The AEL Techno System DHW Packaged Plate Heat Exchangers can be programmed to thermally scour the DHW circuit by using our Anti Legionella bypass valves with a two way valve that eliminates legionella and isolates the DHW outlet whilst avoiding any scalding during the Anti Legionella cycle. 

The AEL Techno System Anti Legionella function can be programmed with 64 settings with a visual message on the display in case of probe malfunction or an optional audible alarm can be provided.

The four main factors that influence the growth of legionella are. 

1. TEMPERATURE 
2. WATER FLOW / STAGNATION 
   
3. PARTICULATE MATTER
   
4. NUTRIENT SUPPLY

 TEMPERATURE 
1. Legionella exists in low numbers when the temperature is below 20°C
2. Between 20°C and 37°C the growth is rapid and slows down as it reaches 45°C
3. At 50°C 90% of legionella dies off within two hours and at 60°C legionella are killed off within two minutes. 

WATER FLOW STAGNATION
Low or no flow rate of a fluid may cause stagnation which will encourage the growth of legionella.  

PARTICULATE MATTER
Particulate matter may offer protection to the legionella bacteria where they may be killed off in adverse conditions. 

NUTRIENT SUPPLY
Common organisms such as bacteria serve as a nutrient for legionella. 

USING A  PLATE HEAT EXCHANGER TO REDUCE THE RISK OF LEGIONNAIRES DISEASE
Because a Plate Heat Exchanger instantaneously heats up fluids and does not have any storage, they practically eliminate the possibility of any dangerous bacteria growth such as legionella. 

A standard AEL Plate Heat Exchanger can heat up domestic hot water from 10°C to 60°C instantaneously at a continuous flow rate of 5 L/S. 

The AEL Plate Heat Exchanger plates are made from 316 Stainless Steel that has a corrugated profile that creates turbulence as the fluid flows through the unit which also scrubs and also helps to reduce any particulate deposits forming on the plates. 

It is worth noting that using a plate heat exchanger can practically eliminate legionella from the most common sources which have been found to be: 

1. COOLING TOWERS and EVAPOURATOR CONDENSERS. 
2. HOT WATER SYSTEMS 
3. HUMIDIFIERS and AIR WASHERS 

A GUIDE ON HOW TO MANAGE THE RISK OF LEGIONELLA
It is important that every installation has a well thought through scheme to prevent or minimise the risks of legionella. 
It is important that a responsible person is employed to manage and implement precautions. 
It is important that records are kept of the precautions taken. 

Contact Us 

• www.aelheatexchangers.co.uk 

• Tel: 0151 336 8837 

• sales@aelheatexchangers.co.uk  

• technical@aelheatexchangers.co.uk

AEL are an authorised distributor of genuine Alfa Laval spare parts, with access to the database of original designs going back over 30 years. This allows us to replace your existing Alfa Laval Plate Heat Exchanger using the same design duties it was originally supplied with.

When you purchase genuine Alfa Laval spare parts from AEL, you can be confident of receiving a direct replacement that is guaranteed to be fit for purpose, ensuring your equipment is quickly restored to peak performance first time.

If you require a replacement Alfa Laval Plate Heat Exchanger, please provide us with the serial number from the rating plate of your existing PHE. This enables us to access the original duty design and supply an exact replacement or one with an updated or modified design duty.

To email your requirements to our Technical Sales Office, please click on Genuine Alfa Laval Spare Parts & Replacement Heat Exchangers.
You can also telephone 0151 336 8837 to discuss your requirements, or visit our website: http://www.aelheatexchangers.co.uk

The practice among some manufacturers and suppliers in the UK of using unrealistic sizing tolerances when designing Plate Heat Exchangers to offer a cheaper option at quotation stage creates uncertainty about the actual performance of the heat exchanger design provided, leading to higher operating costs for the end customer.

AEL and Alfa Laval are committed to raising awareness about the problem and are highlighting the solution of using the AHRI Performance Certification as a means of guaranteeing that each Plate Heat Exchanger we design performs exactly as expected.

