Roundtable: Radiant Ceiling Cooling
A clutch of industry experts debate the latest cooling technology
MEP Middle East brought together six industry experts to meet Volker Ruehle, Middle East consultant for SGL Group The Carbon Company, and discuss his firm’s Ecophit radiant ceiling system.
The system is based on graphite ceiling panels that are chilled (or heated depending on the demands) by embedded copper meander tubes. Ecophit has already been installed as a heating/cooling system in some European projects, such as the Deutsche Bank headquarters in Frankfurt, and has also been applied as a cooling system on an IT centre in Bangalore, India.
However, SGL was keen to prove its value in the sweltering climate of the GCC and established a testing facility in Dubai. As Ruehle explained to the six industry experts, the results were just what the company had hoped for.
“We did a test-bed with Red Engineering and ALEMCO in Marina Plaza Tower. There were two rooms similar in size and equipment. The left room was equipped with traditional fan coil units (FCUs), at traditional design stage, and had traditional air supply.
"The right-hand side room had a combination of fan coil units and our active Ecophit ceiling cooling. The left side had air supply of 40 litres per second per square metre, that included latent and sensible load.
"On the other side we provided the whole cooling load, meaning sensible load, with cooling panels, and the fan coil unit supplied only 8 litres per second per square metres of fresh air for dehumidification and artificial fresh air supply. Our main aim was to reduce the total air flow by providing a certain amount of cooling capacity.
“We were able to supply 85 to 95 watts per square metre depending on the outside condition,” Ruehle continued.
“Red Engineering did a report on the research for all of the figures for 14 months and the conclusion is that we can save approximately 40% of the energy. We have to consider different inputs because of humidity; if you put people in the room the latent load will be much higher and the savings are much less.
"But this is not our aim; our target is to provide a better comfort because cooling and heating technology with radiation is much better than air. Noise and draft are things that have to be considered. This technology with a smart central air cooling system should be a perfect solution for this region.”
With this presentation of the system and its proven benefits made, Ruehle invited the assembled experts to discuss what they had heard and raise any concerns or queries that they had regarding its efficacy.
Professor Abu Hijleh: “The main reason I find this interesting is the decoupling of the cooling and the ventilation requirements because I think that is the biggest issue we have here.
"We have big problems with improper indoor air quality; you try to increase that when you’re increasing your cooling load like crazy. The fact that you can control each one individually is a very big advantage. The issue you have to be careful of is leakages.
"Buildings here are notorious for being leaky. Although in Abu Dhabi you are required to do an air pressure test for new buildings, air leakage is still there in most older buildings.
"The sealants they use, with the temperature here, they tend to crack after a while. This might come back to haunt you a couple of years down the line.
"When the building starts to leak, all of a sudden people will start to complain about your system having a problem, and the problem is actually the facade. This might be something you need to educate clients, consultants, contractors, and users – or maybe even provide free of charge inspections just to ensure that your system doesn’t take the blame for something it’s not responsible for.”
Alistair Davis: “It seems like an interesting product. There are some definite applications for it. As a consultant, some information on some of the other projects that you’ve done would be useful.
For example, before and after energy data from the Deutsche Bank installation. You gave figures of 50 to 60% reduction in terms of energy for both heating and cooling at Deutsche Bank – more information like that would be great.
"In the end, if we [consultants] want to propose anything like this we want to see what the advantages are, what previous installations you’ve done etc., so at least we can go forward and have confidence that it has been used and has been used successfully.
"That’s why it’s good that you’ve got a big installation like Deutsche Bank because they are a very well-known reputable company. Banks are risk averse and don’t want their business going down. I guess you’ve got it above one of their main trading floors, so one of the big things is that they don’t want any water in that space. It’s a great company to have.”
Professor Abu-Hijleh: “Talking from an academic energy point of view, I can see several advantages for this system. The higher chilled water temperature means more efficiency, lower equipment requirements, high efficiency on chillers, and the separation of cooling load from ventilation load is extremely important.
