Tag Archive for: soft water

Adveco ADplus Instantaneous Commercial Water Heaters

  • A range of three compact floor-standing commercial instantaneous gas-fired condensing water heaters with built-in storage tank
  • Perfect for all water qualities with a 5-year warranty on burner and heat exchangers

Commercial hot water specialist Adveco, announces the Adveco ADplus range of high-power gas-fired condensing water heaters featuring an integrated 120-litre stainless steel water storage tank for instantaneous continuous and on-demand domestic hot water (DHW). The ADplus is available in three variants – 70 kW, 115 kW and 140 kW rated heat output.

“Designed to provide a compact, high capacity and reliable method for delivering instantaneous hot water to a commercial building, ADplus is a tough all-rounder,” said Bill Sinclair, technical director, Adveco. “It is perfect for a wide range of applications – from small instant demands to large-scale continuous DHW needs. With minimal NOX and CO emissions, the ADplus range is an eco-friendly way to serve your building’s DHW system. The rugged construction, supported by Adveco’s in-house warranty engineers, provides real peace of mind for your investment.”

The 115 kW and 140 kW ADplus variants offer two high-quality heat exchangers. Constructed from corrosive-resistant continuous run titanium-stabilised stainless steel, these provide balanced highly efficient operation and built-in redundancy. Heat is provided by the patented Fecralloy premix burner fed by a consistent balanced air/gas ratio at each point of turndown. The high modulation ratio results in high combustion efficiency with ultra-low NOX and CO emissions. A built-in flue back preventer on the combustion circuit prevents possible flue gas recirculation between different exchangers.

The tough, stainless steel 120-litre storage tank is provided with electronic anodic protection and high-quality polyurethane thermal insulation. This enables the ADplus to serve as a semi-storage system, providing always available and instantaneous supply with quick recovery times for continuous provision of DHW. For on-demand needs, ADplus heats what is necessary, with no ignition for smaller withdrawals providing considerable energy savings. When heat is required, the condensing technology provides up to 30% savings in fuel consumption. To reduce acidity build-up caused by the condensing process, the ADplus is equipped with a condensate acidity neutraliser, specifically sized to restore tolerable pH values. With the anti-corrosive construction, ADplus can be used with soft and softened water. For harder water, the recirculating pump regulates the correct water flow according to inlet water hardness helping to prevent the formation of limescale on the heat exchanger surface, ensuring high performance throughout its life cycle.

The extremely compact Adveco ADplus is designed to pass through a standard 65cm wide door for trouble-free installation and offers front access to all inner components for quick, easy maintenance. The integrated cascade controller supports full temperature control and self-check maintenance functions for up to 8 units. The controller accommodates 0-10 input, MODBUS communication, and alarm output for seamless BMS integration.

Additional Information

  • High capacity DHW production
  • Compact floor-standing arrangement
  • High-efficiency pre-mix burner with a five-year warranty
  • Extremely high-quality AISI 316Ti heat exchangers with a five-year warranty
  • Ultra-low NOX emissions, class 6 appliance at 27 mg/kWh
  • CO emissions 19ppm
  • High maximum run pressure up to 11 bar
  • Flue gas non-return valve for overpressure cascade flue systems
  • Standard flue systems using low-cost 110mm diameter PP
  • Available using natural gas or LPG

Read more about the Adveco ADplus instantaneous commercial water heater range 

Adveco AD: Providing Continuity of Service in Soft Water Conditions

• The Adveco AD range of compact commercial semi-instantaneous gas condensing water heaters
• Perfect for applications requiring direct contact with soft and softened water
• Highly efficient modular design offers continuity of service in one appliance.  Or can be deployed as an on-gas system backup for larger-scale heat pumps projects

Commercial hot water specialist Adveco, presents the new AD range for 2022. This latest generation of sleekly designed, modulating commercial floor-standing gas condensing water heaters is conceived to be used with a buffer for high demand semi-instantaneous hot water applications in sports & leisure centres, hotels, spas, schools, stadia, and large commercial buildings.

