If you’ve ever looked at a PTAC unit like the Amana Distinctions 12,000 BTU PTAC with 3.5 kW electric heat, you’ve probably asked:
“What does 3.5 kW even mean?”
“Do I need a special breaker for this?”
“Will this trip my panel if I run the AC and heat at the same time?”
I get these questions a lot, especially from apartment managers, hotel owners, and DIY homeowners trying to stay up to code without hiring an electrician for every little upgrade.
So, let’s break down what a PTAC heat kit actually does, what those kilowatts and amps mean, and how to size everything right for your space.
What Is a Heat Kit in a PTAC Unit?
A heat kit is just an electric heating element, kind of like what you'd find in a toaster or space heater. In a PTAC unit, it's mounted inside the air stream. When you switch the system to heating mode, the element gets red hot, and the fan blows air across it to heat your room.
No gas lines, no refrigerant loops—just clean electric resistance heat.
PTAC heat kits are usually factory-installed or field-installed options and come in several different wattage ratings, like:
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2.5 kW
-
3.5 kW
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5.0 kW
The higher the kilowatt rating, the more heat it puts out—but also the more amps it pulls.
How to Convert kW to BTUs (and Why It Matters)
Want to know how warm a 3.5 kW heat kit will keep your room?
Here’s the math:
1 kW = 3,412 BTUs
So…
3.5 kW = 11,942 BTUs of heat output
That’s plenty for a standard 300–500 sq ft hotel room or studio apartment, assuming average insulation and a moderate winter climate.
But higher elevations, drafty windows, or corner rooms might need a larger kit—or even a backup heat source like baseboard or wall heaters.
👉 This energy conversion chart from Engineering Toolbox makes it easy to translate watts to BTUs.
How Many Amps Does a PTAC Heat Kit Use?
Here’s where most folks get confused—and it’s important because it ties directly into:
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Breaker size
-
Wire gauge
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Room panel limits
For example, a 3.5 kW heater at 230V draws roughly 15.2 amps.
Let’s look at some common pairings:
| Heat Kit Size | Voltage | Amps Drawn | Recommended Breaker |
|---|---|---|---|
| 2.5 kW | 230V | 10.9 A | 15A |
| 3.5 kW | 230V | 15.2 A | 20A |
| 5.0 kW | 230V | 21.7 A | 30A |
You can’t just plug a PTAC into a regular wall outlet. These need dedicated circuits with the right amperage and wiring. Installing a 5.0 kW unit on a 20A circuit? That’s a fire risk.
👉 For accurate amp draw calculations, check out this resistance heat calculator from Southwire.
What Breaker Do You Need for Your PTAC?
Here’s how I explain it to customers:
-
Check the PTAC spec sheet.
Look for the heater wattage, voltage, and amps. The label inside the unit also shows max fuse size. -
Match the breaker size.
Your breaker should be at least 125% of the heater’s continuous load (per NEC 424.3(B)). -
Use the right plug.
PTAC units come with factory-installed power cords designed for 15A, 20A, or 30A outlets. They are NOT interchangeable. -
Don’t guess on wire gauge.
Running a 30A PTAC on 14-gauge wire is dangerous and code-violating. Use a licensed electrician if you're unsure.
PTAC with Heat Pump vs. PTAC with Heat Kit: What's Better?
Good question. Some PTACs also have heat pumps that use the refrigeration cycle in reverse to provide heating.
So which should you choose?
| Feature | Heat Pump PTAC | Electric Heat Kit |
|---|---|---|
| Efficiency | Higher (uses less electricity) | Lower (resistance heating) |
| Operating Temp Range | Limited in cold climates | Works in all temps |
| Initial Cost | Slightly more | Slightly less |
| Breaker Requirements | Lower amps | Higher amps |
In northern climates, I recommend PTACs with both a heat pump and an electric heat backup. That way, you get efficient heating most of the year, but reliable heat when the mercury drops below 35°F.
What to Watch for When Replacing or Upgrading Heat Kits
If you're swapping out a heat kit or replacing a failed unit:
✅ Make sure the new kit matches your unit’s voltage
✅ Check physical compatibility—some PTACs only accept certain sizes
✅ Don’t upsize unless your wiring and breaker can handle the load
✅ Confirm the thermostat supports the heat kit (especially if using remote or wall-mount stats)
Most modern PTACs like those in Amana’s Distinctions line come prewired and labeled, so installation is straightforward—as long as you respect the amps.
Tony’s Final Word
Here’s the bottom line: your PTAC unit’s heat kit isn’t just a simple upgrade—it’s a serious electrical load that needs to be matched to your building’s panel, wire, and breaker.
If you’re replacing an older unit or upgrading from a 2.5 kW to 5.0 kW heat kit, don’t assume you can just plug it in and go. Double-check the specs, and when in doubt, call a licensed electrician.
And remember—bigger isn’t always better. A 3.5 kW heat kit is the sweet spot for most 400–500 sq ft rooms. It keeps you warm without tripping your breaker or spiking your electric bill.
In next article read about: How to Troubleshoot a PTAC Unit That Blows Cold Air in Heat Mode: Tony the Tech’s No-Nonsense Guide
