Considerations for retrofit commercial water heating

July 25, 2017

Commercial water heating is a very different entity to domestic – while many UK homes can be fairly uniform in their requirements, commercial and industrial water heating requirements can vary hugely depending on a range of factors such as sector, building size and peak usage.

Retrofitting brings its own challenges, particularly when a specifier or installer is dealing with a building that may have existed for decades, and with its own antiquated water heating system that needs significantly enhancing or a total replacement.

Either way, whether it be a leisure development such as a hotel or restaurant, an office block, or other light industrial building, there will likely be a requirement for large flow rates and water storage.

For water storage, there are a number of practical issues which first need considering.

• How much space is available? A building’s layout and location can provide a real challenge, particularly if there are low ceilings, concealed areas and existing/new equipment installed. Even with well thought out design plans, installers often do not know what type of difficulties they could face until they arrive at a project.

 

• Building access can also cause problems, both for installation and for regular maintenance, so it is essential while designing and specifying to be aware of how you intend to bring boilerequipment in and also how you intend to be able to access the system once it is in place.

 

• Connecting to an existing pipework system is a task to be aware of; it can be very expensive to fully replace pipework and flange connections, particularly in larger buildings. Often a preferred option is chemical cleaning, however caution is required dependant on pipework condition.

 

• What are the hot water demands for the building? The flow rates required will depend on the regularity and timing of use – for example a sports club or gym may need a large number of showers available at the same time for specific times of the day or week, but be resting for the vast majority of time. Whereas an office building will require a smaller but steady throughput volume in day-time working hours.

 

• What about energy and fuel types? How is the hot water to be heated? Most systems will have some kind of heat generator that is then feeding the coil within the tank in order to heat the water. Coil sizing can vary on many factors such as water flow and return temperatures, flow rate and pressure drops – therefore it must be sized correctly for optimum performance. Electric immersion heaters are still widely used either independently or in conjunction with a coil-fed system and are sized for efficiency and recovery times.whitely mill commercial app

For taller buildings with a number of stories or floors, there is also the vital issue of water pressure. Standard designs offer a working pressure of 6 Bar. For high-rise commercial office blocks for example, this can be an issue if the heating vessel is situated in the basement with water required to be pumped to numerous floors above. Consider that for 10m in height a system loses 1 Bar of pressure, so ancillary pumps would have to be specified. This adds cost, complexity and on-going running costs will increase.

It is important that the water vessel has the structural integrity and quality to handle a higher pressure so 10 Bar rating is specified.

Operating regularly will cause day-to-day wear and tear to an unvented water heater, particularly for systems using either an external pressurised expansion vessel or a floating baffle which will have an air gap that frequently needs recharging.

A unique solution developed by Fabdec for the domestic market has substantially reduced the need for maintenance, creating a totally self-sustaining system based on the Venturi effect, so named after Italian physicist Giovanni Battista Venturi.

This is the reduction in pressure that results when a fluid flows through a constricted section of pipe with no discernible restriction to flow rate.

In the process, a fluid's velocity must increase as it passes through a constriction in accordance with the principle of continuity, while its static pressure must decrease. Any gain in kinetic energy a fluid may accrue due to its increased velocity through a constriction is balanced by a drop in pressure.

It is the mixing of liquid with air – or more specifically the induction of air bubbles into the liquid – that makes the patented ‘Self-Sustaining System’ 3S Technology unique, with the system now able to maintain the internal air gap as hot water is drawn off further upstream in typical usage. As it replenishes the internal expansion device permanently, there is no need for recharging or regular servicing.

stuart doggrellNow being developed to cater for higher throughput volumes the 3S Technology will offer the same benefits to the commercial sector where the maintenance saving alone during the product life-cycle could be quite extensive.

 

Flexibility is key for commercial retrofit and as an independent manufacturer this is one of Fabdec’s strengths; we have the ability to produce stainless steel vessels up to 30,000 litres,tailored specifically as we understand that every project is different.

www.fabdec.com

By Stuart Doggrell, General Manager – Water Heating, Fabdec

Add new comment