Commercial Architecture March 2018 - 47

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.

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

COMMERCI A L A RCHI T EC T URE

http://www.marriott.com http://www.masongrant.com http://www.base-4.com http://www.hiltonworldwide.com http://www.commercialarchitecturemagazine.com

Table of Contents for the Digital Edition of Commercial Architecture March 2018