When guests stay at a hotel, they expect to be comfortable. Whatever they may put up with at home or at work, they don’t expect to have those same issues at a hotel.

Matt Ganser, who has worked on both office buildings and hotels as EVP of technology and engineering at the energy-savings-as-a-service company Carbon Lighthouse, said the guest experience at hotels consequently plays a much larger part in deciding how to handle maintenance of the heating, ventilation and air conditioning systems.

“Guests in a hotel, certainly hoteliers themselves, they have a very high threshold for comfort that sometimes drives the decision-making beyond simply energy efficiency,” said Ganser.

Deciding Whether to Maintain or Upgrade

To guarantee that level of guest comfort, hoteliers must ensure their property’s HVAC is well taken care of and know when it is time to buy new equipment.

In general, Dennis Cobb, senior director of business development at Mitsubishi Electric Trane HVAC US, said 10 years is a good benchmark for hotels to evaluate if it’s time for an upgrade. For machines using variable refrigerant flow—these systems require less maintenance and experience less wear and tear than fixed-capacity traditional systems, according to Cobb—the system's lifespan can stretch to 15 to 20 years, he said.

Ganser said there are a lot of warning signs when equipment reaches the end of its useful life, such as maintenance costs going up and unplanned and routine downtime. “Those are oftentimes really good leading indicators that it’s time to go,” said Ganser.

However, Ganser’s colleague Charlotte Helvestine, VP of engineering at Carbon Lighthouse, noted there are sometimes situations where replacement is not necessary. At one of the hotels Carbon Lighthouse recently partnered with, The Westin Maui Resort & Spa, Ka'anapali in Lahaina, Hawaii, Helvestine said the company noticed one of the property’s two chillers consumed much more energy than the other. Though this raised the specter of needing to buy a new chiller, she said further inspection revealed a failed controller on one of the pumps to be the root cause of the issue.

“That kind of example is not always the case; sometimes it is the right call to replace the equipment but I think looking at energy efficiency first is a way to evaluate whether there are lower-cost options to get to the same client goals of better energy efficiency and better operations,” said Helvestine.

Similar to Carbon Lighthouse, the Energy Intelligence Center’s OptikW platform focuses on optimizing properties’ existing HVAC system to improve energy efficiency, often extending the system's life. Charlie Szoradi, CEO at the Energy Intelligence Center, compared OptikW to an orchestra conductor. Because various elements of a hotel’s HVAC system, from the chiller to the cooling tower on the roof, may not come from the same manufacturer, they do not necessarily communicate with each other, which is where OptikW comes in, Szoradi explained.

“We're not replacing equipment or existing tools, we’re enhancing those tools,” Szoradi said.

What Can Cause HVAC Efficiency to Wear Down

In Ganser’s experience, any of a large number of things can degrade energy efficiency, including room improvements changing how controls are run, the addition of a new wing to the facility, the facility engineer leaving the property or a specific relay not working any longer.

“Energy efficiency doesn’t go away in a vacuum,” Ganser said. “It’s usually lots of little things and it’s rare that they’re so egregious or large that you could actually pick it up in a monthly bill or in some sort of warning in a building-management system. It’s a combination of events that will lead to those losses.”

Cobb said that if a hotel notices HVAC performance is waning, it likely is because it has overlooked basic upkeep, i.e. cleaning coils, washing the reusable filters, checking the electrical connections and inspecting the refrigerant lines.

“Because an issue with an HVAC unit can be less obvious than say a stain on the carpet of the hotel lobby, it can be easy to overlook,” he said. “We encourage hotels to remain vigilant and create a regular schedule for HVAC checks, cleaning and maintenance to prevent a problem from developing in the first place.”

Szoradi suggested spreading the energy load when possible. In his work, he said he's seen hotels often will use their prime chiller plant up to its capacity while keeping backup chillers unused. “We find that based on the spec of the chiller that it might run at optimal efficiency at 65 percent,” he said. Szoradi gave the example of a hotel with a 500-ton chiller and two back-up 200-ton chillers and a demand for 500 tons of cooling. Instead of putting the full demand on the primary chiller, he said OptikW will split it between the different plants, perhaps running the primary one at 300 and the others at 100.

“By sharing that load, it’s like running a car at lower [revolutions per minute],” Szoradi said. “You reduce the strain on the existing equipment and you increase the longevity, which reduces maintenance labor costs and time.”

PTAC Maintenance

Barry Bookout, director of sales for Friedrich Air Conditioning Co.’s lodging sales division, and TJ Wheeler, Friedrich’s VP of product management, offered some maintenance tips for PTAC units.

Bookout identified two categories of maintenance: monthly and seasonal. He said hotels should remove, wash, dry and replace the machine’s two washable filters at least once a month. Another important monthly task Bookout highlighted was making sure the PTAC's front cover is properly connected with no air leakage.

Once a year, Bookout said hotels should perform a deeper clean on the PTAC unit. Upon removing the device from its sleeve, he said it should be put in a cart—possibly taken outside into the hotel parking lot—and sprayed down with a hose and water. After cleaning the devices coils and removing any accumulated dirt, insects and debris, Bookout said it’s simply a matter of letting the device dry and placing it back in the room.

Wheeler highlighted two mistakes hotels often make at this stage: not using a light cleanser and cleaning the machine with a power washer. While he said the PTAC generally is made of strong materials, he noted that caustic cleaners and high-pressure water can damage the unit.

Overall, Wheeler said a hotel’s best course of action is simply to follow the manufacturer’s recommendation. “You don’t have to necessarily reinvent the wheel,” he said.

Without performing these regular cleanings, Bookout said a hotel can shorten the lifespan of its PTACs and reduce its energy efficiency, costing it more on its utility bill and produce indoor air-quality issues, affecting guests.