With each water heater composed of one to four 70 kW heat exchangers, the Adveco AD range offers appliances from 70kW up to 280 kW. This approach optimises the supplied output (up to 160 litres/minute) ensuring maximum efficiency when providing DHW. Models with multiple integrated heat exchangers offer load balancing for optimal long-life operation and inbuilt redundancy guaranteeing continuity of service.

Bill Sinclair, technical director, Adveco said,” As well as the continuity of service seen in individual units, the AD is perfect for integrating into large scale heat pumps systems seen in hotels and hospitality. So long as there is an existing gas connection, AD can be used to provide a cost-effective and easy to accommodate back-up for assured continuity of business-critical water heating.”

Tough and efficient, AD water heaters are all equipped with premix burners made of Fecralloy metal fibre for large modulation range with excellent functionality at extremely high temperatures. Using a premix burner ensures the AD requires less gas, making it more cost-effective, plus reducing harmful NOX and CO emissions.

The titanium-stabilised stainless-steel construction of the AD range’s heat exchangers is the perfect response to counter corrosion typically seen in high-pressure circuits in soft, or softened water applications. The heat exchangers work with an electronically controlled variable stainless steel modulating recirculating pump and two-way motorized valves to ensure a perfect balance between water flow and supplied output.

The AD range can also be configured to operate in a cascade of up to eight water heaters. The AD’s controller provides full temperature control and self-check maintenance functions. The controller also accommodates 0-10 input, MODBUS communication, and alarm output for seamless system integration.

Compact, lightweight yet still powerful, the Adveco AD’s patented space-saving design makes it equally applicable to both new projects or renovation work where a lack of space would traditionally stall or quickly drive up costs of a project.

Additional information
• Five-year warranty on AISI 316Ti heat exchangers with
• 10-year warranty on pre-mix burner
• Compact floor standing arrangement: AD 70T & AD140T H1180xW600xD945mm / AD210T & AD280T M1880xW600xD896mm
• High maximum run pressure up to 11 bar
• Low emissions, built with Class 6 technology for NOₓ at 27 mg/kWh GCV
• Available for natural gas or LPG
• Acid condensate neutraliser included
• Ideal for soft water applications. Hard water areas over 150ppm require use of a water softener down to 100ppm.
• Supports standard flue systems using low cost 110-160 mm diameter PP

FUSION Commercial Hybrid Hot Water Systems from Adveco

  • FUSION is a complete range of low carbon hybrid heat pump and electric hot water systems
  • Resilient stainless steel water heating suitable for all UK regions
  • Compact design for new build and refurbishment projects seeking greater sustainability

Commercial hot water specialist Adveco, introduces the FUSION FPH-S range of low carbon, all-electric, packaged hybrid hot water systems. FUSION harnesses Adveco’s FPi32 Air Source Heat Pumps (ASHP), a high-pressure ATSH calorifier with electric immersion, controls, and metering to provide a reliable, high-temperature, sustainable and cost-effective system for new commercial build and refurbishment projects.

FUSION is available in 16 pre-specified variants with 6 or 10 kW preheat and 9 or 12 kW electric top-up, with capacities ranging from 200 to 500 litres all rated at 10 BAR for high-pressure applications. Able to meet a range of continuous capacity hot water demands from 257-377 litres/hour makes FUSION highly adaptable for a wide range of commercial buildings.

The FPi32 ASHP is specified to supply a working flow of 50°C for system preheat throughout the year, even when ambient air temperatures drop as low as -25°C. Electric immersion top-up then raises system temperatures in the calorifier to the necessary 60°C to meet commercial requirements for safe hot water demands. The stainless steel construction of the ATSH also makes it an excellent all-rounder, resistant to soft water corrosion and, with FUSION’s unique low electric immersion heat intensity (6W/cm²), is more resistant to scale build-up in hard water areas.

The physical design, dedicated controls and integrated metering ensure the ASHP preheat, and immersion work seamlessly to deliver the highest operational efficiencies. This enables FUSION to make the greatest gains possible from the heat pump, even when ambient temperature and system demands fluctuate. These gains offset much of the direct electrical energy usually required, delivering 53% carbon emissions saving and helping control the operational costs of providing business-critical hot water.

