Short answer: it depends on whether you’re retrofitting existing PTAC sleeves or building/renovating with a clean slate — the right HVAC system for a like-for-like swap is different from the right system for a facade-constrained boutique property or a high-rise tower. Here’s how the top five options actually compare.

1. The Traditional PTAC

Travelers may not know the term PTAC (Packaged Terminal Air Conditioner), but that is exactly what most travelers picture the moment they hear the words “hotel room HVAC.” They are visualizing the ugly box under the window with the plastic grille. It’s cheap to buy and it’s everywhere, which is exactly why it’s still the default in so many properties. It’s also the thing guests complain about most: it’s loud (often in the 55-60 dBA range), it protrudes into the room, and standard filtration (if there is any) does very little for actual air quality. Some other downsides: poor insulation, expensive maintenance, mold risks, and lack of fresh-air circulation.

Best for: Budget-tier properties prioritizing lowest upfront cost over guest experience or long-term operating expense.

2. AIO NextGen PTHP – The Direct PTAC Replacement

Hotels that already have PTAC sleeves, but want to upgrade without huge construction costs or room closures, choose AIO NextGen PTHP. Fitting directly into a standard PTAC wall sleeve, it swaps in without touching the wall opening at all. What changes? Everything: a twin-rotary BLDC inverter compressor instead of a fixed-speed unit, integrated energy recovery ventilation, and a MERV 13 filter.

The sound difference alone is dramatic: legacy PTACs run in the 55-60 dBA range, while NextGen PTHP’s quiet operation sits at 27 dBA (that’s about the difference between a whisper and a running dishwasher). It also sits only about 5.7 inches deep versus the 12-inch protrusion of a standard PTAC, and the built-in ERV recovers up to 81.7% of the energy that would otherwise be lost to ventilation, cutting energy use by up to 73% compared to a standard PTAC’s electric heat.

Best for: Renovations and retrofits where the wall sleeve already exists and a like-for-like swap is the goal. The most common hotel HVAC upgrade scenario.

3. AIO Wall Mounted Pro – Maximum Venting Flexibility

Picture this: a fully self-contained heat pump and ERV system with no outdoor condenser unit at all, mounted high or low on an interior wall. What makes it worth a hotel’s attention specifically is how it vents. AIO Wall Mounted Pro is extraordinarily flexible in how it can externally vent. A host of adapters are available that enable it to be installed in many scenarios, including on glass curtain walls with linear louvers, integrated window and louver assemblies, or even with no construction at all using a windowsill adapter.

This is also the unit behind one of INNOVA’s retrofits at The Gotham Hotel, a 67-room boutique property in Midtown Manhattan. Noisy, underperforming PTAC units were hurting guest scores, so the hotel replaced them with AIO Wall Mounted units. After piloting one unit and seeing zero complaints over a year, they rolled out the rest in phases. The installation was so straightforward that the chief engineer installed half the units himself. The result: maintenance tickets for AC issues dropped to zero, and the hotel qualified for ConEdison energy rebates from the efficiency gains.

Best for: Boutique and design-forward properties, or any building where the exterior facade constraints rule out a standard sleeve or louver.

4. AIO Ceiling Suspended – The HVAC System for When Wall Space Is the Constraint

Imagine a room without usable wall space for a wall-mounted unit (think dorm rooms), budget-tier rooms, or retrofit situations. The AIO Ceiling Suspended model solves that by mounting overhead and out of reach entirely, available with or without an integrated ERV, and vented either directly outside or through ductwork.

Best for: Layouts where floor or wall space is at a premium, or where a ceiling-mounted unit is simply less disruptive to the room’s design.

5. AIO Vertical Stack – For Multi-Story, Multi-Room Efficiency

AIO Vertical Stack is the ideal multi-room solution when a ceiling-mounted unit isn’t feasible or desirable. For high-rise hotels or multifamily-style properties, the Vertical Stack platform threads a single vertical duct run through multiple floors, letting each room maintain fully independent zone control while sharing structural efficiency between floors. A similar multifamily project at the University of Vermont shows the same principle at work. The student housing project used AIO Vertical Stack and Ceiling Ducted units together to solve a cold-climate retrofit challenge in a building originally designed around a different HVAC approach entirely.

Best for: Mid- and high-rise hotel towers where a repeatable, floor-by-floor install pattern matters as much as individual room performance.

Bottom Line: What Separates Each Model?

Cut through the model names, and the real HVAC system decision comes down to four questions:

• Do you already have PTAC sleeves you don’t want to touch? → NextGen PTHP is the direct swap.
• Does your facade rule out a standard sleeve or louver? → Wall Mounted Pro’s adapter range solves that.
• Is wall space the limiting factor, not the exterior? → Ceiling Suspended.
• Are you planning at the building level, not the room level? → Vertical Stack.

Across every one of these, the common thread is worth noting: a decentralized, room-by-room system means one failed unit takes one room offline, not a wing. And a guest who never has to call the front desk about their air conditioner is worth more to a boutique property’s reputation than almost any other single fix.

If you’re planning a renovation or new build and want help matching a configuration to your specific building, talk with our team for a walkthrough of how to optimize what’s best for your property.