Adaptive-reuse renovations challenge climate controls

Converting a unique building into a hotel seems like a great idea, right up until you get under the hood and see what you’re dealing with.

These projects are in vogue right now as developers strive to satisfy guests' desire for out-of-the-ordinary hotels, but Jerad Adams, director of commercial product management at Friedrich Air Conditioning, said they are also headaches for heating, ventilation and air conditioning installations.

“In adaptive reuse, the original HVAC system has to be redesigned completely to satisfy both conditioning and to meet updated building codes,” Adams said. “The biggest issue then becomes what HVAC technologies should we utilize to meet the new tenant's comfort conditions, meet all building codes and regulations and minimize the space necessary to install the HVAC system.”

For example, Victor Perez, senior director of sales for the Eastern region at Samsung HVAC, said ceiling heights in older buildings surprise many developers. Modern buildings average 8-foot, 4-inch ceilings, but many older buildings have ceilings just 7-feet, 6-inches high. This is often not high enough to comfortably run an HVAC duct through a room, and is particularly egregious aesthetically.

“One big surprise we found in the Midwest U.S. was the large number of wood roofs we began to uncover,” Perez said. “That then becomes a structural problem. We’re used to putting satellite dishes and air-conditioning systems on roofs, but a wood roof changes that.”

One answer, Perez said, would be to mount an HVAC system on an exterior wall structure, such as in an alleyway. However, in some cases it’s simply impossible to pull off, and a packaged terminal air conditioner installation is recommended instead.

The decision to install PTAC versus HVAC units in a hotel often comes down to cost, with PTACs often being relegated to budget properties due to their lower installation expenses up front. After all, Perez said most PTAC installations only require a 42-by-16-inch hole in the wall and a metal sleeve cover. Of course, it’s not that simple in an adaptive-reuse property.

“Hoteliers in an older building need to ask themselves if they can reliably get enough power to reach each PTAC if one is placed in every guestroom,” Perez said. “That’s a limiting factor, and electricity then becomes a large expense for each room.”

PTACs also traditionally are a source of negative guest feedback due to noise issues. For this reason, their implementation must be carefully considered when working on a new property because their installation requires permanent modifications to a building’s exterior and may not be preferable in the long term.

Another option for hotels comes in the form of variable refrigerant flow systems, which Douglas Mackemer, national director—parts supplies & specialized equipment at Carrier Enterprise, said is a ductless alternative that requires 2 inches to 3 inches of space to run refrigerant lines. These can be expensive, however, and also require some real estate on your hotel’s roof.

“VRF seems to be a lot more popular in renovations now since you don’t have to cut holes in the exterior of a building to use it,” Mackemer said. “Location—and cost—is a factor, though.”

Joining the Network

Energy-management systems become more cost-effective each year, and many of them are able to interface with older machines. This begs the question, then: How old can a PTAC or HVAC system be and still reliably network with energy management?

Mackemer said he has seen a number of 20-year-old Carrier PTAC units still in operation throughout the marketplace, which shouldn’t come as a surprise. With proper maintenance, just about any PTAC will hang tough and do its job. But will a 20-year-old PTAC work with energy controls? Mackemer said it isn’t likely.

“They don’t have the digital interface to accept energy management,” he said. “Most everything in the past seven to 10 years has the adaptability to accept energy-management systems, but I still see a lot of properties that don’t utilize anything.”

Because energy-management systems are so effective at cutting costs in hotels, this is clearly a missed opportunity. Scott Stayton, director of marketing and product management for the Climate Control Group, said PTAC units are typically more limited in their ability to adopt predictive technology, but depending on the building-management system or what the hotel owner is trying to accomplish through energy management, it’s possible to install a system that offers at least some level of savings.

“These days everything is moving in the direction of improving the guest experience,” Stayton said. “The Internet of Things will come to this space, and people are trying to find a place for it. Systems that can detect if a guest is in or outside of a certain range of a guestroom are not far off, even if they are just tracking whether or not a guest checked into a property. From there, the system could monitor the room’s temperature and ensure you aren’t wasting energy on unoccupied space.”

It’s a sign of the times that concepts such as these don’t feel far-fetched. Mackemer said that many hotel companies are beginning to mandate that thermostats be placed on walls away from keypad controls, something he considers to be the first in a series of steps that will move the industry toward a larger adoption of energy-management systems.

“The sheer cost of these systems has dropped significantly already,” Mackemer said. “We have seen a lot more interest recently, and the real advantages behind these systems is that so often they operate seamlessly in the background, beyond guest considerations.”