“For organisations with small to medium basin and sink led hot water demands and a desire to embrace a more sustainable business model, the FUSION FPH-S range provides a single, easy to accommodate, highly effective response,” says Bill Sinclair, technical director, Adveco. “By choosing one of these packaged hybrid water systems you gain optimum efficiencies, lower your carbon emissions and can be assured building regulations are being met for your commercial project.”

Fusion FPH-S Features

  • 16 pre-sized variants to meet a wide range of applications
  • 200, 300, 400 and 500-litre capacities
  • 6 or 10kW ASHP preheat
  • 9 or 12kW direct electric immersion heating
  • 257-377 litres/hour continuous capacity
  • 10 BAR high-quality AISI 316Ti and 316L stainless steel vessel (PED (97/23/EC), EN 12897)
  • Dedicated control system for simple operation and maintenance checks
  • Lower global warming potential with R32 ASHP
  • Compact space-saving form factor

Calorifiers and Hot Water Storage in Corrosive Water Conditions

For many companies, the assured availability of hot water is a business-critical issue, but one that can quickly become costly for those operating in the southwest and northwest of the UK, the Welsh coast and throughout Scotland. With a low pH, low total dissolved solids (TDS) and negligible buffering capacity, these naturally soft water areas prove highly corrosive to glass-lined vessels used as calorifiers and hot water storage.

Glass is, given the right conditions, generally resistant to attack from most chemicals and corrosive materials and easier to clean, making it a popular choice for lining steel vessels used in hot water systems. But corrosion is a complex phenomenon, and in naturally soft water conditions, despite the use of sacrificial anodes, glass-lined vessels can rapidly succumb to critical corrosive damage.

Pressure to Perform

In addition, the taller the structure, the greater the pressure requirements on the system, particularly since a common design choice is to locate the plant room in the basement. In order to meet, even small demands with a consistent, strong flow of hot water systems inevitably are oversized, adopting a larger, often bespoke tank.

This immediately exacerbates the existing threat, as oversizing, or the failure to correctly balance water flow also contributes to system corrosion. Oversizing of the pumps leads to high-velocity hot water circulating through the system and suspended solids in the water are driven against the metal leading to erosional corrosion. This process helps accelerate the soft water corrosion at points where water changes direction, such as when passing into or through tanks.

Glass-lined water vessels used as calorifiers and hot water storage under these conditions can potentially fail due to corrosion in a matter of just months – even with the use of sacrificial anodes. For these reasons, manufacturers will reduce or have even ceased to offer warranties on glass-lined products installed in these soft water regions. As a result, their specification into projects in these regions really can be a false economy.

Change to Resistant

Far more resistant to these water-side assaults are stainless steel vessels. Although there is a higher upfront cost, this would be easily offset by the relative longevity of the appliance. However, projects with smaller, yet higher pressure hot water demands, will still face the issue of oversizing. This further extends capital costs, of products, installation and the need for greater plant room space. As a result, project costs can become prohibitive for stainless steel, resulting in the specifying of the less expensive glass-lined alternatives gambling that they will prove resistant enough in the mid-long term.

Adveco addresses these concerns with its ATSx range of compact stainless steel, high-pressure hot water tanks. Specifically designed to serve as buffer vessels (ATSB) and indirect hot water calorifiers suitable for use with lower capacity, high-pressure commercial applications in soft water areas. The ATSx range provides specifiers and contractors with a wide choice of calorifiers and hot water storage vessels all rated to 10 bar as standard, which are by far the most efficient and cost-effective choice for businesses with smaller system demands.

Another advantage provided by the indirect water heaters in this range (ATSI, ATST, ATSH & ATSR) is that due to the transferral of heat through the walls of the heat exchanger element the two fluids do not mix. This allows for more options in terms of the external heat supply and introduces a range of renewable technologies that use other fluids for heat transfer including solar thermal collectors and Air Source Heat Pumps. The twin coil ATSR has been specifically designed for these lower-temperature renewable applications. These calorifiers are also relatively simple to install, since there is no burner, there is no need for a gas supply to be directly connected to the appliance and the is no requirement for a flue.

