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In the past decades, we have been made aware of the drastic changes occurring in our living environment. As a result, people have started modifying their individual way of life hoping to avoid catastrophic consequences, especially in the wake of recent climatic disasters all over the world. However, the modifications that we, as a community, have made in our lifestyle and consumer culture have not been enough.
Being in the hospitality industry I feel that, as a window of global interactions and exchanges, upscale hotels should be contributing to the common cause and start acting as a role model to enforce social and environmental changes towards sustainability. With the help of high-technology and commitment, the future of hospitality must be looking towards energy self-sufficiency and becoming as neutral and even beneficial to our ecosystem as living plants.
This is also the objective of our concept. The basis of which is to use environmentally friendly materials and techniques to build "living" hotels, capable of self-generating electricity through renewable energies as well as capturing, recycling and treating their own water.
Please refer to the appendices for our target market and the green measures applied.
The major financial detail for investors is our concept's heavy start-up capital investment but with time it results in a high profit margin due to energy independency and low labor cost.
Whereas my previous work was intended for the very specific Vietnamese market, I choose a different approach for this particular dissertation, its aim being the implementation of a hotel franchise on one hand, and the applicability of a basic yet fixed set of structured criteria to any chosen market on the other hand.
New challenge: development of a hotel group
"Business is business" but I also want to spread the concept globally in order to improve society and everyone's living conditions.
Even if the previous project proves to be a success I can not help but notice that customers choose our hotel because of hype, new high-tech amenities and adequate prices although they are still skeptical about ecology. We are aware of this because if the competition elsewhere offers cheaper alternatives then customers especially those not yet loyal are ready to leave us, especially the business clientele.
Therefore we urgently need of guest education and guest loyalty.
I believe if we can make the concept bigger then the impact on people will be bigger. A concept with buzz becomes a trend, which becomes a behavior, which becomes habits and loyalty. And also because it makes sense financially to replicate the concept worldwide, I thus aim to create an international hotel group.
This work is based on the simple observation that, although many individually-owned eco-friendly hotels have developed all over the world these past years, most of them take the form of new buildings set outside of the big cities, in environments where a low ecological impact is a lesser challenge than, for example, Hong Kong or Singapore. One can also acknowledge the lack of wholly eco-friendly and sustainable hotel groups, particularly on an international scale. This can be seen as the consequence of two main difficulties: the high anticipated costs of such an initiative in the hospitality sector, the ecological constraint being often perceived as the source of many expenses; and the non-eco-friendly nature many urban buildings, increased by the "urban heat island effect" which contributes to higher pollution risks and the degradation of air and water quality.
However, this paper's target is to show that the operating costs minimization and income maximization are actually compatible with the reduction of energetic costs and environmental impacts, as the concept of "sustainability" tends to join these two aspects which are in actual facts complementary. Indeed, both are based on a great care to the hotel's construction and day to day operations, by the hotel's managers, employees, suppliers as well as clients.
To me, it appears that the implementation of an eco-friendly hotel group concept on an international scale can be the perfect ally to a high economic competitiveness.
The objective of this guidebook, taking roots in the potential success of the first self-sufficient hotel in Vietnam which was the core of my previous work, is to develop a franchising concept which can be altogether sold to potential investors or hotel owners around the world, with the idea of creating the first international and sustainable urban hospitality group.
Because of the importance of this project's scope and of the vast number of points of views required for the implementation of such a group, I chose to develop this work during two different stages, which will in turn produce two distinct papers:
This first paper will be focused exclusively on the criteria and techniques which should be applied to both the construction and the operation of each hotel, in order to homogenize and standardize them into a group and to make this concept potentially relevant to any type of market. For both new hotel projects and buildings in reconversion, we will be drawing guidelines, ecological procedures on one hand with specific and easily applicable initiatives, and cost-cutting, income-maximizing management solutions on the other hand. The latter is purposely done in form of ready-to-use questions aiming to guide a franchisee's practical issues. Please also refer to the glossary for technical terms.
Each of these standards and solutions will be modeled into a certification/grade system which will give precise information on the integration of each hotel to the franchise. This assimilation will be complete only when the hotel will have attained a minimum of 90% of the provided criteria.
As important as ecological standards is the group's responsibility towards the society. A particular department is thus worth mentioning at the end of our paper.
The second and last section of my work, which will be written in 2013-2014 at the conclusion of my MBA at CMH, will consist in the study and proposition of ecological marketing, revenue and sales strategies at the group's scale.
Sustainable building standards
According to the US EPA, developed land use in 2004 was equal to around 108 million acres. "This was an increase of 24% over the previous 10 years. This trend is replicated throughout much of the world as populations grow and migrate to urban areas of the world.
With this growth, land that could have been put to other uses is lost. These uses could include land for growing food, and diversified ecosystems. As paved areas grow, rainwater is no longer attenuated at the point of contact with the ground and immediately runs off taking contaminants and eroding soil. Waterways get polluted.
Developed land tends to consist of a high percentage of hardscape - such as parking areas and building roofs. These are heated by the sun during the day and re-emit that heat at night which can raise local air temperatures. This can increase air conditioning loads for a building and also impact insects and other wildlife.
A site should be chosen, designed, and constructed, to minimize the impacts listed above. The social impact of the site should also be considered along with the ease of access to those working at the site."
