How to Identify Your Existing PTAC Model Number

Published October 15, 2026 by Philly PTAC, powered by Air Distributors Company, Inc.

The model number on your existing PTAC is the fastest route to the right replacement. It tells a distributor the brand, the series, the cooling capacity, the heat type, and usually the voltage. With it, a quote takes one reply. Without it, the conversation takes several.

This article shows you where to find the model number, what to do when the label is missing or faded, and what to photograph before you send a quote request.

Start with safety

Turn off power to the unit before you remove anything. On a plug-in unit, switch it off at the control panel and unplug it. On a hardwired unit, turn off the breaker. Many 265V units in hotels and high-rise apartments are hardwired. If you are not sure, have your maintenance technician or an electrician do this step.

You need a flashlight and a phone camera. A rag helps, since nameplates collect dust and grease.

Where the nameplate is

Every PTAC carries a rating plate, sometimes called the nameplate or data tag. It is a printed label or a stamped metal plate. Its location depends on the brand and age of the unit, but you find it in one of these places:

On the chassis behind the front cover. Remove the room-side cover. Most covers lift up and pull out, or release with two screws. Look on the side panels of the chassis and around the control box.
Inside the front cover. Some older units carry a second label on the back of the cover itself.
On the chassis base or side, visible only with the chassis partly pulled. Some legacy units place the plate where you see it only after sliding the chassis forward a few inches out of the sleeve.
Behind the control door. A few designs hide the label behind a small hinged door that covers the controls.

Do not confuse the nameplate with other stickers. Many units also carry an energy label, a wiring diagram, and a sticker from the last service company. The nameplate is the one that lists model number, serial number, voltage, amperage, and refrigerant.

What the nameplate tells you

Photograph the whole plate in one clear shot, then take a close-up of the model number line. Here is what each field means for your replacement:

Model number. The most important field. Manufacturers build meaning into it. On many GE Zoneline units, for example, a letter after the series number shows the heat type, E for electric heat or H for heat pump, followed by two digits for the cooling capacity class in thousands of BTU. An AZ45E12 is an AZ45 series electric heat unit in the 12,000 BTU class.
Serial number. Often encodes the build date. Useful for warranty questions and for knowing how old the rest of your units are.
Voltage. Listed as 208/230V or 265V. This must match your circuit. A 265V unit does not run on a 208/230V circuit, and the reverse.
Amperage and heater kW. Tells you the circuit size and how much electric heat the unit was set up to deliver.
Refrigerant type. Older units used R-22. Newer ones use R-410A or newer refrigerants. This matters for repair decisions, not for the replacement order.

When the brand on the cover does not match the plate

This happens more than you expect. Manufacturers sold units under several names. McQuay, for example, built PTACs under the McQuay, Singer, Remington, and Climate Control names before it left the PTAC business in 2014. Some units also wear a replacement front cover from a different brand. Trust the nameplate, not the cover. Send both names if they differ.

When the nameplate is missing or unreadable

Labels fade from heat, peel off, or get painted over. You still have options:

Check another unit. Buildings usually install the same model across many rooms. The unit next door may have a clean label.
Check purchase records. Your maintenance files, a past invoice, or a work order may list the model.
Photograph the unit. Take pictures of the front cover, the controls, the chassis with the cover off, and the outdoor grille. A distributor who handles legacy units often identifies a series from the shape of the chassis and controls.
Measure the sleeve. The wall sleeve dimensions narrow the options quickly. Measure the inside width, height, and depth. The replacement guide shows you how.

A missing label slows the quote down. It does not stop it. Legacy replacements are matched by sleeve size and heat type as much as by model number.

What to photograph for a quote

Before you close the unit back up, take these photos:

The full nameplate, and a close-up of the model and serial numbers
The unit with the front cover removed
The receptacle or the electrical connection
Any pipes connected to the unit, which mean hydronic heat
The outdoor grille, from outside if you have access
The empty sleeve, if the chassis is already out

You do not need to attach photos to the online form. Enter the model number and the details you have. If photos help, a sales rep asks for them in the reply.

Check more than one unit

If you plan to replace several units, check a sample across the building. Corner rooms, suites, and common areas sometimes have larger units. Additions and renovated wings sometimes have a different series. A building that looks uniform from the street often has three or four models inside.

Make a simple list: room number, model number, voltage, and heat type. That list turns a one-unit quote into a building-wide plan. For larger projects, read PTAC replacement planning for hotels and multi-unit buildings.

What happens next

Send the model number with your sleeve size, voltage, heat type, and quantity. The distributor matches it to a current unit:

Older GE Zoneline units on a 42 x 16 sleeve go to a current GE Zoneline model.
Discontinued McQuay, Singer, and Remington units go to a McQuay replacement chassis built to the original sleeve.
Other legacy sizes go to an Applied Comfort chassis built to fit.

The full checklist is in what to send with a PTAC quote request. When you have the model number in hand, request a quote or call 800-866-1210.