Electronic oversight

By Tristan Wiggill

Plumbing Africa looks at building management systems (BMS) and how they are used to enhance and maximise design elements, as well as monitoring and controls.

PA BMS 1A basic illustration of the ins and outs of a BMS. 
Image credit: Pixabay

A BMS is a blend of hardware and software-based control systems installed in buildings to control and monitor the building’s mechanical, electrical, and utility equipment.

Mechanical systems typically comprise the HVAC, plumbing, firefighting, and STP equipment, while the electrical services manage the electrical DBs, lighting control and monitoring, generator sets, and UPS equipment.

Water-side commissioning comprises individual commissioning of water-cooled chillers, air-cooled chillers, cooling towers, primary pumps, secondary pumps, VFDs, and associated field devices. It is necessary to measure the values of each field device and other connected points individually before putting them into logic.


The efficient use of water requires management and education.


Meanwhile, utility services look after the lifts, fire alarm, security, and public address system equipment.

INFORMATION SOURCE

A BMS system collects the operating information required for intelligent building management. It analyses the operation of the building systems by viewing all important temperatures, humidities, and equipment status.

A BMS can furthermore automate some control strategies, such as turning equipment on or off according to a time schedule. They allow operators at the BMS work station to view key information about the building and give them control over some of the equipment in the building.

PA BMS 2Most new buildings incorporate a BMS and they can also be retrofitted to older buildings. 
Image credit: Pixabay

A building’s BMS will maintain and provide an audit of what happened and when it happened. It keeps historical data for selected information (like temperatures or humidity levels). Alerts are given to the operators when readings fall outside a normal range.

By implementing this technology, a BMS saves human resources, enhances the productivity of occupants (especially in office environments), prolongs equipment life, and most importantly, saves energy.   

EDUCATION

Chris Kyle, general manager at Calafrica Hydronic Solutions, says these are systems that are specified and installed into water supply installations of buildings. These systems transmit notifications of the performance of the water reticulation system and its components to a centrally located control and monitoring room where information is logged and displayed on an enunciator and data panel.

“The BMS would, for example, sense the water temperature in hot water storage vessels and elsewhere in the hot water reticulation system. This is important in terms of legionella control while also forewarning of an impending system fault or notifying of a present fault in the hot water generation system. Another example would be to monitor the level of water in a reserve water supply tank, as well as the performance of delivery and hot water circulation pumps and so on.”

“It would indicate a fault in that system. For example, if the temperature dropped below the desired level, a BMS would notify an enunciator that there is a fault there. BMS systems are also used in terms of water supply at water meters, where electronic sensors are used. That information is transferred to the central control room where it can be monitored,” he says.

Volumes of water can be measured, for example, on the incoming mains supply. “The building would have a bulk water meter, which sends a signal or information to the central control room of the bulk water supply. That can be monitored on a daily or hourly basis if so desired, or any desired period of time. This means the total volume of water used can be monitored and checked to see if it is feasible per capita for the population within the building,” says Kyle.

PA BMS 3Information collected from several devices is analysed in a main/central control room. 
Image credit: Pixabay

He says that “One would have sensored water meters. For instance, on the tee-off from the building’s water reticulation system to various facilities, such as ablution blocks, kitchens, separate tenants, and irrigation systems, so that the amount of water being used by each of those facilities can be monitored and therefore managed.” The total sum of all the water used must match up to the reading of the bulk water meter.

In this way, one can detect whether there are any losses of water, bearing in mind that the use of water has to be managed. “It becomes an educational thing. One needs to educate the people who are occupying the building as to the efficient use of water. For example, in a kitchen where staff could be incentivised and shown efficient ways of using water, instead of leaving taps running while they are washing up. You can only manage what can be measured, and management is at the crux of water demand management,” says Kyle.

One should establish if hot water is absolutely necessary for certain buildings. Questions should be asked such as: Is it really a requirement in the climate? Do we really need hot water in an office block — other than in a kitchen — where a point-of-use water heater could be used, thus saving a lot of energy?