As with any hot water application, understanding the relationship between storage and recovery, and correct sizing is extremely important for efficient and cost-effective operation. Integrating a stainless steel calorifier within a hot water system gives you a number of design options, with a large efficient boiler a calorifier can be smaller avoiding unnecessary capital and ongoing operational expenditure. At 200 to 1000 litres the ATSx range provides a compact, tough resolution for lower demands applications in those soft water areas. If your project has pressure requirements greater than six bar, then the ATSx vessels are by far the most efficient and cost-effective choice for your project.

If the boiler is smaller, or demands for hot water are greater, then going too small means the storage could prove inadequate and the system will not achieve its operational requirements. For projects with larger demands or requiring greater customisation Adveco can support the project with the SSB, SSI and SST ranges of bespoke stainless steel calorifiers and hot water storage vessels.

Discover more about the Adveco ATSx range.

Learn more about soft water corrosivity.


Adveco commercial hot water and heating. Speak to Adveco about tackling global warming through efficient, low-carbon commercial hot water and heating systems (For schools, hospitals and care homes too!)

Call us on 01252 551 540 or see our other contact details.

 

Adveco ATSx Stainless Steel Hot Water Tanks for Soft Water Areas

  • A complete range of indirect hot water calorifiers and buffer vessels.
  • Corrosion-resistant stainless steel construction for soft water areas.
  • Designed for high pressure, lower demand projects.

Commercial hot water and heating specialist Adveco, announces the ATSx range of stainless steel hot water tanks. The new product range encompasses five classes of vessel up to 1,000 litre capacity at 10 bar as standard to serve as buffer vessels and indirect hot water calorifiers. The range is designed to provide a more economic choice for high pressure, lower capacity commercial applications in soft water areas.

With single coil, twin coil and plate heat exchanger options for maximising transfer of energy, the ATSx stainless steel hot water tanks offer consultants, specifiers and contractors a broader set of options for the storage and delivery of domestic hot water (DHW) in soft water areas for their projects.

ATSI – Single coil indirect water heater.

ATST – Twin coil indirect water heater.

ATSH – Single double-helical high-capacity coil indirect water heater.

ATSR – Twin coil indirect water heater for lower-temperature renewable applications.

ATSB – Storage/buffer tank without coil.

Speaking of the launch of the ATSx range, Adveco’s Technical Director Bill Sinclair said:

“If your project has smaller hot water demands, but with pressure requirements greater than six bar, such as in taller buildings with a basement plant room, then the ATSx vessels are by far the most efficient and cost-effective choice for your project,”

Constructed from corrosion-resistant AISI 316Ti and 316L stainless steel, all ATSx tanks are designed, manufactured, and tested to the requirements of the Pressure Equipment Directive (97/23/EC), EN 12897.

The ATSx range is also supported by a choice of options and ancillaries from Adveco including control and overheat thermostats, destratification pump kits and unvented kits.

For projects with larger demands or requiring greater customisation in soft water areas, Adveco offers its SSB, SSI and SST ranges of bespoke stainless steel calorifiers and buffer vessels.

Discover more about Adveco’s ATSx range


Adveco commercial hot water and heating. For more information about Adveco’s ATSx stainless steel hot water tanks, call us on 01252 551 540 to discuss requirements, sizing etc.

 

Corrosion in Commercial Heating & Hot Water Systems: Part 2

Part 2 – Testing for Corrosion

If your premises are located in a soft water area then you need to be aware of the threats of corrosion to your system, and small leaks in your metal plumbing components could well be a sign of a more serious problem.

Testing water for corrosivity factors – pH, calcium concentration, hardness, dissolved solids content and temperature – as well as dissolved lead and copper due to corrosion is relatively straightforward.

Water hardness.The original accepted measurement of water corrosivity, the Langelier Saturation Index (LSI), was developed to determine whether a water source is potentially scale forming or scale dissolving (aggressive).  LSI, however, was not developed with the intention of testing naturally soft water, so relies on the chemical characteristics of the water, such as pH and especially hardness, to estimate the corrosivity. Positive values are indicative of non-corrosive water, negative LSI values indicate water could be corrosive.

