Going behind the scenes…
With Denis Sorin, President of Hotel Operations, Dur Hospitality

Denis Sorin, President of Hotel Operations, Dur Hospitality

What is the position of Dur Hospitality on the issue of Indoor Environmental Quality (IEQ)? How does it ensure a good and comfortable indoor environment for its guests?

Our brands are working hard on IEQ, particularly in the area of soundproofing. We are keen on ensuring that our guests are not disturbed by guests next door or by someone working, or even shouting in the corridor. For instance, in developing our standards for Makarem, which is one of our brands, we paid close attention to the DB (decibel) levels in certain areas, like at the bed’s headboard and the bathroom near the door, because we understand that when you sleep or when you are in your bed, reading, you don’t want to be disturbed by what’s going on next door.

We also pay attention to air conditioning. If you look at the air conditioning systems in most hotels today, you’ll notice that you need to be a scientist to understand how to make them work.  Sometimes, you don’t know how to switch the unit off or how to change the temperature. We are looking at the people and the companies we are working with to ensure that the systems are simple to operate and that they work.

So we are working on every aspect of the indoor environment and the guest experience to make sure that guests enjoy themselves. For me, a good hotel is one that makes you forget that you are staying at a hotel. It should not be what complicates your life but what simplifies it.

You mentioned standards earlier. Could you elaborate on the kind of standards that you are using or adopting?

Depending on where the room is located in the hotel, the conditions change, and BMS allows us to understand the differences between rooms and be able to adapt solutions to the needs of each room

We are reviewing different standards. When you’re developing a new brand or adapting a brand to a new market or a new market request, you have to understand exactly what guests need. We have been conducting surveys to understand what the guests of today expect and what the guests of tomorrow will expect to find in their rooms. For instance, until recently, the standards of hotel brands were primarily concerned about the colour of the walls, the type of marble on the floor and other similar elements. Of course, those are important. They set you apart from other brands which may be offering the same quality of service. But we have to go further. Guests are expecting a lot more today, particularly in terms of technology. And technology is not only about having proper Wi-Fi connection, but it’s also about, as I’ve mentioned, simplifying the guest’s stay. For instance, while guests do want to be able to connect to Wi-Fi easily, they also need to be able to – again, easily – address their cooling requirements and get their preferred water temperature; some like hot water in the shower, while some like cold water.

Image credit: Shutterstock

Since we’re on the topic of technology, could you share with us how you utilise building management systems to improve operations in your hotels? How important is BMS in your hotels?

It’s very important. There are two different ways of implementing a building management system. There’s the basic way, which is just checking the temperature and basic elements like that. The other way is going into details and checking, for instance, every  single air vent in the room, both when the guest is inside and when the guest is not in the room, in order to fully understand what’s going on in the room. This is because, depending on where the room is located in the hotel, the conditions change, and BMS allows us to understand the differences between rooms and be able to adapt solutions to the needs of each room.

How do you keep your facilities maintained? Do you have an in-house facilities management team?

Yes, we do. We are working with professionals with experience gained from working for different [hotel] chains. When you have varied experience, you are exposed to different ideas, and you are able to put together all those ideas and come up with better ones.

Our team is very much dedicated to understanding and satisfying the needs of our guests. They spend their day going through our hotels; seeing where we are weak, where we are strong, what we can do to be better and identifying ways we can save money, because there’s a high cost related to air conditioning and there’s a high cost related to water consumption.

During the peak of summer, we experience high condensing pressures in chillers, resulting in reduced efficiency

One project we are working on in our properties is recycling water by using grey water in the toilets. Why do we use clean, drinkable water to fill the toilet tank when we have grey water? Air conditioning systems produce wastewater through condensation. We’ve found a system that allows us to reuse the water of the air conditioning system in our toilet tank. It’s a way to provide the service that guests want, while behind the scenes, we save a lot of money.

The guest should not be made aware of whatever problems or issues we may have, including efforts to reduce energy consumption. Like I said, when you go to a hotel as a guest, you have our own life.  The operations of the hotel should not be your problem.

What we do is look at the way things are done. We look at how hotels are organised and operated, because when you build hotels from the ground, it’s quite easy to be energy efficient, to be water efficient. It’s much more complicated when you are working on an existing building. We’ve been surveying all the older buildings that we have, and evaluating how we can make them more efficient. And we’ve actually found a lot of things that can be done – simple things like low compared to the savings that you’ll be making.

Getting technical…
With Aamir Riaz, Corporate Director of Maintenance, Dur Hospitality

Aamir Riaz, Corporate Director of Maintenance, Dur Hospitality

That kind of cooling systems does Dur Hospitality use in its hotels? And what were the factors taken into account when the selections were made?

We have both air-cooled and water-cooled chiller systems in Dur properties.

Energy conservation and upfront costs are always critical discussions in any project when it comes to system selection. In some projects, initial costs can outweigh lifecycle and operating costs. And initial costs of chillers can vary, since there are multiple factors involved other than the size.