ABNORMALITIES

The BMS would also be used to detect any abnormalities, such as possible leaks and loss of water due to failure of materials. The BMS would be used to notify the operator of the correct functioning of various pieces of equipment in plant rooms or help to determine the state of collected grey water.


Everyone should be looking to specify and install water-efficient fittings.


“Coupled to this, everyone should be looking to specify and install water-efficient fittings like shower roses,” he motivates. These should not yield more than 10 litres a minute. Wash handbasins should not yield more than three to four litres a minute. One of the big users of water is the flushing of toilets, which also relates to education of the user.

“Efficient equipment must be specified and installed. The whole protocol of this system would be that companies or operators of buildings become very aware of the efficient use of water, which can only be done through management and through proper maintenance schedules.” 

Once a management system is put in place, it has to be maintained and there should be a proper and duly qualified organisation or maintenance team on hand to ensure that maintenance schedules are adhered to. They must check the equipment for proper operation and measure what is actually happening against what should be happening. “South Africa is the polar opposite of Europe; we have a non-maintenance culture,” Kyle laments.

PA BMS 4Both wired and wireless BMS are in use today. 
Image credit: Pixabay

AWARENESS

A BMS is purely a method of managing the use of water. Most big corporates and new buildings that are erected incorporate a BMS. These protocols are aligned with 'green' building practices. There is a moral issue at play today and most companies want to make it known that they are water and energy efficient. Architects and engineers have become highly aware of this, too. There has been a change in thinking and it has become common practice to incorporate a BMS.

It is important that the people receiving data from a BMS understand what it is saying. It is equally important that the plumbing fraternity understands the protocols. They need to upskill themselves in terms of BMS installation and in terms of the advisory information that they provide to clients. 

LEAKS

There are different types of building management systems, some are wired and others are wireless. 

“There are systems, like for instance with geysers, where a tray underneath collects water from leaks. An electronic device comprising two probes senses that water and switches off the water supply to the geyser,” says Patrick Gordan, specialist manager for Grohe, Cobra, and ISCA.

“You would only have a BMS in an office block; I cannot see it being used in residential areas and homes. It is a whole system that needs to be developed. You would have to have water meters that check water flow and you would need to put parameters on it so that if it goes above a threshold of usage, it communicates with a signal, allowing the BMS operator to isolate that area,” says Gordan.

The idea is to design buildings that use a minimum amount of water. It is about making sure you have flow restrictors on all the taps. One can retrofit these flow restrictors to save water. A normal tap typically flows at 30 or 40 litres per minute. This can be limited to around six litres per minute.

“But, even with retrofitting water-saving devices, you will find that big corporate companies are unlikely to implement them. Many people also believe it compromises user comfort, even though pressure-compensating flow regulators produce — by means of an O-ring — a constant flow rate, regardless of pressure fluctuations,” says Gordan.

PA BMS 5A BMS can help identify leaky pipes or pressure irregularities. 
Image credit: Pixabay

Many water-saving devices are nothing more than simple washers with holes in them. At a given pressure, they produce a defined flow rate. “We use a pressure-compensating flow restrictor, which is open until water flow gets to six litres per minute. If you have something with a small hole, fragments of dirt can block it, where this one contracts and relaxes with water pressure,” Gordon says.


Click below to read the January 2018 issue of Plumbing Africa

PA JAN2018

Search

 PAClick Here Blue

 

 


PA PLUMBDRAIN logo 150 PLUMBING Online logo TP SA Plumbers Handbook Logo

Product of

IMD logo White

Interact Media Defined (IMD), is one of South Africa’s leading multi-media magazine publishers READ MORE

Our Products

building LOGO white

Water Online logo white 200

HVACR Online logo 200

mining LOGO whiteCLA Online logo white MM

Talk to us

JHB T : +27 (0) 11 579 4940
CPT T : 0861 727 663
E : admin@interactmedia.co.za

13A Riley Road, Bedfordview,
South Africa 2007

© Interact Media Defined