Environmentally sensitive site management
The environmental implications of the management of a hotel site can be profound. Often chemicals used for pest control, fertilizing, cleaning walkways, or removing ice end up polluting the ground or waterways and affecting local flora and fauna. The implementation of a comprehensive site management plan can lessen this impact whilst also improving conditions for guests and workers by ensuring that the frequency of site maintenance work is kept to a minimum and eliminating potential exposure to toxic substances.
The site management plans relate to the following issues:
â€¢ Maintenance equipment
â€¢ Snow and ice removal
â€¢ Cleaning of building exterior and hardscapes
â€¢ Paints and sealants used on building exterior
â€¢ Outdoor pest management
â€¢ Erosion and sedimentation control
â€¢ Composting or mulching of landscape waste
â€¢ Minimization of chemical fertilizer use
A site management plan should be implemented at the onset of construction to minimize the impact to the building site. In particular, an erosion and sedimentation control plan is necessary to control and minimize the introduction of silt and pollutants into the watershed during rain events. Projects with new site or landscaping work should follow the suggestions in the referenced stormwater pollution protection guidelines appropriate to the project site.
Reduction in the use of toxic chemicals on the hotel site is a low-cost measure that will deliver immediate environmental benefits. Erosion and sedimentation control should be performed for all landscaping work. Mulching or composting of landscaping waste should be done where possible to reduce waste hauling and fertilizing costs.
Construction and tourism can be very disruptive to local ecosystems and endanger the natural resources that make a location a desirable destination. Whenever possible, choosing a building site that has already been disturbed and/or is not home to sensitive species is the first step to reducing the negative impact of increased human activity in an area. Landscape and site planning should protect native species with wetland buffers, wildlife corridors and habitat restoration. Trained tour guides and other means of signage and visitor education should be employed to limit damage to protected areas  2.
Language explaining proper site preparation and maintenance should be included in specifications. All projects could practice site and species protection starting with a basic ecological audit that will inform site design and use.
Consideration should be made for habitat restoration when designing new landscape features and guides and/ or education for guests visiting ecologically fragile areas should be provided
Well planned solar orientation balances the need to block sunlight from contributing to cooling loads and permits penetration for day-lighting and solar heating. Orienting the building so that the longest facades are exposed to the North and South with appropriate shading allows the project to take greatest advantage of available solar resources.
By designing the most efficient building footprint that meets occupancy and operating requirements resources are conserved during construction and operation of the facility. Building for possible expansion that is not ultimately used only results in higher initial capital cost as well as higher facilities costs. Reducing the building footprint also allows more of the site to be utilized for landscaping and habitat restoration  4.
When minimizing the footprint of a project determines functions, such as event parking or large meeting halls, can be shared with neighboring facilities or stacked. When optimizing solar orientation, incorporate appropriate horizontal and vertical solar shading devices on the exposed facades.
Existing projects may only pursue this action if expansions are planned. When expansions are being planned, first determine what neighboring resources could be better utilized in lieu of new construction.
Ecology and landscaping
Plan the building footprint, driveway and parking to maximize open space and preserve local ecosystems. Green space should serve as a wildlife corridor and may be used for recreation or aesthetic gardens. Vegetation contributes significantly to other measures such as reduced heat island impact and stormwater control. Native vegetation species adapt to the geography, hydrology, and climate of the region, require little or no irrigation, minimal maintenance and require no fertilizers, pesticides and herbicides. Native vegetation act as local habitats to animal species in the region and create biodiversity. Vegetated open space is critical to threatened/endangered species.
If a site will be disturbed during construction such as filling wetlands, vegetation removal, soil compaction, then a restoration plan should be developed and the project must develop an Erosion and Sedimentation Control Plan based on the requirements in the group's Integrated Pest Management, Erosion Control and Landscape Management Plan.. The restoration plan can identify areas not to be disturbed, as well as procedures to ensure that the site is restored. The plan should illustrate the site before construction and the measures that will be taken during and after construction to restore habitats.
Disturbance outside the building footprint should be minimized. An ecological disturbance should be mitigated with a site restoration plan including developing habitats for plant and animal species. Urban environments may utilize plazas, courtyards, or even green roofs. Greenspaces in close proximity to the hotel may have secure wireless internet access enabling staff to work remotely. If there is sufficient open space, a plant with high calorific value could be grown as a biofuel.
Invasive and non-native species should be removed from the existing hotel grounds and replaced with native/ adaptive species. Landscape maintenance practices should minimize the use of chemicals, reduce the introduction of pollutants to stormwater runoff and reduce waste.
Reduce auto use impact
The environmental impact of transportation to and from the project can be significantly decreased with planning and programs that decrease single occupancy vehicle use. Guests and employees will benefit from programs those other alternatives to single occupancy vehicles.
Enabling employees and guests to utilize public transportation will lead to a reduction in automobile pollution, road development and parking requirements. Offering amenities such as discounted or readily available transit cards can increase ridership in areas where mass transit is available. Fuel efficient shuttles that service airports, train stations and mass transit stations can be employed in remote locations to discourage single occupancy vehicle rental.
Biking instead of driving reduces pollution, parking requirements, and provides a healthy alternative to traffic. Providing bicycle and fuel-efficient vehicle rentals on-site will allow guest greater flexibility while reducing car usage  .
Before considering a potential building or site location, the owner should thoroughly investigate local bus, train, and light rail transportation options. Parking plans should incorporate shuttle and carpool drop-off areas as well as provide ample secure bicycle storage for employees and guest rentals.