"The potential for savings is huge. The space saving issue is also very important. Many buildings have restrictions on total heights so you can fit more floors within the height. This will mean more leasable area and more money for the owner. Even if not, the structure will be lighter meaning that there will be less foundations and you’ll save money on that as well.
"It’s good that you’ve followed standard protocol in terms of testing, but people will always be sceptical. It has great potential but needs work.
Jeán van Loggerenberg: "From a consultant’s perspective, from a PI (professional indemnity) and liability point of view, we have to careful when adopting things in this region. But it has huge attractions such as the energy savings.
"Some of the big issues here are air distribution, drafts and noise, and its handling of these could help it a lot. Thinking about applications, you have to be careful about infiltration in buildings, but maybe big buildings like airport terminals or shopping centres where you’ve got a lot of over-pressure, which limits the amount of infiltration, maybe you should look at this application. But it is very interesting."
Professor Abu-Hijleh: "That would be a very important application because usually when you are over pressurising you are losing a lot of the cold air. Because of the radiation you’re not losing it. The cooling effect remains there; it does not go out with pressurised air."
Mohamed Elmasry: "I think from a trading point of view the most important factor is the cost of this ceiling. If you want to penetrate any market you need to beat your competitors, even with a new innovation like this. You need to have a certain limit for the cost to convince the clients to invest in the product. This is from a trading point of view."
Professor Abu-Hijleh: "I think people who look at it from this point of view are very narrow-minded. You shouldn’t look at the outlay cost. It’s about the bigger cost picture, the net cost."
Volker Ruehle: "With Ecophit, the bigger the building, the bigger the savings. A 5,000m² installation of Ecophit and AC is much cheaper than conventional AC. This is what we got from the cost comparison analysis we did. Anything less than 5,000m² is almost a balance."
Alistair Davis: "If you can show that cost payback to a client then that will make a difference. As a consultant, at a concept stage, we need to show those details."
Dr. Mahmoud: "In trading it is difficult to convince people unless this is presented as a comprehensive idea. But this product is the future. It has a big potential for the Gulf, which will follow the UAE.
"We have Estidama in Abu Dhabi and Dubai is doing almost the same now. They are not looking at the expenses but at the green building side. From an ASHRAE point of view we are always looking at hospitals.
"Also, maintenance: an FCU has a motor that can get short circuited and go on fire; it has a coil that can get fungus and gets contaminated; it has to be cleaned and maintained; even the drip tray can leak water; printed circuits can be a problem.
"This saves a headache from the maintenance point of view. It is a system that can be installed in a short time but will remain for 10 or 20 years. It has big potential but it perhaps needs some more enhancement."
Bjorn Viedge: "At ALEMCO we’re very proud to be in a partnership with SGL to introduce this product. We were excited when we first had a meeting, hence the reason we went ahead with the test-bed. From a contractor’s perspective, what we think is beneficial, they’ve come up with a huge range of flexible products in many different ceiling panel configurations.
"They are easy to install, very much a plug-and-play type device, which is easy for the artisans to work with. There’s not a great deal of commissioning that’s required to go with the product once it’s installed.
"Obviously, the maintenance and DLP [defects liability period] makes it much easier for the contractor. Also, coordination of the ceiling space – MEP contractors’ biggest problem is large ducts and cable trays.
"If you can do away with the lightweight or GI [galvanised iron] ducting, you save a big portion of time. As a company we’re trying to embrace sustainable technologies and we believe this has a place in the marketplace. We’re finding more and more that government is trying to legislate energy efficient designs. I think this is the way the industry should be looking."
Name: Volker Ruehle
Company: SGL Group
Position: Middle East Consultant
Name: Jeán van Loggerenberg
Company: CKR Consulting Engineers
Name: Alistair Davis
Company: Black & White Engineering
Position: Associate Director
Name: Mohamed Elmasry
Company: Green Vision
Name: Professor Bassam Abdel-Karim
Institution: The British University of Dubai
Position: Dean and Atkins Chair
Name: Dr. Ahmed Alaa Eldin Mohamed
Institution: ASHRAE Falcon Chapter
Position: Regional Vice Chair
Name: Bjorn Viedge
Position: Commercial Director