PR FOR PLANET EARTH™

A REPORT ADVOCATING FOR SOCIALLY RESPONSIBLE SUSTAINABLE DEVELOPMENT

CRITERIA FOR EVALUATION: SELECT-SERVICE HOTEL ENEREF INSTITUTE EXAMINES TECHNOLOGIES AVAILABLE FOR SELECT-SERVICE HOTELS.

Demand for fresh air, or makeup air, in When done correctly, introducing hotel guestrooms is driven by several fresh air into hotel guestrooms results in imperatives: the necessity for thermal healthier IAQ, fewer airborne comfort, improved indoor air quality, pathogens, and a lower risk of sick and building code compliance. Because building syndrome. hospitality is a service industry and hotel guests spend much of their time indoors, and IAQ are especially consequential. SURVEY of HOTEL ENGINEERS “I would tell you that fresh air has been front-burner for WHAT ARE THE MOST IMPORTANT REQUIREMENTS FOR YOUR IAQ SYSTEM TO ADDRESS? me for years,” explained Terry Smith, VP of Engineering Global Design Strategies at Marriott International, Inc. “When you don't control outside 15% air in buildings, it leads to significant temperature and control problems for guests and increases the 35% chance of bacterial growth.” 15% Further, scientific studies have demonstrated that building occupants who work in spaces with adequate levels of properly delivered 10% 25% fresh air are more productive.

Many solutions are available to meet the need for

makeup air and improve TEMPERATURE FRESH AIR HUMIDITY

IAQ. However, some of MOLD & MILDEW NOISE these solutions come at the cost of increased energy cost-driven specifications demand specific, with few being equally load. Efficiency is vital because, lower cost or convenience. effective for any two hotels. according to Blair Hildahl, While demand for PTAC systems Principal with Base4, guestroom The required features of a PTAC must adhere to ventilation codes, energy consumption accounts for system vary depending on the engineers look at ventilating approximately 40% to 80% of a individual preferences of the buildings holistically. hotel’s total building energy use. specifying engineer. Some of the most sought-after attributes “There’s always variables,” PTAC UNITS DELIVER COST- include increasing fresh air, explained John Seipp, Vice controlling temperature and President, Capital Planning EFFECTIVE MAKE-UP AIR reducing mold, mildew, noise and & Project Management at To bring fresh air into guestrooms, humidity. Expenses associated Management at Marriott. select-service hotels, such as with PTAC units include capital Marriott Courtyard or Hilton Garden and operational expenses as well IMPORTANCE OF Inn, prefer a dedicated outside as maintenance costs. VENTILATION FOR air system with make-up air, hard HUMIDITY CONTROL ducted into each guestroom. Hotels Interviews with hotel engineers employ a packaged terminal air found that solutions to “Fresh air gives an immediate conditioner (PTAC) unit where first- improve IAQ are property- feeling of clean, cool and calm—

RESEARCH COMPILED AND PROVIDED COURTESY OF ENEREF INSTITUTE • WWW.ENEREF.ORG • COPYRIGHT© ENEREF INSTITUTE • ALL RIGHTS RESERVED which is exactly the guest Beyond humidity control, energy “Fungus and molds go hand- experience hotel owners want efficiency is especially desirable in-hand with ventilation and to give their guests,” said Blair in markets where potential humidity control,” said Lew Hildahl of Base4. government tax rebates or power Harriman of Mason-Grant. utility rebates are available. Especially in coastal markets Buildings are now constructed However, just as important as such as Florida or Alabama to comply with tighter standards efficiency is guest experience, (and elsewhere during summer than in years past. While the including the noise level and months), a common concern airtight infrastructure offers aesthetics of the PTAC unit. among hotel engineers is the superior insulation and energy need for building ventilation “Give me a $400 PTAC that’s efficiency, it can also lead to a where accurate control of extremely noisy and I’ve lost,” said lack of fresh air indoors. ventilation air will help reduce Marriott’s John Seipp. (Most PTAC mold and mildew. chassis are in the $600 range). HAZARDS OF “When you don’t control the UNCONDITIONED amount of ventilation air that VENTILATION AS MEANS VENTILATION AIR you have coming in, you spend OF MAXIMIZING COMFORT Select-service hotels often extra money,” said Lew Harriman, AND HEALTH specify PTAC units—designed Director of Research & Consulting Fresh air is needed to reduce by manufacturers to specifically at Mason-Grant. “It’s expensive to humidity, toxins and pathogens target the hospitality market— take the humidity out if you don’t inside hotel guestrooms. because of their lower cost. keep it out to begin with.” “The more ventilation you To introduce outside air into the Engineers look to reduce humidity provide, the lower the guestroom, PTAC units have to a 55% RH at 68-70 degrees concentration of whatever traditionally incorporated a tiny Fahrenheit—the temperature at contaminants there might be,” lever, or fresh-. However, which water vapor condenses. said Roger Hedrick, Principal the air in these systems is neither Favorable humidity conditions Engineer with NORESCO. measured nor conditioned. range from 55% to 60% relative Rather, it’s simply raw, hot, humid humidity. At higher dew points, Toxic chemicals include carbon outside air, which forces the people feel "sticky" because monoxide, radon, volatile organic PTAC units to work harder and the increased water vapor in compounds (VOCs), elemental worsens indoor comfort levels by the air slows the evaporation of particles, smoke and manmade introducing unconditioned air into perspiration on skin. fibers, and they can show up the indoor loop. everywhere from furniture and “We want to keep the humidity carpet backing to rooms heavily below 60%,” said Rick Frey, Senior sprayed with pesticides. WHY HOTELS SPECIFY Director, Engineering Support PTAC UNITS Architecture & Construction at Living pathogens—found naturally Despite the problems that Hilton Hotels & Resorts. “You in the environment—include unconditioned air can introduce, don’t want the bed sheets to feel molds, mildew, dust mites, spores, for many hotel chains, the damp.” pollens, bacteria, microbes and benefits of PTAC units far viruses.