The problem with LSI is that it based upon the oft-cited belief that calcium carbonate scale when deposited in a thin, carefully controlled, uniform layer can contribute to a protective barrier against corrosion. There is little scientific evidence to support this assumption

The highly variable physical and chemical conditions within a commercial hot water system mean it is very unlikely that a deposit of scale would ever be truly ‘uniform’. Deposition would typically be prevalent on the hottest elements of the boiler/water heater, and with the formation of crevices actually drive greater localised corrosivity in a fashion similar to pitting which would lead to the potential failure of an appliance. Additionally, as scale accumulates microscopic deposits of metal can be incorporated generating a ‘mini-galvanic’ effect.

Scale formation in a glass-lined indirect tank

Scale formation in a glass-lined indirect tank

Even without the issues of generating corrosion factors, it is never recommended that scale build-up be allowed in a hot water system. An increasing build-up of scale reduces the efficiency of an appliance by restricting the rate of flow and harming efficient transfer of heat. All of which drives up the operational costs.

For a more accurate prediction of calcium carbonate, and levels of corrosivity, the Ryznar Stability Index (RSI) was developed which considers pH, conductivity in TDS, calcium ions (CA²⁺), bicarbonate (HCO₃) and water temperature. An RSI of 6.0 -7.0 indicates water with little scale and the probability of some corrosion, with higher values being increasingly corrosive. Between 7.0 – 7.5, corrosion will be significant, becoming heavy between 7.5 and 9.0. Results above 9.0 are regarded as intolerable.

Both LSI and RSI are predicated on assessing the level of scale build-up, so an alternative approach is to test for metals concentrations, especially copper, which is achieved by drawing a sample to test directly from the commercial hot water system. Detection of iron, manganese or aluminium impurities in the water can also be indicative of corrosivity as localised deposits can also cause pitting in copper.

The only caveat is that the concentrations in open systems, such as where instantaneous water heaters are deployed, will quickly flush by-products of corrosion out of the system. So regular testing is soft water areas can be advantageous when seeking to prevent serious damage to appliances and associated system pipework.

UK water suppliers will typically provide self-assessment help for establishing local water quality, and can often provide details of most recent water tests based on a business’ postcode. Independent testing is also available, though there will be a cost associated. At Adveco our engineers can help and advise with your water assessment as part of the application sizing process.

Read Part 1 – Recognising the causes of corrosion

Read Part 3 – Preventing Corrosion: Glass versus Stainless Steel

Corrosion.

Corrosion in Commercial Heating and Hot Water Systems: Part 1

Part 1 – Recognising the Causes of Corrosion

Most metals will deteriorate or corrode, sometimes to a more stable chemical state through oxidation or reduction. This occurs over time when metals are in direct contact with any water, rusted iron being the most familiar, but it can also affect copper, lead, aluminium, zinc, and numerous other common metals. This becomes a real issue in water heating and distribution systems where metal appliances and pipes are continuously being attacked to the point of physical failure.

Corrosion in Commercial Heating and Hot Water Systems - Hard and soft water areas of the United Kingdom and IrelandCorrosion is a complex phenomenon, and no single dissolved substance is responsible for making water corrosive. There are several factors that can increase the likelihood of corrosion, especially the natural softness of water. When water passes through limestone and chalk in the ground, such as in the South East of the UK, it will pick up calcium and magnesium carbonates, when these minerals are greater than 280ppm the water is classed as hard. However, in Scotland, the North West and South West of England, and Western Wales, where water passes through hard igneous rock it lacks dissolved calcium and magnesium.  This makes the water naturally purer (less than 100 ppm). This soft water exhibits a low pH, low total dissolved solids (TDS) and negligible buffering capacity, all of which makes it more corrosive.

pH measures the hydrogen ion activity in a solution and is used to express the intensity of the acidity of a solution. Typically, the ideal pH for a commercial hot water system is slightly above 7 on the pH scale. Water with a low pH (below 7) is acidic, which is a problem as acids are compounds that release hydrogen ions which oxidize metal, accelerating corrosion. In general, the lower the pH, the more aggressive the corrosion.

There can be a range of reasons for the formation of anodic and cathodic sites, required to produce corrosion. Different materials used in the manufacture of the appliance or pipework, localised stresses, impurities and variances in the production of the metal, its composition and ‘grain size’ can all lead to surface imperfections. If localised variances are relatively small the anodic and cathodic sites will move around on the surface of the metal leading to a more uniform corrosion which is typically seen as surface oxidation or fouling.