All projects can encourage employee use of alternative transportation by giving preferential parking to fuel efficient vehicles and carpools, providing bike storage and showering facilities, participating in mass transit discount fare programs and providing easy accessibility to mass transit.
Guest alternative transportations programs, with on-site rentals, shuttle services, maps and education, can be incorporated in part or in full depending on the location's resources.
Large vehicle storage lots cause many other environmental impacts beyond simply supporting single occupancy vehicle use. Surface car parking lots limit the amount of site available for habitat and management of stormwater. These large impervious surfaces cause excessive runoff which causes flooding, erosion and the introduction of pollutants into waterways. The dark surface of the pavement is also a major contributor to the urban heat island effect that changes the microclimate of areas. Heat islands are characterized by a thermal gradient between developed and undeveloped areas. Heat island impact can be reduced by shading hardscape and using open grid paving systems or paving material with a solar reflective index (SRI) greater than 29  .
These environmental impacts can be reduced by minimizing surface parking and selecting environmentally preferable materials.
Shading with existing trees can be an aesthetically pleasing option that incurs no cost. Asphalt has a SRI of 0 while new white concrete has an SRI of 86. If financial or local circumstances provide no alternative to the use of asphalt, teams should consider the use of recycled asphalt where locally available and feasible. Paving options that allow for increased stormwater infiltration include pervious concrete, open grid pavers, gravel and structural systems that allow for periodic parking on grass  .
Required parking should be minimized through alternative transportation programs, where applicable. Parking area should be shaded with trees or placed under a structure with a high albedo roof. Surface parking should provide rainwater infiltration through pervious paving materials. Materials used to construct new parking should be light colored and/or have high recycled content.
Projects with existing parking spaces should not create additional parking. Parking should be shaded with trees and/or resurfaced with a lighter colored material, such as white topping.
The building envelope is used to maintain occupant comfort and regulate indoor environmental quality. The envelope consists of roofs, walls, windows, doors and floors.
In general, the following attributes should be considered for each climate zone:
Materials with high thermal mass are favored, along with external insulation. Concrete, masonry and adobe are all suitable materials. Adequate thermal mass will absorb solar heat during the day and release the heat at night. Finishes with high reflectivity and wall shading should be used to reduce solar gains. Use plants and other devices for external shading.
Materials with low thermal mass are favored. In some cases, masonry is used because of its durability. High reflectivity materials are suitable. Use plants and other devices to shade the building.
Materials and construction vary for specific climate conditions and heating/cooling strategy.
Generally, a conventionally heated building should not have high thermal mass, as this can increase the time required to meet thermal comfort conditions. However if solar heating will be used, a high thermal mass can be advantageous. Envelopes with low infiltration and optimized insulation are very effective for this climate.
Optimize day-lighting design
Windows provide a visual connection with the outdoors, natural light and solar heating. Optimizing glazing materials and window design can have a significant impact on increasing building energy performance.
Use of low-E coatings and double-paned windows can improve glazing thermal performance. A Low-E coating is a metal film, which reduces the emissivity of glass (or the "E" in low-E), and thus the amount of heat that is lost or gained (transmission). Windows manufactured with Low-E coatings typically cost 10%-15% more than regular windows, but reduce energy transmission through a window by 30%-50%.
The size and orientation of windows must also be considered. Typical window to wall ratios range from 20% to 50% and should be optimized for location.
Shading strategies should be considered in the design process. Optimally designed shading will allow sunlight penetration during heating periods and block it during cooling periods.
To maximize energy savings, optimized day-lighting design should be combined with photo sensors linked to the artificial lighting in the building. The generally accepted goal for daylight, which is defined by the BRE and the USGBC, is to design for 75% of regularly occupied spaces to achieve 25 foot-candles (250 lux) of illumination from daylight on the task plane  9.
Low-E, double glazed windows may be applied to an entire hotel or to specific orientations. This is most beneficial in extreme climates and in guest rooms with large windows. The shading design will depend on climate, latitude and building layout. Shade planting should be considered
Replacement of existing windows should be considered when remodeling existing hotels 30 years or older. Installation of shading devices in existing hotels is costly and generally only appropriate in refurbishments. Interior shading such as curtains can be used in other cases
Optimize façade design
The façade design of a building not only determines its external appearance, but can also have a large impact on energy consumption. Efficient design is dependent on a number of factors, including climate and the building's mechanical systems. Through analysis of energy savings and costs, wall insulation can be optimized for any building and climate.
Generally more insulation is desirable in climates with extreme temperatures: hot, cold, or both. In cold climates, insulation reduces heating costs. In hot climates, it minimizes air conditioning costs. In temperate climates where natural ventilation is appropriate, too much insulation may increase energy costs. Therefore, optimization of insulation should be performed on a climate by climate basis  .
Thermally broken façade details can also be used, typically in cold climates, to reduce heat flow. A piece of insulating material is used to separate interior and exterior details, for example aluminum spacers in glass panels, thereby reducing heat flow across the panel  .
Climate must be considered when designing façades. In very cold climates, well insulated façades with thermally broken details are most appropriate. In hot, arid climates, green façades should be considered. In each case, the building's façade and mechanical systems must be considered together.
Retrofitting of a different façade system is only appropriate if a major refurbishment is being undertaken, and the building is greater than 30 years old. Installation of insulation in existing buildings is also far less cost effective than for new construction.
Cool roofing systems
The term "heat island" refers to urban air and surface temperatures that are higher than nearby rural areas, caused by the high density of dark roofs and paving that absorb heat. The elevated temperature associated with heat island effect leads to increased building cooling loads.