RESEARCH COMPILED AND PROVIDED COURTESY OF ENEREF INSTITUTE • WWW.ENEREF.ORG • COPYRIGHT© ENEREF INSTITUTE • ALL RIGHTS RESERVED outweigh the disadvantages, systems. That limitation, however, increased resistance to flow and especially with recent innovations is about to change. effectively cuts the CFM in half. for introducing makeup air. "With hot, humid air pouring into Typically, PTAC systems are MICRO-: a building," Marriott’s Terry Smith attractive, 42”-wide, self- A SOLUTION FOR explained, “I must be sure that contained, all-in-one package UNCONDITIONED AIR? the dehumidification section can wall units with plastic fronts; react fast enough to keep the To eliminate the problem of they’re installed below a window incoming airstream at roughly unconditioned, raw, humid outside in order to discharge directly room neutral — 70°F/50% RH.” air entering guestrooms through into the guestroom. These are the fresh-air door, Amana, GE, Lastly, as with any mechanical combination air conditioners and other PTAC manufacturers system, adding more moving designed to provide the heating have offered a solution: dropping parts may also increase and cooling for individual in an independent, miniature 6" by maintenance costs, energy load guestrooms. 4" preconditioning coil module. and noise level. Select-service hotels use Just about the size of a soup “I think the micro- is PTACs as an alternative to hard can, this micro-compressor sits a great idea. It is a cost-effective ducting outside air into all the on top of the primary system by solution,” said John Seipp, Vice guestrooms, where ceiling space the fresh-air door in the dead President, Capital Planning & in the corridor may limit the room space of the PTAC unit. When the Project Management at Marriott for work. level reaches about 60%, the micro-compressor kicks International, Inc. “However, it “Generally, the select-service on and dehumidifies the incoming probably is going to be noisier for hotels are relying on the outside air stream. the size and adds an additional air coming through the PTAC,” energy load.” explained Marriott's Smith. However, several engineers interviewed for this report Some PTAC manufacturers have expressed concerned over TAKING A STEP FORWARD lowered the carbon footprint the efficacy of such micro- WITH VARIABLE-SPEED of their units by using a more compressors—doubting, for INVERTERS efficient with a lower example, whether the PTAC One significant development global warming potential (GWP), miniature drop-in air conditioner in energy efficiency for the such as the refrigerant, R-32. module can bring a humid 35 next generation of PTAC units CFM at 95 degrees Fahrenheit to PTACs are also a more will be the introduction of 72 degrees Fahrenheit while also economical solution with advanced variable-speed inverter ringing out enough humidity to the advantages of low cost, technology. Compared to a make that space neutral. While easy installation and simple traditional constant-speed PTAC the fresh air “exhaust” fans on maintenance. One disadvantage, unit, a variable capacity inverter these systems are rated at 35 however, is that PTACs don’t reaches a set point faster and CFM (cubic feet per minute), employ the more efficient maintains precise temperatures the airflow may be hampered inverter-driven variable flow with minimal energy use. as it travels around various refrigerant (VFR) technology obstructions, which results in Constant-speed PTAC units run common with some larger

RESEARCH COMPILED AND PROVIDED COURTESY OF ENEREF INSTITUTE • WWW.ENEREF.ORG • COPYRIGHT© ENEREF INSTITUTE • ALL RIGHTS RESERVED I WOULD TELL YOU THAT FRESH In fact, Friedrich already markets AIR HAS BEEN FRONT-BURNER to the hotel industry an inverter- compressor VTAC (a vertical PTAC), FOR ME FOR YEARS. which Marriott has successfully TERRY SMITH | VP of Engineering at Marriott tested. VTACs are closet-mounted single-packaged units.

