How about all of the above.

System Interplay

One forum participant, who works with a system manufacturer that deals with the hospitality industry, questioned whether there is inadequate design guidance, especially regarding pressure airflow management.

(Note: To promote a free exchange of ideas, ASHRAE forum attendees are not identified by name.)

An engineer commented that hotels often to reduce the amount of outside air brought in to lower their operational costs; they are not using the systems as designed.

Another engineer pointed out that most hotels have ptac’s in each room. These units, he observed, tend to be oversized so that they hit their design temperature very quickly but they don’t provide adequate dehumidification. “Sizing is a major contributor” to IAQ problems, he said.

A filter manufacturer pointed out that customers wouldn’t sleep in a room where they don’t change the sheets; why isn’t similar care provided for air-handling and filtration systems? “They need to maintain systems much more vigorously,” he said.

Instructions for maintenance people is within the scope of ASHRAE, added another attendee. However, “When we get down to requiring and enforcing maintenance, that’s a BOMA [Building Owners and Managers Association International] function.” What needs to be established by some regulating body is the frequency with which hotel hvac maintenance is performed.

An attendee from an industry related to hospitality suggested that ASHRAE provide a home for hotel hvac maintenance information. He added that the society should propose a tiered system of minimum maintenance levels and higher levels for hotels that want to raise the bar of IAQ for their guests.

Then there are problems with public spaces: meeting rooms, such as those in which ASHRAE forums are held. Temperature becomes an issue, pointed out a consulting engineer. “In meeting rooms, you never know whether or not to bring a sweater.”

Another pointed out that pressure relationships and airflow distribution come into play in the public spaces. “Not all problems are solvable with mechanical ventilation, but many are,” he said.

A manufacturer’s rep reminded the forum that unit accessibility and placement affect how often they are maintained. Too often, systems are jammed into virtually inaccessible locations in order to maximize rentable square footage.

Another attendee questioned why ptac’s are installed so frequently. This is mainly based on their lower installed cost and industry acceptance, it was pointed out. When one engineer proposed something more elaborate, the owner replied, “Nah, this works.”

However, without proper maintenance, they also become a source of humidity, mold growth, and odor problems. In such cases, it would be helpful to have information to present to the owner about the risks of inadequate maintenance and guidelines for proper maintenance. “He probably won’t take them,” said a consulting engineer, “but at least when things go wrong, you can say, ‘What did you expect?’”

Another forum attendee proposed that some enterprising maintenance contractors put together a package for ptac maintenance that includes pulling old systems from their locations, putting in newer or freshly maintained units, and taking the old systems back for routine maintenance. Ptac’s could be cycled and maintained regularly, and steady, profitable work would be created for the maintenance firm.

A consulting engineer observ-ed that unfortunately, “Owners have a use-it-and-dump-it attitude regarding their buildings.” When the building that once was a Hyatt ages, it is remodeled and sold to Holiday Inn, eventually becoming a Motel 6.

“You can have the best-designed, best-installed system in the world, but without maintenance, it’s going to develop IAQ problems,” pointed out another engineer.

Market Forces

There was one study performed by a ptac manufacturer and hotel chain, which resulted in a modified ptac unit that could bring in sufficient outside air, with high enough horsepower to provide adequate filtration.

However, the hotel chain declined to install the units because there were not enough complaints to justify the change.

In short, “We don’t know the costs to hotels of odor and IAQ problems. If there isn’t enough of a market force, change won’t happen.”

Publication date: 07/23/2001