In general, scroll chillers are the most expensive type of chillers. Centrifugal chillers, meanwhile, are the most cost-effective option, but they are not available in all tonnages. While screw and centrifugal compressors are both available options, based on the capacity, screw compressors are typically 10% to 15% more expensive. Similarly, air-cooled chillers tend to be more expensive than same-sized water-cooled chillers – at least if we strictly compare only the initial costs.

When evaluating the total installed cost of an air-cooled system against that of a water-cooled system, however, the investment required for the latter is bigger because of all the components it requires to be operational. An air-cooled system only requires chillers and chilled-water pumps, whereas, a water-cooled system requires chillers, chilled-water pumps, condenser water pumps and cooling towers to be fully functional and energy efficient.

The area, building design and available resources are also factored into our selection criteria. System operation is linked to groundwork for selection; hence, selecting the right product will help minimise future maintenance troubles.

Having already covered the issue of costs, could you assess the performance of the different cooling systems you’re using? How are they in terms of energy efficiency? How about in maintaining good Indoor Air Quality and thermal comfort?

In few Dur properties, some HVAC systems were old hat – they were obsolete and not environment friendly

Based on studies and experience, water-cooled systems are more energy efficient. They not only reduce operating costs and provide clear financial benefits but also help protect building owners and operators from uncertainties in electricity pricing. When selecting a cooling system, make sure to conduct an energy analysis to see which system is best for your application.

Air-cooled chillers operate on the concept of using air to reject the building’s heat, which approaches the outdoor ambient dry-bulb temperature. Consequently, air-cooled chillers must raise the refrigerant temperature and pressure to a higher condition and, therefore, require more energy than water-cooled chillers to provide the same amount of cooling. Despite this, air-cooled chillers offer the advantage of a packaged system with a single source of responsibility. Design and installation time is also reduced due to less equipment being involved – there is no requirement for cooling towers and associated freezing issues; consumption of make-up water and chemical treatment or condenser water pumps. Air-cooled chillers use scroll compressors up to 200 TR and use screw compressors above 200 TR of capacity.

Water-cooled chillers, meanwhile, operate by using water to reject the building’s heat, which approaches the outdoor ambient wet-bulb temperature. Because wet-bulb is typically lower than dry-bulb temperature, the condensing temperature is also lower, meaning less work is required from the compressor to raise the refrigerant temperature and pressure.

Image credit: Shutterstock

Although the water-cooled system’s energy requirement may be less than that of a comparable air-cooled chiller, one must still evaluate all the costs of the chiller system, including – as I’ve mentioned – the costs of components like cooling towers and condenser water pumps. The smallest water-cooled chillers (up to 200 TR) begin with multiple scroll compressors; those from 200 to 500 TR use screw compressors; and those above 500 TR mainly use centrifugal compressors. Water-cooled chillers typically last much longer than air-cooled chillers due to the location of the chiller (inside the building) and lower operating pressures owing to the use of water as a condensing fluid.

With regard to maintaining good Indoor Air Quality and thermal comfort, what’s really important is adopting a good preventive maintenance programme, as is following manufacturer-specified operating guidelines.

What kind of maintenance does your department carry out to make sure Dur Hospitality’s HVAC systems perform at an optimum level? How often do you carry out inspections and what do you check when performing said inspections?

Checking refrigerant temperature and pressure and cleaning electrical components and condensers are the key elements to achieving optimum system performance. They are scheduled – based on running hours – daily, weekly, bi-weekly, monthly, quarterly, bi-annually and annually.

I strongly recommend system periodic maintenance by authorised service dealers. Of course, daily routine maintenance, which can be done by an in-house team, is essential.

What are the common problems and challenges you encounter when maintaining HVAC systems in hotels?

During the peak of summer, we experience high condensing pressures in chillers, resulting in reduced efficiency. Also during summer, consumption of make-up water tends to be excessive, and there’s a need for frequent servicing   of condensing coils due to sand and dust storms.

I understand that Dur Hospitality has been working on replacing old air conditioning equipment. What systems have you replaced and what replacements have you installed?

In few Dur properties, some HVAC systems were old hat – they were obsolete and not environment friendly, that is, they ran on Freon R11 and R22. And because they were not performing up to the required level, we lost on our targeted revenue. So, considering the environment and the thermal comfort of our guests, we invested SAR 8 million on HVAC to replace old systems with the newest and latest chillers, which are energy efficient and environment friendly.

We floated and diversified the tender to arrange site surveys for vendors and gather expert opinion, as a way of preparing for groundwork and implementation.

As I mentioned earlier, the area, building design and available resources are factored into our selection criteria; hence, we selected a complete package of air-cooled chillers with the latest technology.

I am confident that upon the completion of the project, the new systems will cover the thermal comfort requirements of our buildings and will generate a handsome revenue.