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Accurate measures

Scalpello explains why ultrasonics are the future of metering

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Homeowners are expressing a preference for consumption-based water billing.
Homeowners are expressing a preference for consumption-based water billing.

Edward Scalpello, head of sales and marketing at Diehl Middle East, explains why ultrasonics are taking over from mechanical metering, and how technology could revolutionise the way utilities bill for our water.

Founded in the German town of Wroclaw in 1862, Neptun started out producing fittings for water and gas installations; some years later, having developed and produced the world’s first Woltman bulk water meter that same company, now Diehl Metering, is at the forefront of metering technology across the world.

“We’ve been making water meters for 140 years,” says Edward Scalpello, head of sales and marketing, “but they’re a little bit different today than the ones we were producing 140 years ago.”

He’s right, too. With meters covering water, thermal energy, gas and electricity and a variety of innovative automatic meter-reading technologies, the company’s factory is still in Germany, but it supplies meters to some of the Middle East’s leading developments and utility companies.

“We’re using some really sophisticated technology,’ says Scalpello, “including ultrasonics for efficient and high accuracy readings. Accuracy is important; if you have an inaccurate meter, the consumer doesn’t know whether they’re spending the right amount of money, and the utility company doesn’t know if it’s charging the correct amount.”

Having captured an estimated 50 to 60 per cent of the UAE’s district cooling metering market, the company is aware that metering is a controversial topic in the region, especially with the new Strata law that’s seeing the maintenance of developments handed to homeowner associations.

Combined with advances in equipment and changes in attitude that have seen a recent emphasis on consumption-based metering, companies such as Diehl are taking steps to ensure the technology is widely available.

“Homeowner associations are made up of household owners; they could be bankers or shopkeepers, but they’re not metering or chilled water specialists,” says Scalpello.

“Suddenly they’ve been given a legal responsibility to manage an apartment block and they’ve got no experience, so we’re trying to educate people into what’s available and how it all works.”

Emphasis on education
In terms of costs, Scalpello is aware that continuing to educate people as to the advantages of accurate metering is crucial.

“As a home owner you’ve got to think long term. Retrofitting meters can be expensive because the only way is to drain the system or freeze the pipe, and the preferred location is always outside the apartment, often requiring cutting into ceiling panels and redirecting pipes to make more room – it’s very specialist work,” he says.

“Trying to get developers to spend a little more during the building stage is a difficult task, but convincing homeowners is fairly simple because they understand the value of having consumption-based billing.”

According to Diehl, the UAE is an early adopter of district cooling technology, with Scalpello citing the climate and size of the country as chief factors. “This is an extremely hot country, and small, so you need efficient use of energy – district cooling makes efficient use of energy.

If cold water is pumped directly to your building, that’s got to be more efficient than having a huge electricity guzzling AC unit on your roof,” he says. “It’s a more ecologically suitable solution in this part of the world.”

An emphasis on technology in recent years has seen the accuracy of meters improve, with the current trend for using ultrasonics to measure consumption not just in district cooling applications, but also for domestically supplied water, where one of the world’s highest daily consumption rates exists. DEWA is currently completing trials of Diehl’s flagship water meter, the Hydrus.

“Meters of old used moving parts to measure flow,” says Scalpello, “but in this part of the world there’s a lot of dust in the atmosphere, sediment in the water and the biggest problem here is temperature and humidity, so ultrasonics are the way to go because such meters are not affected by any of these factors.”

So how does it work? Two transducers in the flowmeter (pipe) work like miniature speakers, sending out ultrasonic pulses. Underneath these are two reflectors, serving a dual purpose.

“Firstly, they direct the ultrasonic pulse. You send the pulse in one direction with the flow of water, and it’s picked up by the second sensor, which sends another pulse in the reverse direction,” Scalpello explains.

“The pulse going with the flow of water is going to take less time than the pulse going against it, and from this we can calculate the flow.”

A secondary purpose of the reflectors is to help make sure the flow through the pipe remains stable.

“Turbulence in a pipe can adversely affect the accuracy of the measurements, and if the meter is near an elbow it can produce swirling. The reflectors force the water in a certain direction to avoid this, meaning the flow of water through the pipe is always even. That you have water constantly moving in a set pattern helps to stabilise the meter itself – it’s simple, but sophisticated.”

The metering of chilled water for district cooling is virtually the same, but requires the addition of temperature sensors. “You can’t just measure the flow of chilled water,” Scalpello explains.

“The flow doesn’t tell you enough, so you have to measure the difference in temperature. We have a temperature sensor on the inlet pipe carrying the chilled water to the apartment/villa, and one on the outlet pipe carrying the (warmer) return water that’s released its cooling energy at the site, so we’ve got information on how much water is being used, and also what the temperature difference is.

Using a formula the electronic calculator unit can calculate the energy consumed, and the customer is charged for the kilowatt hours per month for the energy consumption.”

With advanced systems in place for the measurement of water usage, it stands to reason that the data collection methods for billing are equally high-tech, too.

“We’ve actually got the region’s largest wirelessly operated auto-meter reading system,” says Scalpello.

“An M-BUS module collects data from all the meters in a building, which is then stored in a data-logging device known as an IZAR Centre. We can collect the data in several ways, including via the internet – our company can connect from anywhere in the world and provide the data, usually in the form of an excel sheet, which can be given to the company doing the actual billing. The IZAR Centres also store each meter’s data for a year, aiding resolution of consumer consumption-related issues.”

Walk on by
Diehl’s meters can also be used as part of a ‘walk-by’ system, such as the installation in Jumeirah Beach Residence, which contains 7,300 meters all transmitting data wirelessly.

A repeater on every other floor collects data from each meter remotely and transmits it remotely, allowing a meter reader to walk past the building with a hand-held device, automatically picking up all the serial numbers. An advanced enough system to allow data collection to take place at speeds of up to 70km/h, it’s a viable ‘drive-by’ service, utilised in Europe by dustcarts fitted with receivers.

In regard to the stability of the systems, the repeaters on every other floor are a failsafe. “We use an internationally standardised radio frequency designed specifically for such applications, with good penetrative and interference-resisting capabilities,” says Scalpello.

“You could probably get away with just a couple of repeaters in the building, but just to be sure we install more to ensure 100 per cent coverage all the time. Importantly, we read the meters daily so we know within a maximum of one day whether there’s a problem with the meter or the flow through it, or whether it’s been tampered with.”

With the UAE historically using mechanical metering, competition is hotting up to install ultrasonic technology in new-build projects. Scalpello is confident that 2011 is shaping up to be an encouraging year, with education of utility companies, contractors and homeowner associations still high on the list of priorities.

“There are a lot of developments where the developer didn’t put sub meters in - only bulk meters - and this has proved to be a headache for the homeowner associations, which would generally prefer consumption-based billing rather than area-based,” he says.

“We’re providing intelligent metering solutions here, and we’re also talking to all stages of the developments from utility companies and consultants to developers and contractors, with our educational style of sales presentation having rewarded us with more than half of the currently available market.”

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