The state of the environment is top of most people’s concerns nowadays, and “greening” policies are not only a fashionable movement but a necessity to ensure our planet’s survival. A new development in Umhlanga – the Gateway Hotel – is being constructed in line with the Green Building Council of South Africa’s guidelines and we interviewed Three Cities Group Engineer, Murray Burger to get the (green) scoop!
So what does a Group Engineer actually do?
I consult with all the properties within the Three Cities portfolio to ensure that they all conform to the most appropriate engineering and maintenance practices. I also work to instil a sense of “Green/Energy” understanding throughout all properties while ensuring all systems are as efficient as possible. I also advocate “Green/Energy” initiatives from a property development phase.
What does “Green” actually mean – in terms of designing a hotel?
“Green” designs must incorporate sustainable environmental policies from project inception to end-user operations, ensuring that all aspects of the development, construction and operating processes result in the lowest overall environmental impact.
Do you think the Gateway Hotel meets these requirements?
Yes! This property is undoubtedly an achievement of sustainable development.
I must convey my sincere gratitude to the consultants and contractors responsible for producing such an awe-inspiring building.
Three Cities is indeed fortunate to have a landmark of such prestige within the company portfolio.
What aspects of the new Gateway Hotel are actually “green” or “energy efficient”?
There are many parts of the Gateway Hotel which are “green” and energy-efficient.
Firstly, during the design, construction and development of the Hotel, both the developer and contractor took cognisance of the GBCSA (Green Building Council of South Africa) guidelines ensuring that the following development/construction aspects were accounted for:
• Waste Management – Reuse and Recycle Building Materials
• Topsoil Re-use
• Local Sourcing – Local suppliers of materials
• Environmental Management – Reduce impact of building practices on the environment.
Secondly, the architects involved with the development had a number of innovative ideas to make the Hotel as “green” as possible.
For example, to increase the amount of natural light, atrium light wells were installed to project light deep into the building.
Even the materials selected in the building process contribute to making the Hotel more environmentally friendly.
Extensive use of concrete throughout the building was used not only to satisfy the desired means of construction, but also to act as heat sinks or cold beams. There was also an effort to limit the use of kiln-fired bricks for internal service level walls, duct shafts and room divisions.
Instead, all other room divisions have been installed using a “green” accredited, fire-rated, drywall construction, with “green” waterproof boards in wet areas.
Despite the different materials used for room divisions, all installations are in accordance with accepted acoustic decibel ratings.
To lower energy consumption even further, a vermiculite screed (cement and polystyrene mixture) was added to the rooftop which created a further heat barrier. This means a cooler building with less air-conditioning use!
So how does a hotel generate hot water in an environmentally-friendly way?
Heat Pump technology has been prevalent in the hospitality industry for some time.
In fact Three Cities introduced heat pump technology into one of their hotels some 15 years ago, already aware of the energy efficient benefits associated with heat pump technology.
The Gateway Hotel incorporates two high-efficiency heat pumps, ensuring every drop of water is heated to temperature using as little electrical energy as possible.
Every effort has been made to maximise the flexibility of this hot water generation system including independent control systems for each heat pump (meaning output temperatures can be adjusted according to desired operating parameters), as well as bi-linked independent compressors within each heat pump (ensuring a single heat pump may perform at 50% capacity should a single compressor unit fail at any stage).
Another valuable output of this heat pump installation is the integration of the chilled (+-15° C) exhaust air into the air-conditioning system.
The Gateway Hotel heat pump installation preconditions the kitchen fresh-air system with this chilled exhaust air which reduces the electrical demands that would normally be required by the central air-conditioning plant to chill the kitchen supply air.
Apart from the highly efficient heat pumps, a water preheating facility is also available. Through the use of a plate-type heat exchanger, temperate air-conditioning condensate heat energy is exchanged with the colder municipal incoming water. In effect, this preheats the colder water in such a way that a lower electrical input is required to heat the water to the desired temperature.
The hot water storage and reticulation facilities have also been designed as efficiently as possible. Well insulated storage and reticulation installations ensure that heat energy losses are kept to an absolute minimum. “Dead-leg” pipe-work runs are as short as possible ensuring that all water losses are minimised (including heat energy losses).
The installation of “low-flow” water outlets ensures continued guest satisfaction whilst reducing both water usage and associated water heating energy usage.
That sounds very impressive! But what about waste management?
The installation of kitchen floor drains connected into an easily accessible, common grease trap ensures that only suitable waste is processed by the council sewage works.
An easily accessible service level section of the hotel will host a dedicated waste management program. Waste sorting and recycling programs will be implemented from this area ensuring waste disposal programs are fully supported.
All equipment and amenity provisions will be sourced and disposed of in accordance with accepted environmentally friendly practices.
Heating, Ventilation and Air-Conditioning (HVAC) usually account for a larger portion of energy consumption. How does the Gateway Hotel solve this problem?
This is true. In fact the HVAC components alone will contribute to approximately 40% of the total electrical load at the Gateway Hotel. Due to this energy usage, all HVAC systems have been designed with maximum efficiency in mind.