A roof with high solar reflectivity, typically white in color, is called a cool roof, and can be used to reduce heat island effect. Reflective cool roofs can reduce roof surface temperatures by up to 100Â°F. This will in turn lower the cooling energy used by a building. Another benefit of the cool roof is that the lower temperature will cause less expansion and contraction of the roof materials, extending their useful life  13.
Hotels located in urban areas are most likely to be impacted by heat island effect. Cool roofing systems may offer significant benefits in terms of comfort and cost. Packaged rooftop air conditioners will operate more efficiently on a cool roof than on a traditional roof  .
Hotels in temperate and hot climates, especially in urban areas, should consider a cool roof when roof replacement is being done.
Air infiltration reduction measures
Infiltration of untreated outdoor air to indoor spaces occurs when a building's indoor pressure is less than the outdoor air pressure. This causes outdoor air to "leak" in the building, via cracks around doors and windows and even through exterior walls.
This outdoor air has not been conditioned or dehumidified, resulting in uncomfortable temperatures and humidity levels. If the outdoor air is humid, condensation can form on cold surfaces. This can cause mildew and other problems. Unfiltered outdoor air coming can also carry particulates and dirt.
To minimize infiltration, the filtered outdoor air brought into the building must be supplied to create a positively pressurized building. This will cause air to push out of the building rather than in. Additionally, the construction of the building should be weather tight, using well-built doors and windows with weather-stripping around them.
For larger resorts with high square footage, building pressurization controls can be used in conjunction with a building management system. The pressure sensors will report when pressure has fallen below the acceptable levels and the BMS relays to the air-handling unit to supply more conditioned air, thus increasing the pressure and avoiding infiltration.
All new hotels should be built with construction materials that minimize infiltration and should be positively pressurized using a mechanical system.
Weather stripping should be installed on existing doors and windows, and all cracks and building envelope failures should be repaired.
Noise is defined as being "unwanted sound". It has the ability to disturb sleep and cause stress. In general, noise in buildings comes from 3 sources:
(a) environnemental (trafic, adjacent activities, construction, etc)
(b) building operation (noise from MEP services)
(c) occupational (from human activity).
The combination of noise from all of these sources must be appropriately mitigated and balanced to achieve success in hotel design. This requires an integrated design approach.
The criteria and metrics vary between spaces based on function (bedrooms, lounges, offices, spas etc).
Appropriate shell and core, wall, floor and façade acoustic performance should be considered. Ventilation approach should also be considered. Successful acoustic design is achieved by separate noise producing spaces (mechanical rooms, kitchen, elevators, garbage and laundry shoots, etc) from quiet spaces (bedrooms, lounges, etc) horizontally and vertically.
Acoustic issues should be considered during major refurbishments or retrofits.
Mechanical systems present many opportunities to save energy, resources, and money. In addition, mechanical systems can help achieve improved comfort and air quality for guests. The appropriate mechanical systems and equipment for a project are dependent upon several factors including:
â€¢ Types of rooms and their clientele
â€¢ Orientation of building
â€¢ Availability of parts, equipment, and skilled labor
Mechanical systems may be active or passive and appropriate conditions and improved efficiency can be achieved through both equipment and controls. To determine the correct HVAC systems and accredited actions to use for a new hotel, it is recommended that an energy audit of an existing similar hotel in the same climate zone be done. This will reveal which strategies could present the most savings. The accredited actions should not all be done together, in fact, some would be counter-productive depending on the climate zone.
Fresh air delivery
Outdoor air in hotel rooms is often delivered to hotel rooms using through the wall air conditioning units. These units are often not well-equipped to handle a high heat load, sometimes resulting in excess humidity, mould, and poor air quality.
Supplying the outdoor air to hotel rooms through a central system allows for better control over the temperature, humidity and amount of outdoor air to each room, creating a more comfortable environment. A central unit allows for ease in maintenance and creates fewer disruptions in guest rooms. It also controls building pressurization, which can help prevent infiltration.
If the hotel has a building management system, then demand ventilation may also be implemented to reduce ventilation rates when a room is unoccupied by use of a control system and CO2 sensors. This can produce energy savings of approximately 10%.
Displacement ventilation supplies air at low levels and uses the natural buoyancy of air to raise heat and contaminants to the exhaust at the top of the room. Supply air can reduce cooling, heating and fan energy consumption by supplying air from an under-floor plenum or mechanical chase at low velocity, at a temperature closer to the desired room temperature, compared with conventional overhead systems.
A minimum indoor air quality must be provided for all occupants - staff and guests. ASHRAE Standard 62.1- 2007 mandates the minimum ventilation rates for new hotels. Existing hotels must meet these standards or provide at least 10 cfm per person.
The design of new hotels needs to allow for a central air handling unit and mechanical shafts for the ductwork to supply air to each room. This ductwork can be coordinated with bathroom exhaust shaft s. Control of air distribution should be integrated with controls dampers, guest room master switching and CO2 sensors if such systems are in place.
All new ventilation systems must be designed and installed to meet ASHRAE Standard 62.1-2007 for minimum outdoor air rates, and tested to prove compliance  .
Central air distribution often requires a new mechanical chase to be built to each guest room, which is not practical unless a total architectural and mechanical renovation is being done.
Hotels that have been constructed or undergone commissioning in the last 5 years can use this documentation to show that outdoor air rates meet ASHRAE 62.1-2007. Otherwise, testing of the air handlers must be performed by either the hotel engineer or a third party testing and balancing technician.
