PROJECT
hvac
PTACs May Hold Key To Hotel Energy Efficiency And IAQ
Especially in coastal markets such as Florida or Alabama, and elsewhere during summer months, a common concern among hotel engineers is the need for building ventilation where accurate control of ventilation air will help reduce mold and mildew.
Advances in PTAC technology help meet energy, comfort, and code requirements.
D
emand for fresh air, or makeup air, in hotel
ducted into each guestroom. Hotels employ
guestrooms is driven by several imperatives:
a packaged terminal air conditioner (PTAC)
the necessity for thermal comfort, improved
unit where first-cost-driven specifications
indoor-air quality (IAQ ), and building-code compliance.
demand lower cost or convenience.
Because hospitality is a service industry and hotel guests
The required features of a PTAC system
spend much of their time indoors, thermal comfort and
vary depending on the individual preferenc-
IAQ are especially consequential.
es of the specifying engineer. Some of the
When done correctly, introducing fresh air into hotel
most sought-after attributes include increas-
guestrooms results in healthier IAQ , fewer airborne
ing fresh air, controlling temperature, and
pathogens, and a lower risk of sick-building syndrome.
reducing mold, mildew, noise, and humidi-
“I would tell you that fresh air has been front-burner
ty. Expenses associated with PTAC units
for me for years,” explained Terry Smith, vice president of
include capital and operational expenses as well as main-
ventilation where accurate control of ventilation air will
Engineering Global Design Strategies at Marriott Inter-
tenance costs.
help reduce mold and mildew.
national Inc., Bethesda, MD (marriott.com). “When you
Interviews with hotel engineers found that solutions
“When you don’t control the amount of ventilation
don’t control outside air in buildings, it leads to signifi-
to improve IAQ are property specific, with few being
air that you have coming in, you spend extra money,”
cant temperature and humidity control problems for
equally effective for any two hotels. While demand for
said Lew Harriman, director of research & consulting at
guests and increases the chance of bacterial growth.”
PTAC systems must adhere to ventilation codes, engi-
Mason-Grant, Portsmouth, NH (masongrant.com), “It’s
neers look at ventilating buildings holistically.
expensive to take the humidity out if you don’t keep it
Many solutions are available to meet the need for makeup air and improve IAQ. However, some of these
“There are always variables,” explained John Seipp,
solutions come at the cost of increased energy load. Effi-
vice president, Capital Planning & Project Management
ciency is vital because, according to Blair Hildahl, princi-
at Marriott.
out to begin with.” Engineers look to reduce humidity to a 55% RH at 68 to 70 F —the temperature at which water vapor condenses. Favorable humidity conditions range from 55% to 60%
pal with Base4, LaCrosse, WI (base-4.com), guestroom energy consumption accounts for approximately 40% to
VENTILATION FOR HUMIDITY CONTROL
relative humidity. At higher dew points, people feel
80% of a hotel’s total building energy use.
“Fresh air gives an immediate feeling of clean, cool, and
“sticky” because the increased water vapor in the air slows
calm—which is exactly the guest experience hotel owners
the evaporation of perspiration on skin.
COST-EFFECTIVE MAKE-UP AIR
want to give their guests,” said Blair Hildahl of Base4.
“We want to keep the humidity below 60%,” ex-
To bring fresh air into guestrooms, select-service hotels,
Especially in coastal markets such as Florida or Ala-
plained Rick Frey, senior director, Engineering Support
such as Marriott Courtyard or Hilton Garden Inn, pre-
bama, and elsewhere during summer months, a common
Architecture & Construction at Hilton Hotels & Resorts,
fer a dedicated outside air system with make-up air, hard
concern among hotel engineers is the need for building
located in McLean, VA (hiltonworldwide.com). “You
commercialarchitecturemagazine.com
MARCH 2018
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