get ductwork, or need more than just one room.

5. Real-World Example: Tony-Style Scenario

Picture this: You live in a 700‑sq-ft loft or small apartment. You’ve been using a portable AC for a couple of summers, but you’re sick of it being loud, draining water, or working overtime on the hottest days.

Option 1 — Upgrade Portable:
You pick up a high‑BTU, efficient “700 sq foot portable AC” (something around 14,000 BTU). You still have vent hoses, but it cools better. It’s a short-term win.

Option 2 — Go Central (Yep, Even for 700):
You talk to an HVAC tech. You run a Manual J. You realize: for not way more money than a high-end portable, you could install a small or midsize ducted system — something like the Goodman bundle gives you power, efficiency, and long-term comfort.

That’s the kind of play I lean toward when I’m thinking like a pro.

6. Common Mistakes People Make

As someone who’s been in the HVAC game a while, here are a few mistakes I see with 600–700 sq ft cooling:

Undersizing or Oversizing Without Calculation
People guess “I’ll just get a 10,000 BTU” or “Why not go 18,000?” without doing a load calculation. That can lead to poor performance or wasted energy.
Choosing Cheap Portables and Replacing Too Often
A cheap portable AC can feel like a bargain — until you’re replacing it in a few years.
Skipping Maintenance
Even portables need to be cleaned and maintained. Filters, hoses, water traps: ignore them at your peril.
Ignoring Ductwork Reality
If you’re going central, bad ductwork ruins everything. Leaks, poor layout, undersized ducts — they all kill efficiency.

7. Why the Goodman 3‑Ton Bundle Still Deserves a Look

Let me circle back to the Goodman 3‑Ton 14.5 SEER2 R‑32 Bundle and why I keep recommending it — even in conversations about relatively small spaces like 700 sq ft:

It’s a full matched central system: outdoors + air handler/coil = designed to work together.
Uses R-32 refrigerant, which is more efficient and better for climate goals than older refrigerants.
The 14.5 SEER2 rating is realistic: you’re not overpaying for ultra-luxury, but you're not cutting corners either.
If installed well, you’re set for the long haul — not just for this season.

8. My Final Take

For a 600–700 sq ft space, a portable AC in the 10,000–14,000 BTU range is often the simplest, cheapest solution — especially if this is your only cooling need.
If you’re thinking long-term, or plan to expand, or just want better comfort with less noise and more reliability, seriously consider going central.
Invest in a load calculation. Don’t guess.
Whatever route you take, make sure installation (portable or central) is done right; poorly installed gear is a problem, full stop.