For example, the window-glazing used on the building is a thermal performance glass with an acceptable light transmission of 47%. This provides sufficient natural lighting in areas. The use of performance glass ensures that air-conditioning loads are maintained as low as possible, since direct heat energy transmission through the glass is controlled.
Also, the use of external shading devices is considerably more efficient than the use of internal shading devices. The eye-catching “leafy” screen surrounding the Gateway Hotel uses this very principle. This iconic screen acts as a solar shield on the dominant northern facade of the building.
This means that heat energy is absorbed outside the building, which reduces the solar radiation load inside the building.
Another way to reduce HVAC consumption dramatically is to position the building in a certain way. For example, the Gateway Hotel is oriented on a north-east/south-east axis with the dominant facades facing the north-west and south-east.
It is interesting to note that if the Hotel was instead positioned on a north-west/south-east axis, the annual energy consumption would have increased by some 34 000 kWh’s! This is the equivalent energy consumed by a 50Watt globe burning non-stop for 77 years!
Control units are also installed within each area or room to ensure air-conditioning units only operate when cooling is required.
An important point to note is that a building management system (BMS) is installed within the Gateway Hotel infrastructure.
From an HVAC perspective this system facilitates both remote monitoring and remote control (management can log onto the system from anywhere in the world) – ensuring units are switched-off when not required.
The ability to control these facilities remotely adds to the flexibility required for an effective energy management program.
Another feature of the Hotel: fresh air is pre-conditioned through two centrally chilled water-air handling units and thereafter supplied directly into the rooms.
Fresh air will continuously be blended into rooms to keep the rooms “fresh”, even if the air conditioning units are switched off.
The burning of fossil fuels for power generation has resulted in global warming. To reduce emissions of CO², a reduction in electrical energy use is required. How does the Gateway Hotel ensure that minimal electrical energy is used?
Light Emitting Diode (LED) down-lighters are used for the general lighting of the guest rooms. The life expectancy of 15 000 hours, coupled with a power consumption of as low as 5 Watts per globe makes LED lighting a favoured option!
Other LED benefits include a marked reduction in the overall heat load of the room, and lower electrical energy needed to achieve the desired light levels. While energy-efficient lighting is vital in ensuring reduced electrical loads, the installed lighting systems cannot compromise on safe, appropriate lighting levels. As such, the Gateway Hotel lighting systems are designed to cater for all requirements within reason.
Control units are also installed within each room to ensure lighting or electrical loads only operate when required. This “key-card” facility controls the electrical loads associated with guest rooms during occupancy fluctuations.
A great innovation; the OTIS lifts installed within the Hotel make use of re-generation drive systems.
In essence this means that the energy used in the stopping or braking of the lifts is converted back into electrical energy to be used elsewhere. Impressive isn’t it?
All of this does sound very impressive! So how does it help the environment?
The benefits are endless. The efficient integration of environmentally sustainable design, construction and operating principles will minimise the negative effects of this development on the environment.
By reducing the energy requirements and subsequent consumption of any site, power generation facilities can reduce carbon emissions.
Also, the use of approved building materials and approved building techniques has ensured the longevity of the building while also reducing any environmental impacts normally associated with construction processes.
In your opinion, why is “greening” hotels important?
“Greening” all new and existing developments is vital in ensuring a sustainable future.
To cater for the world’s expanding population, more and more developments are being built. Unless environmentally conscious systems are integrated into the development process it is only a matter of time before all natural resources are exhausted. People read and hear about these environmental initiatives on a daily basis yet very few people actually make any positive changes.
People continue to be labelled as “green-freaks” and in some instances this may actually be true, but the fact remains: the planet cannot sustain humanity given the current demands placed on it and unless humanity’s impact is reduced immediately the planet will lose the last remaining resources and effectively shutdown. This may appear to be a long-term forecast but unfortunately the damage from years of neglect and the continuous destruction of our planet will force our extinction. We need to focus on effective changes and make them on a daily basis!
Do “greening” designs or policies detract from the traditional luxuries of a hotel?
In a number of instances the environmentally sustainable and energy efficient designs of the “Gateway Hotel” actually add to the luxuries of the hotel.
Natural lighting techniques, efficient cooling and heating systems as well as creative architectural design intent ensure that every guest is accommodated in a world class environment. The “traditional” luxuries have been upgraded in accordance with environmentally sustainable practices rendering it a truly luxurious experience.
What do you like most about your job?
My job is unparalleled! Working with new technologies, on various sites, on a daily basis makes me extremely fortunate. Energy management is vital in ensuring efficient operations for “Three Cities” and working from inception to completion on this project in particular has been phenomenal.
Project coordination, budgeting and design confirmation are all associated with a project of this nature and experiencing these project aspects first hand is invaluable.
Is there anything else you would like to add?
Although I have made mention of a number of energy efficient and environmentally sustainable solutions, the benefits of these systems cannot be contained in a document of this nature.
The Gateway Hotel is a unique building, destined to set a new benchmark of success for the Three Cities Group. The effective implementation of environmentally sustainable designs will go a long way in ensuring the impact of this development contributes to even more efficient developments in the future!