Hotels that cannot meet ASHRAE 62.1-2007 must show that at least 10 cfm of outdoor air per person can be supplied under all normal operating conditions.
To save energy, modern air conditioned buildings typically re-circulate used room air, which can diminish indoor air quality and can affect occupant comfort and productivity. Using natural ventilation in appropriate weather can reduce building energy use and improve occupant comfort. Typically, natural ventilation can be used to ventilate up to around 6 meters (18 feet) depth from a window, or a floor plate depth of up to 12 meters
(40 feet) for cross ventilation.
In summer months the temperature difference between inside and outside will be small and very little cooling effectiveness will be available. Efforts should therefore be made to minimize heat gains to the building through:
â€¢ Shading, Light shelves / natural day-lighting
â€¢ Artificial lighting controls
â€¢ Increased insulation
â€¢ High efficiency glazing
â€¢ Wind investigations
Due to the expectations of hotel guests, it will not be feasible to use natural ventilation for the whole year. In most climates, the building will have to use conventional heating and cooling systems for peak winter and summer periods. Natural ventilation may also be unsuitable in areas with year-round extreme temperatures or high humidity
Natural ventilation can be incorporated by including operable windows in each guest room with an exterior wall, in conjunction with A/C lockouts when windows are open. The amount of energy saved will depend on climate and the willingness of guests to open the windows. In common areas such as foyers, careful design is necessary to ensure minimum levels of outside air are delivered. Natural ventilation should only be used when it can provide comfortable conditions. On extreme days, the central ventilation unit should be used instead.
Installation of operable windows and A/C lockouts should be considered in rooms where the climate is suitable. Conversion of larger areas such as foyers to natural ventilation/mixed mode operation can be complex and costly and would typically only be undertaken as part of a redevelopment/redesign.
Guest room HVAC equipment selection
In hotels, guest rooms are often served with using through the wall heat pump units (PTACs). These are easy to install on a room level because they do not require piping, they do not require a separate outdoor compressor unit, and they do not require ductwork. Unfortunately, most units do not provide tight temperature or humidity control, are often noisy, and are energy inefficient.
Providing guest rooms with better HVAC units would achieve higher guest comfort, ease maintenance, and save energy. The type of hotel, the climate zone it is located in, the orientation of the exterior rooms, and the layout of the overall building must be considered before picking the system that is right for the hotel.
Water source heat pumps are typically 25% more efficient than PTACs and use a condenser water system. They are easy to install and inexpensive, but still not as efficient as other systems that can be used.
Four-pipe fan coil units provide cooling and heating from a central plant piped to the guest rooms, which provides better energy efficiency than PTACs and better temperature control and lower noise. They offer an improvement in energy efficiency of approximately 15%.
A variable-air-volume (VAV) air-handling system would require a central air-handling unit that would be ducted to VAV boxes in each room. The VAV boxes would open and close in response to the thermostat in each room. The outdoor air could be supplied either through the VAV system or separately. These are generally the most efficient systems, offering energy savings of 25-30%. If the VAV system is selected in the cold or temperate climates, use of fan-powered parallel VAV boxes in the room will produce an additional energy savings by reusing room heat during the winter  17.
New hotels pose the best opportunity to integrate the best HVAC system for a climate, building type, and building size. VAV units require a ceiling cavity, while heat pumps and usually fan coil units require an architectural enclosure. VAV systems require a BMS and require commissioning and would only be applicable in large scale resorts.
As HVAC systems are upgraded or replaced, a more efficient system for that climate and hotel type should be used to ensure energy savings and better room conditions.
Water cooled chillers
In an air conditioning system, supply air removes heat from the spaces if the outside air is warmer than the required supply air temperature. Chilled water or another medium is used to remove heat from the supply air. The heat that is captured in the chilled water loop is then rejected by the chiller either directly to air or to a condenser water system that will reject heat using either a cooling tower or a dry cooler.
The difference in efficiency between air cooled and water cooled systems is climate and weather specific. The outdoor dry bulb temperature is the primary factor for air cooled systems and the outdoor wet bulb is the primary factor for water cooled systems.
When using a condenser water system, dry coolers are less efficient than cooling towers, so if a chiller is used it should be air cooled or have a cooling tower. At a certain tonnage of HVAC, it becomes more cost efficient to have a cooling tower and a water cooled chiller than an air cooled chiller. A rule of thumb is that for cooling loads in excess of 200 tons, a water-cooled system will likely be the best choice for the life of the system. The system in the modeled hotel had a cooling load of less 200 tons, yet using a water cooled chiller still yielded energy savings of approximately 10% over an air cooled chiller in hot/humid and hot/dry climates. The benefits in temperate and cold climates were negligible. Before deciding to use a water cooled chiller, system tonnage and climate should be considered  .
When compared to air cooled systems, purchasing a water cooled system will require a higher capital investment, mainly due to the cooling tower, condenser water pumps, and piping. They will also require additional maintenance, including specific water treatment requirements. For larger systems however, these downsides are usually offset by the overall energy savings.
This must be considered with regard to a number of other credits. Water cooled chillers will likely be appropriate for a large, centralized HVAC system, but are unsuitable for smaller systems. More detailed analysis is necessary based on weather and internal load data.
The difference in structure between air and water-cooled chillers makes conversion of existing systems difficult and costly, and should only be considered if replacement or extensive repair of an existing chiller is necessary.