“We had Friedrich run some at full capacity and then shut off. amount of power required at any energy analysis for us on it,” said This stop-start cycle results in a given moment. Marriott’s Terry Smith. “It’s in the 2- higher power consumption than to 3-year payback. Can be upward This precision is especially helpful a variable-speed system. And to 4, but it’s pretty darn good.” because PTAC systems are often unlike variable-speed technology, specified for the worst-case constant-speed units create wide Friedrich brands the vertical unit scenario—oversized, for maximum temperature swings, because “VRP,” and according to Blair load. Inverter technology will when the unit is off, it is not Hildahl, Principal at Base4, the allow hotels more flexibility in dehumidifying or cooling until it VRP is highly effective at providing how they design. And because starts up again. in-room humidity control and sharp fluctuations in the load are addressing IAQ concerns. In variable-speed systems, on the eliminated, the life of the system Hilton’s Rick Frey agrees: “Most other hand, the inverter varies the should be extended. speed of the compressor motor PTACs and VTACs can control The disadvantage of inverter to continuously regulate the temperature, but any humidity technology is that until inverters temperature. At initial start-up, control is subsequent, or ancillary, become more common, they’ll the unit reaches a designated set to the temperature control. The add an additional level of temperature and then reduces Friedrich VRP unit specifically cools complexity for field repairs. capacity as the set temperature and addresses room humidity.” is achieved by slowing the compressor speed, which in turn EFFECTIVE, ENERGY- TECHNOLOGY INNOVATION: drops the refrigerant flow rate. EFFICIENT INVERTER- INVERTER PTAC The compressor never shuts off COMPRESSOR VTAC completely. The system maintains Similar to Friedrich’s VRP vertical According to Marriott’s Terry the set temperature by constantly unit, the new Friedrich inverter Smith, a significant advance in monitoring the capacity needs— PTAC unit brings in fresh outside PTAC technology is about to ramping up or down to meet those air through a distinctively unique change the industry’s thinking. needs based on the demand. method. The Friedrich PTAC bypasses the constraints of the “Friedrich now has an inverter- Because variable-speed inverters secondary 6-inch coil module, compressor PTAC unit on work at a lower capacity, on opting instead to blow fresh air the market,” explained Smith. average, less power is consumed, across the primary coil. “Because of the inverter- offering quieter operation and compressor technology, the significant energy savings. Rather than a separate micro- energy savings you get are Inverters allow the system to compressor—as other PTAC unbelievable.” consume only the exact minimum manufacturers employ to

RESEARCH COMPILED AND PROVIDED COURTESY OF ENEREF INSTITUTE • WWW.ENEREF.ORG • COPYRIGHT© ENEREF INSTITUTE • ALL RIGHTS RESERVED precondition the incoming fresh guestroom or an outdoor air community is short-term, first- air—the Friedrich inverter PTAC PTAC/VTAC unit. cost driven, to the point that pulls the outside air, unrestricted, payback from energy efficiency Hotel franchises, such as Hilton, up through the series of fans and ranks far down the ladder of Marriott, IHG and Hyatt, meet— introduces it to the front primary importance. and sometimes exceed—ASHRAE evaporator coil that is already minimum fresh air ventilation doing the normal workload of the rates for hotel guestrooms. SIGNIFICANT ENERGY system. To achieve LEED certification, SAVINGS AND MAKE-UP AIR “We should get the same benefits buildings should comply with NOW IN THE HANDS OF THE out of the inverter-compressor PTAC ASHRAE minimum fresh air HOTEL INDUSTRY that you get out of the inverter- requirements. With nearly 5 million guestrooms compressor VTAC once its available,” “In most cases, the codes are in the US, the hotel industry holds said Marriott’s Terry Smith. based on ASHRAE standard, a tremendous opportunity to The efficiency of the Friedrich so we would not want to go reduce America’s overall energy unit is twofold: the system less than ASHRAE standard use. The number of installed eliminates the secondary micro- because doing so may not PTAC units is expected to grow compressor found in other comply with local codes,” said significantly, along with the systems, and it is also the first Hilton’s Rick Frey. growth of the industry itself. variable refrigerant flow, inverter- More efficient PTAC units compressor PTAC unit on the MARKET SEGMENTATION should be a logical inclusion in market. As the units should Very few major hotel brands own high-performance buildings. They therefore bring in more outside their building assets. While some are inexpensive first-cost units, fresh air, they will lessen the assets not owned by the hotel with simple maintenance, in which requirements for dedicated brand are still managed and downtime affects only rooftop make-up air systems— operated by the brand one guestroom. allowing a downsizing of the (who are thus incentivized whole building make-up air. With the latest PTAC technology to optimize energy savings), providing low-cost ventilation, the majority of hotel building thermal comfort and humidity MEETING ASHRAE assets in the US are franchise control, the hotel industry can MINIMUM STANDARDS properties, paying royalties and seize this opportunity and take Building codes require fees to the hotel brand. a leading role in HVAC energy “ventilation for acceptable The select-service product market reduction, globally. indoor air quality” in a has grown very price-competitive guestroom whenever the space in recent years. About 2,800 is occupied. There are two investment ownership groups primary methods by which hotel have possession of almost all owners meet ASHRAE and ICC/ franchise properties. Investors IBC code requirements: a full include pension funds, LLCs, dedicated outdoor air system insurance companies and owner- (DOAS) directly ducted to the developers. The investment v56-10

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