When mixing valves are used at each tap or shower outlet in a DHW system the KW demand can be reduced because the PHE water at 60 oC is automatically blended through a mixing valve with mains cold water at 10 oC to arrive at a pre determined temperature of say 40 oC (as shown below) at the outlet of a shower or tap when required .

The temperature on each DHW circuit outlet can be adjusted at the mixing valve by altering the percentage of hot and cold water mixed to suit whatever is required at each appliance on site.

Each AEL domestic hot water Plate Heat Exchanger whether it is an AEL fully controlled Packaged unit , Brazed Plate or Plate and Gasket type heat exchanger each can be made to suit the temperature you require but most DHW systems are designed to supply water at 60 oC to avoid the growth of legionella .

The designs shown below are based on a flow rate of 60% of DHW from a Packaged Plate Heat Exchanger at 60 oC being mixed with 40% of mains cold water at 10 Oc giving an outlet temperature of 40 oC.

AELTHERM MODEL     DHW FLOW RATE @60 Oc     MAINS COLD WATER FLOW RATE @ 10 Oc.    MIXED OUTLET FLOW AT 40 oC

DHW020510 – 25.2KW         0.12 L/S                                         0.08 L/S                                                           0.20 L/S

DHW025510 – 31.5 KW        0.15 L/S                                         0.10 L/S                                                           0.25 L/S

DHW035510 – 44.1 KW        0.21 L/S                                         0.14 L/S                                                           0.35 L/S

DHW045510 – 56.7 KW        0.27 L/S                                         0.18 L/S                                                           0.45 L/S

DHW055510 – 69.3 KW        0.33 L/S                                         0.22 L/S                                                           0.55 L/S

DHW060510 – 75.6 KW        0.36 L/S                                         0.24 L/S                                                           0.60 L/S

DHW065510 – 81.9 KW        0.39 L/S                                         0.26 L/S                                                           0.65 L/S

DHW075510 – 94.5 KW        0.45 L/S                                         0.30 L/S                                                           0.75 L/S

DHW085510 – 107 KW         0.51 L/S                                         0.34 L/S                                                           0.85 L/S

DHW100510 – 123.9 KW      0.59 L/S                                         0.39 L/S                                                           0.98 L/S

DHW120510 – 149.1 KW      0.71 L/S                                         0.47 L/S                                                           1.18 L/S

DHW150510 – 186.9 KW      0.90 L/S                                         0.60 L/S                                                           1.50 L/S

DHW180510 – 224.7 KW      1.08 L/S                                         0.72 L/S                                                           1.80 L/S

DHW210510 – 262.5 KW      1.26 L/S                                         0.84 L/S                                                           2.10 L/S

DHW2401410 – 300.3 KW    1.45 L/S                                         0.96 L/S                                                           2.36 L/S

DHW2701410 – 338.1 KW    1.62 L/S                                         1.08 L/S                                                           2.70 L/S

DHW3001410 – 375.9 KW    1.81 L/S                                         1.20 L/S                                                           3.01 L/S

DHW3301410 – 413.7 KW    1.97 L/S                                         1.31 L/S                                                           3.28 L/S

DHW3501410 – 438.9 KW    2.09 L/S                                         1.39 L/S                                                           3.48 L/S

DHW3801410 – 474.6 KW    2.28 L/S                                         1.52 L/S                                                           3.80 L/S

DHW4101410 – 512.4 KW    2.47 L/S                                         1.64 L/S                                                           4.11 L/S

DHW4401410 – 550.2 KW    2.65 L/S                                         1.77 L/S                                                           4.42 L/S

DHW4701410 – 588.0 KW    2.83 L/S                                         1.88 L/S                                                           4.71 L/S

DHW5001410 – 625.8 KW    3.01 L/S                                         2.00 L/S                                                           5.01 L/S

DHW5301410 – 663.6 KW    3.19 L/S                                         2.12 L/S                                                           5.31 L/S

DHW5601410 – 701.4 KW    3.38 L/S                                         2.25 L/S                                                           5.63 L/S

DHW6001410 – 751.8 KW    3.60 L/S                                         2.40 L/S                                                           6.00 L/S

DHW6301410 – 789.6 KW    3.80 L/S                                         2.53 L/S                                                           6.33 L/S

DHW6601410 – 827.4 KW    3.98 L/S                                         2.65 L/S                                                           6.63 L/S

DHW7001410 – 877.8 KW    4.23 L/S                                         2.84 L/S                                                           7.07 L/S

Domestic Hot Water (DHW) Plate Heat Exchangers can be supplied as a Plate / Gasket unit or supplied as a Brazed Plate unit

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All AEL Plate Heat Exchangers are designed to instantaneously supply the required flow of water and most other fluids at a pre determined set point temperature within a 1 or 2 degree tolerance for your project.

Should the system design change in future the plate and gasket plate pack can be redesigned by removing, adding or changing the plate pack within the frame.

The brazed plate heat exchanger plates are a fixed design that can only be changed by increasing or decreasing the flow rate, temperature on either Primary or Secondary circuits or by increasing or decreasing the Primary KW input but not by changing the plates.

DOMESTIC HOT WATER (DHW) PLATE HEAT EXCHANGERS

Domestic Hot Water (DHW) Plate Heat Exchangers can be supplied as a Plate / Gasket unit or supplied as a Brazed Plate unit. In practice both types of heat exchanger transfers energy from hot or cold fluid and ensures that the Primary circuit does not mix with the Secondary circuit therefore creating two completely independent separate heating or cooling circuits.