Additional cooling systems
In some climates and hotel sites, innovative cooling strategies such as evaporative or absorption cooling can be employed to effectively save energy and operating costs over conventional air conditioning systems. These strategies can be complex and require thoughtful design considering the climate and usage of the building. To determine if any non-traditional system should be incorporated into a hotel, an energy model should be done to study the system and realize if both cost and energy use are reduced.
A direct evaporative cooling system passes dry outdoor air through pads kept moist through water saturation. Cooling is achieved because heat from the air is used to evaporate the water. This process also results in increased humidity. An indirect system passes the supply air through a heat exchanger so that the humidity stays out of the air stream. This can produce total energy savings of 4% in a hot dry climate, and 1-2% in other climates.
The potential for evaporative cooling is measured by the difference in dry bulb temperature and wet bulb temperatures. While dry climates have greater potential for evaporative cooling they typically do not have abundant water resources. Energy saving are achieved because minimal mechanical energy is required other than the fan energy. The trade off between energy savings and increased water consumption should be considered in the context of the local ecology and utility prices. Moreover, the offsite energy savings are limited because of the energy intense processes associated with water treatment and transportation.
An absorption chiller uses a heat source to generating cooling. While this process is less efficient than that of a conventional vapor-compression chiller, savings can still be realized where solar thermal or waste heat is available. Where steam is available, a double effect cycle can increase the efficiency by 50% over single effect.
Absorption chillers do not consume electricity or CFC or HCFC refrigerants, however commonly have lower reliability than other chillers  2021.
Hotels located in hot dry climates may consider using evaporative coolers. Controls should be used so as not to exceed comfortable and safe humidity levels. An indirect system should be used where humidification is not desired.
A hotel site that is appropriately situated for solar thermal, or that will generate significant waste heat, should consider an indirect fired single effect absorption chiller to utilize this thermal energy. This is a HVAC good system to use when fuel cells or a CHP plant are in the design.
These systems should only be considered when an extensive refurbishment or replacement of the existing cooling plant is necessary.
A refrigerant is a fluid used in a machine that is designed to pump heat from a lower temperature heat source to a higher temperature heat sink. CFCs, HCFCs, HFCs, ammonia, water, and CO2 are different types of refrigerants.
CFCs in particular are known to deplete the ozone layer. As a result, the use of CFCs has been phased out in most developed countries since the signing of the Montreal Protocol in 1989, while developing countries have until 2010 to eliminate their use. Additionally, HCFCs cause damage to the ozone layer and are also being phased out.
The Ozone Depletion Potential (ODP) measures the effect of the selected refrigerant on the ozone layer. The Global Warming Potential (GWP) measures the effect of the refrigerant on global warming. ODP and GWP calculations ensure that the most 'environmentally friendly' refrigerant is used  23.
When selecting refrigerants for HVAC and cooling equipment, the ozone depletion potential and the global warming potential should be researched and calculated. The lifetime of the equipment, refrigerant charge, and amount of refrigerant are all values that must be considered when selecting refrigerants.
Existing hotels that use CFCs and HCFCs in HVAC and cooling equipment should begin a phase-out program and replace existing refrigerants (if possible) or equipment. Since production of these refrigerants is or will be discontinued, the availability will decrease over time.
When the outdoor air temperature is at or below the supply air temperature, an airside economizer mode on an air handler achieves free cooling by using more outdoor air instead of cooling the return air. This can also be done when the outdoor air is greater than the supply air temperature, but less than the return air temperature. An enthalpy economizer mode has additional control to compare enthalpy rather than temperature to ensure that outdoor air is only used when the enthalpy is lower than the return air enthalpy.
Economizer mode is required by ASHRAE 90.1-2004 for systems of certain sizes, dependent on climate zone. Different controls for economizer mode are also recommended based on climate zone.
While airside economizers are more common and offer a large savings, economizers can also be used in water systems when it is cold outside and cooling is still required inside. This is typical of interior spaces with high loads, such as conference rooms and meeting spaces in hotels. The economizer mode consists of running the cooling tower condenser loop through a heat exchanger rather than operating the chiller.
Economizers should be considered in relation to on site-specific factors such as climate, and various other HVAC related credits. Economizer cycles are most beneficial in areas with cooler or temperate climates, and may not be appropriate in high humidity regions or in extreme climates. Though they carry an additional capital cost, the energy savings can produce fairly short payback periods.
Retrofitting to existing systems may be suitable where climate is appropriate and thermal loads are sufficiency high. This is not applicable to systems that have room air conditioners only.
Ventilation heat recovery uses an enthalpy wheel, plate heat exchanger, or run around coils to capture heat from exhaust air to preheat or precool the outside air. In cooling mode the heat flow is reversed and the outside air is precooled by the exhaust air. Plate heat exchangers, heat pipes, or run around recovery loops recover sensible energy only. Enthalpy wheels recover sensible and latent energy, meaning that the humidity of the ventilation air can be affected too if necessary. The benefit of ventilation heat recovery increases with increasing outdoor ventilation rates. Therefore, ventilation heat recovery is a good technology to temper the increased energy cost of improving indoor air quality. The downside of heat recovery in ventilation systems is that the heat exchangers require significant space, have a higher capital cost than a traditional air handling unit, and add to the system pressure drop.