The stated performance of some Plate Heat Exchanger suppliers in the UK does not always live up to expectations. For many years, it has been a common, albeit hidden, practice in the industry for some suppliers of Plate Heat Exchangers to overstate the actual duty calculations when sizing their heat exchangers to offer a cheaper alternative. This is currently the biggest problem facing the Plate Heat Exchanger industry in the UK today, and the Specifying Engineers that pride themselves in producing well‑designed installations need to be made aware that there is a solution.

Heat duty calculation is an important step in the specification process and is essentially an assessment of the requirements for maximum performance by the consultant and designer of the heating or cooling system. “Adjusting” these calculations has become a weapon of deception in the battle to win contracts. Manufacturers manipulate calculations so that component costs can be minimized and a smaller plate heat exchanger can be offered at an attractive price. However, the result is that end customers get under‑dimensioned heat exchangers, leading to higher system‑wide energy use, higher operating costs, and compromised environmental performance.

The widespread practice of “recalculation” is a big problem for everyone in the industry. It makes it harder to choose a heat exchanger that will provide the required performance and increases the risk that it will underperform. It creates uncertainty for everyone involved in recommending, selecting, and using heat exchangers – consultants, specifiers, and end customers – and undermines confidence in the industry.

By the time the problem is detected, it is too late – a major investment has already been made, and the underperformance can only be revealed in the higher‑than‑expected energy costs to the end user.

The only way to ensure the quality of the materials being used and the thermal design is accurate from the start is to specify AHRI Approved Plate Heat Exchangers. Such is the belief and commitment of AEL and Alfa Laval to Performance Certification in the UK that we provide a 3‑year warranty with all our AHRI Approved Plate Heat Exchangers.

The Air‑Conditioning, Heating, and Refrigeration Institute (AHRI) is the only independent third‑party nonprofit organization that certifies the performance and materials used in Plate Heat Exchangers globally. The AHRI Liquid to Liquid Heat Exchangers (LLHE) Certification Program provides third‑party verification of thermal performance and materials used – it gives independent assurance that the plate heat exchanger you have been quoted will perform in accordance with the manufacturer’s published ratings and has been designed with a reasonable sizing tolerance.

Independent Performance Certification creates a level playing field for comparing the thermal performance and price/performance ratio of plate heat exchangers, which reduces time spent on the selection process and ensures the optimum product is chosen. End users benefit from operating a more energy‑efficient system with optimized energy consumption and significantly reduced lifetime operating costs. As calculations have already been verified, costs are lower for field tests and additional component performance margins. It also enables end users to reach targets for power consumption and climate control, as they can be confident that heat exchanger capacity will be sufficient to meet set performance goals.

AHRI Performance Certification eliminates cheating from overstating thermal performance for financial gain, which enhances confidence in the industry and provides peace of mind for those who rely on system performance – suppliers, consultants, contractors, and end users. In the longer term, performance certification will eliminate concern about calculations and promote a stronger focus on energy efficiency, which will foster innovation and stimulate manufacturers to develop more efficient products.

AEL and Alfa Laval believe in the AHRI certification, and the AHRI LLHE Certification Program is currently the only program available in the world for Plate Heat Exchangers.

The Alfa Laval AlfaQ series were the first to be AHRI certified, and Alfa Laval has accomplished a 100% success rate in the AHRI Performance Certification Program since the start. AEL and Alfa Laval have chosen to take an active role in promoting AHRI certification. From every perspective, AHRI Performance Certification is better for everyone involved in the process of designing, producing, selecting, and operating plate heat exchangers.

AEL and Alfa Laval are convinced that the AHRI Performance Certification is an important step in creating a sound Plate Heat Exchanger market in the UK that benefits the whole industry and the end users that have trust in our expertise when designing a Plate Heat Exchanger for their application.

Should you have a project where you would prefer to have guaranteed performance certification, please contact AEL and we will be delighted to provide you with a quotation, specification data sheets, and a drawing of your Alfa Laval AHRI Approved Plate Heat Exchanger.