Should the anodic sites be more static, localised corrosion can occur. This form of corrosion – which includes pitting, leaching and galvanic corrosion – is a more serious problem which can more rapidly lead to the failure of an appliance or pipework.

Pitting, one of the most destructive types of corrosion, occurs when there are large differences in surface conditions, leading the anodic and cathodic sites to become stationary. The process is exacerbated by low-velocity conditions, leading to the creation of a pit on the surface of the metal, the water inside becomes isolated and, over time, more corrosive as it produces an excess of positively charged metal cations, which attract chloride anions. In addition, hydrolysis produces hydrogen (H+) ions. The subsequent increase in acidity becomes self-sustaining as the concentration within the pit promotes even higher corrosion rates.

Leaching is the selective corrosion of a single element from the alloy. The most common occurrence in a building’s hot water system is the removal of zinc from brass (a copper-zinc alloy), a process also known as dezincification. Though the copper and zinc dissolve out simultaneously, the copper will precipitate back from the solution. The resultant copper alloy will change from a yellow brass to red colour and exhibit poor mechanical property. Common in cheaper valves and fittings where there is likely to be other ‘filler’ metals in the copper alloy, water containing sulphur, carbon dioxide, and oxygen, low pH conditions, low velocity and high free chlorine radicals drive especially aggressive corrosion causing fittings or valves that move to fracture and leak.
The complexity of commercial hot water systems, especially if the project is a refurbishment, can lead to two dissimilar metals (such as copper and stainless steel) coming into contact with each other and water. Under these conditions the corrosion rate of the more active (anodic) metal increases and the corrosion rate of the nobler (cathodic) metal decreases. This is Galvanic corrosion.

The galvanic scale - Recognising corrosion in commercial heating and hot water systems.When differing metals are connected in a hot water system, the water in contact with both metals acts as an electrolyte conducting the current. The current flows through the water from the positively charged less noble material to the negatively charged more noble material. Where the current leaves the less noble metal, corrosion will occur. As the current is usually greater close to the contact point of the two metals, this is where corrosion will be a greater issue. The higher the metal is on the Galvanic series, the nobler the metal will be, whilst the greater the distance between the two differing metals in the series, the greater the electrical potential will be and the greater the corrosion rate for the less noble metal.

Another major cause of corrosion found in commercial hot water systems is a direct result of oversizing or the failure to correctly balance water flow. An unfortunately common occurrence, oversizing a system not only raises the capital expenditure and the running costs of a hot water system, but the oversizing of the pumps leads to high-velocity hot water to circulate through the system. If there are any suspended solids in the water, they will be driven against the metal leading to erosional corrosion which is typified by smoothly grooved or rounded holes which mirror the directional or turbulent flow of the water. This erosion is most notable at points where water changes direction or is obstructed, leading to turbulence which further increases velocity and therefore the damage. If the high-velocity flow is not addressed quickly it can result in considerable damage, especially to the circulating pipework.

Certain chemicals (such as chlorine, chloramine and dissolved oxygen) can also make water more corrosive. The presence of oxidizing agents such as dissolved oxygen can cause metals to lose electrons and lead to corrosion. The removal of sulphate, or addition of chloride, the Chloride-to-sulphate mass ratio (CSMR) will accelerate corrosion in the presence of materials that contain lead, leaching it into the water. Sulphates inhibit corrosion by forming passive protective film layers and reducing galvanic currents between dissimilar metals, chlorides prevent the formation of such passive layers and stimulate galvanic current. Should the source water contain natural levels of chloride and treatment be installed to remove sulphate, the expectation is this would push the CSMR up and as a result, accelerate corrosion. The base 60°C requirement for commercial hot water can worsen such cases as high temperatures accelerate almost all chemical reactions. As temperatures hit 70°C, which is not uncommon in commercial systems the rate of corrosion will increase.

Read Part 2 – Testing for Corrosion

Read Part 3 – Preventing Corrosion: Glass Versus Stainless Steel