There are also other opportunities to recover heat from HVAC systems. Heat sources occur when a large amount of energy is thrown away in a system, such as return air, exhaust air, chillers and compressors. Heat sinks are opportunities to recover waste heat, and include supply air, ventilation air, process water, and domestic hot water. Heat is transferred from a source to a sink via a heat exchanger, thus saving the energy that would have been discarded from the source system and reducing the energy required by the sink system. Factors such as the load profile, and reliability and locations of the source and sink will affect the system performance  25.
The most likely opportunity for heat recovery in a hotel environment is ventilation heat recovery between outside and exhaust air. Industry figures state payback can be as short as 2 years. Hotels with high process loads or large exhaust amounts could use run around heat recovery coils or heat exchangers.
Providing suitable heat sinks and sources exist, the cost of incorporating a heat recovery system into an existing hotel may be justified by the energy savings. If a central outside air unit is being installed as a retrofit, ventilation heat recovery should be explored.
Enhanced HVAC guest room controls & CO2 monitoring
Better control of guest room temperature, humidity, and air quality can improve guest comfort. Usually only temperature is monitored and controlled. Better overall room air quality can be achieved by also monitoring humidity and carbon dioxide. Additionally, incorporating room controls system into the building management system (BMS) will also allow for hotel personnel to better manage guest rooms.
Use of a humidistat to measure humidity ensures that the levels never increase above an uncomfortable or unhealthy level. If humidity increases above a level of approximately 60% RH, the room air conditioning unit runs in cooling mode even if temperature is satisfied. This dehumidifies the air to bring it back down to normal levels, and the unit then reheats the air if the temperature drops too low.
CO2 monitoring can improve general indoor environmental quality in hotels, providing a higher level of health and comfort to guests and workers. Headaches, drowsiness and low productivity have all been correlated with high CO2 concentrations. Installing a CO2 monitoring system would allow outdoor air ventilation rates to vary depending on the number of occupants and their activity level.
To properly install these controls, a building management system (BMS) should be installed. The BMS would monitor all three sensors and ensure that the system operates properly to maximize comfort and save energy.
The efficiency of guest room controls is maximized by linking it to a building management system. Dampers and control points would need to be installed to achieve maximum potential.
HVAC controls are most easily implemented early in the design phase and may be difficult to retrofit to existing hotels.
Motor energy efficiency
Electric motors are used extensively in buildings and in particular in heating, ventilation and air conditioning systems. Motors are used to pump water in heating, cooling and domestic water systems and also to run fans in ventilation systems. NEMA set up a premium efficiency motor program in 2001. This program set standards for motors to meet in terms of their construction with the intention to minimize losses and hence increase efficiency. This resulted in motors with efficiencies up to 96% (2% to 8% better than standard motors).
Even small increases in efficiency can result in dramatic savings in energy and running cost, particularly for larger horsepower motors. For example, an improvement of 5% in the efficiency of a single 20 HP motor, operating for 8,000 hours per year, will result in saving of $260 in energy costs and 4 metric tons of CO2 emissions per year.
Motor efficiency can be further improved through the use of variable frequency drives (VFDs), which control the speed of a motor by varying the frequency of the AC supply. VFDs allow the flow rate in systems to decrease at part load. Since power consumption varies with the cube of flow rate, significant energy savings can be realized.
VFDs can be placed on most HVAC systems, as long as the systems are designed for variable flow. Since most systems rarely operate at full load, energy savings can be significant. Fans, pumps, and motors all can be fitted with a VFD  .
NEMA Premium motors typically carry an additional cost premium of up to 15%. This is considered cost effective when annual operation exceeds 2,000 hours, with a payback period of less than 5 years. Installing VFDs shows a significant savings immediately since a large portion of energy used in a building is for the HVAC systems.
It is not cost effective to replace all existing standard efficiency motors with Premium motors. However, replacement should be considered where older motors are running with particularly low efficiency or when repair or rewinding is necessary. Cost analyses should be done to determine the feasibility of installing VFDs on existing equipment. Also, the systems should be inspected to see if valves will need to be replaced in order for the VFD to operate properly.
Electrical consumption is one of the most costly aspects of hotel management from both a financial and environmental standpoint. With careful design, it is possible to minimize this load without diminishing the well being of guests and staff. This can be achieved through the use of:
Efficient lighting design
Energy saving products
On-site power generation
Effective energy controls and management
Coordinated electrical design should be pursued for hotels. Use of energy efficient products, lighting control systems, day-lighting, and renewable energy can all contribute. The building should be commissioned and on-site power generation should be researched to see if it is applicable to the project. Good electrical and lighting practices can save money, provide a more comfortable environment for guests, and reduce carbon emissions.
Best management practices
The energy efficiency of a building is dependant not only on the various mechanical and electrical systems that are in place, but how these systems are used by the occupants. Improving building systems operations is often a fast, low-cost way to significantly reduce energy consumption. Development of a sequence of operations and building operating plan forces hotel operators to describe and understand how various systems work and interact. Combined with a preventative maintenance program, this ensures than systems are operating the way they were designed to and allows potential problems and inefficiencies to be identified and corrected.
A sequence of operations and building operating plan are developed during construction documentation, and should be stored and understood by hotel management. The preventative maintenance program should be adopted as soon as the hotel is occupied.
Metering equipment and other consumption measurement procedures should be used to quantify system performance and energy. Hotels shall be required to keep accurate documented records and measurements of all energy consumption. The metering procedures also enable verification of the performance of credited actions over time to ensure savings are maintained. Results can be used to tune building systems for improved continuous performance and to assist in energy use evaluation for future hotels. Sites can be compared against each other to identify the effectiveness of credited actions implemented at one hotel versus another. Sub-metering can be installed for lighting, boilers, steam, gas, power, water piping and other utilities.
The hotel owner needs to decide what to do with the metering data before installation. A meter at the source level (a meter for the entire building from the utility) should always be installed. Feedback on energy and water usage should be provided through the hotel's ecological program. Meters should be installed for a lifetime above 20 years.
In existing hotels, identifying and targeting areas of high consumption and greatest potential for energy savings will reduce costs of a new metering system. Existing meters shall be regularly checked to ensure calibration within manufacturer's tolerances and intervals. This data shall be entered into an online monitoring and calculation tool via the group dedicated software which shall produce outputs that allow the hotel to assess its performance against previous years and compare performance with other hotels. Hotels shall be required to keep accurate documented records and measurements of all energy consumption for a minimum of five years for verification of past online entries.
All installed meters must be calibrated to manufacturer's requirements and be included as part of a documented equipment maintenance schedule. Other fuel measurement procedures such as dipstick measurement from fuel oil tanks should have a brief method statement describing how values (e.g. volumes) are calculated and the proposed program of intervals between readings  .
Energy performance benchmarking
Hotel energy management is about tracking energy performance and identifying opportunities for improvement. This relates not only to past performance but also how current performance compares with other buildings of a similar type. A concise and standardized system of energy monitoring and performance evaluation is important to allow this to happen.
Many of the systems designed into a project offer a significant return on investment; however, this can only be ensured if the systems are being monitored for acceptable performance. Environmental targets should be clearly detailed in an Environmental Management Plan. Corrective actions should be developed for staff to follow when targets or benchmarks are not met.
Projects should be metered to allow for isolation of system performance. Facilities managers should develop monitoring plans that include performance comparisons against projected savings and/or similar building type databases. When goals are not met, measurable short and long term targets for improvement should be established.
There are many areas with environmental standards well below others. If developing projects in one of these areas managers should work with the group and the local community to improve environmental standards in the local area.
Set performance benchmarks during design using expectations from energy models or building databases. This may be done by using energy models to calculate predicted energy performance and then comparing this with a baseline building's energy performance. The energy improvement of the proposed building against the baseline building can be used to calculate achievement of minimum performance targets.
Upon completion and occupancy, monitoring plans and enrolment in the group dedicated software's online system will help determine if projects are meeting these goals. Designing building management systems or system sub-metering will assist data collection.
Metered and measured energy consumption data shall be entered into the software, which benchmarks this data against hotels across the group portfolio and calculates whether the hotel meets the group's minimum performance requirements. It also allows managers to track performance against a number of other parameters including historical trends and energy consumed per guest night.
Hotels that do not meet the minimum requirements may consider implementing other action groups to improve performance. These may include capital improvements outlined in the Energy, Building Envelope or Mechanical sections, or operational improvements found in the Operations & Processes section.
Building energy system commissioning
The commissioning process is a series of steps that occur during both the design and construction life of a building and even following occupancy. The aim of this process is to ensure firstly that buildings are designed in a way that enables them to be commissionable and meet the building owner's requirements for the building. Additionally, commissioning ensures that a buildings energy consuming systems are purchased, installed and are operating as the designer intended them to. The commissioning process can have a significant impact on the whole life energy of a building. The embodied energy associated with constructing a building are small when compared with the operational energy and embodied energy required to replace, upgrade and modify interiors of buildings throughout their life. This is particularly relevant to hotel resorts because they undergo re-fits approximately every eight years, due to continued wear on the building interiors  29.
Implementing commissioning steps into the early stages of a hotel life can identify and prevent energy waste over the remainder of its life.
Consideration should be given to the timing of commissioning in construction. Commissioning realizes greatest savings and catches the most system deficiencies when the process is started early. NOTE: The LEED rating system has specific requirements for commissioning which are time-sensitive starting in mid design.
Retro-commissioning can provide immense savings for existing facilities whether construction, renovations or upgrades are scheduled. Once retro-commissioning has been complete, the resulting documentation can be used annually to re-check systems performance and continued savings and efficient operation.
Building management system
Building Management Systems (BMSs) are commonly employed in modern hotels to allow centralized monitoring and control of the building's mechanical and electrical systems. Sensors and actuators are incorporated into the ventilation, lighting, power, heating, cooling, hot water, security and fire systems and linked to a centralized computer. From there, software programs are used to monitor and control the systems according to the desired parameters. This Direct Digital Control (DDC) technology enables building management systems to co-operate on programmed schedules and to use weather conditions to predicatively maintain desired thermal comfort, lighting, and services (fire, security, etc) while minimizing energy consumption. DDC can alert staff to faulty equipment or out-of-tolerance conditions with the use of system alarms allowing maintenance work to be carried out before any serious guest disruption or remedial costs occur. Alternatively, stand alone controllers have limited interconnectivity and control flexibility  31.
A system can be installed in hotels to recognize when guests leave their room and save energy during these times. A central monitoring system can be installed as stand alone on a room by room basis, but are more effective, particularly for larger hotels, when they report back to a central location. This can enable staff to monitor the status of rooms including occupancy, energy consumption, maintenance issues (such as faulty equipment), security issues and can be used to generate trends of room usage statistics that can be useful in future planning for housekeeping, maintenance and other staff. Automated adjustments could be made for heating and cooling when guests check in and out  33.
Wireless BMS systems are available for installation on selective equipment at existing facilities. These systems are expensive to install but flexible.