When close control is required in a system that has limited temperature control it is common practice to install an AEL Packaged Plate Heat Exchanger with integral controls in a DHW application as the temperature needs to be controlled properly so as not to scald anybody using a tap or shower.

USING PLATE HEAT EXCHANGERS AS A CENTRAL HEATING SYSTEM BREAK

Using an AEL Plate heat exchanger as a central heating system break to protect an expensive piece of equipment such as a Boiler or Chiller is a very common practice.

AEL Plate Heat Exchangers are used in these applications to separate the Central Heating system into two circuits, one Primary circuit dedicated to the boiler which in turn heats up the Secondary circuit that feeds the radiators and associated heating or cooling equipment.

The general idea of the Central Heating System Break is to separate the heating into two circuits so that any deposits floating around an old heating system will not damage or shorten the life of the expensive boiler & associated equipment .

FULLY CONTROLLED PACKAGED PLATE HEAT EXCHANGERS

Systems requiring an AEL Packaged Plate Heat Exchangers usually require very close temperature control. These units are skid mounted and can be fully or partially controlled c/w control panel, pumps, diverting valves and control thermostats.

Applications – usually used for Domestic Hot Water (DHW), Swimming Pools (SP) or can be a Bespoke Plate Heat Exchanger specifically designed for ypur application.

BRAZED PLATE HEAT EXCHANGERS

Brazed plate heat exchangers are very compact and can operate in pressures exceeding 30 bar.

Brazed Plate Heat Exchangers do not have bolts or frame so they cannot be opened up for any necessary cleaning which will need to be done by circulating chemicals around the plates.

The number of plates on a Brazed plate heat exchanger plates are fixed which means that the design duty can only be changed by increasing or decreasing the flow rate, temperature or primary KW input.

PLATE AND GASKET HEAT EXCHANGERS

The advantage that a Plate and Gasket type heat exchanger has over a Brazed type is that they do come with bolts within a frame and can be opened for servicing / cleaning or to alter the number of plates to change the performance / duty at a later date by increasing or decreasing the flow rate, temperature or primary KW input.

Plate and gasket heat exchangers are suitable as Central Heating System Breaks, direct Domestic Hot Water (DHW) supply, Swimming Pools and most other applications.

SWIMMING POOL PLATE HEAT EXCHANGERS

AEL Swimming Pool Plate Heat Exchangers must be robust and purpose made to cope with the corrosive atmosphere and water in a swimming pool environment.

The AEL  fully controlled packaged Swimming Pool Plate Heat Exchangers tend to be most popular with medium to larger new build pools. Whilst the Bare Plate Heat Exchangers (excluding controls) are also popular with new build but they are more popular as replacements for older equipment that have failed as they can easily be incorporated into an existing system to operate within the design of the existing pumps and controls.

Most Plate Heat Exchanger Designs for Central Heating, Domestic Hot Water and Swimming Pools tend to be the same or very similar 90% of the time so with this in mind AEL have provided all the cost prices and technical information required for each application from 30KW up to 1000KW as a standard design so that they can be viewed and purchased online.

AEL Plate Heat Exchangers have been used to heat and cool many types of fluids in the UK for over 35 years and they all operate the same way in principle whether assembled as a Plate and Gasket unit, Brazed or supplied as a Shell and Tube unit.

In practice all three types of heat exchanger transfers energy from a hot or cold fluid and ensures that they do not mix by creating two completely independent separate heating or cooling circuits.

Please see the link below and feel free to send over any questions or enquiries you may have.

NON STANDARD HEAT EXCHANGER BESPOKE PHE ENQUIRY

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AEL supply Alfa Laval AHRI approved Plate Heat Exchangers, AHRI is a globally recognized and industry respected third party certification program that allows you the customer to differentiate between suppliers and provides the assurance and peace of mind that you are purchasing a plate heat exchanger of the highest quality.

When specifying  Engineers and other decision makers purchase an Alfa Laval Plate Heat Exchanger that bears the AHRI Certified^® mark, it will provide them with the added assurance that the equipment that they have purchased is manufactured using materials of the highest quality and that it will perform accurately and consistently in line with the design provided by AEL at quotation stage.

AEL Plate Heat Exchangers are used to either heat up or cool down many different types of fluid. When heating up a fluid such as water the Primary heat source from a boiler or waste water heat recovery system will transfer the heat energy from the Primary side to the cold Secondary side that requires heating instantaneously to a set point temperature making sure that the two circuits are kept separate.

AEL Plate heat exchangers are often used as system breaks in HVAC circuits in old systems offering protection to the boiler or fitted into new systems that prolong the life of a boiler by many years. Plate heat exchangers tend to be compact in size and fit nicely between boilers and other equipment such as pump sets and pressurization units.

The main advantages of using an AEL plate heat exchanger are:

• Compact design
• High thermal efficiency
• Easy to service.
• The duty / performance can be altered by decreasing or increasing the number of plates required.
• Suitable for Commercial and Industrial applications
• Suitable for use with water, steam and many other mediums.
• No storage and instantaneous heat up which eliminates the environment that breeds legionella bacteria.
• No standing heat losses as the water content is minimal and no storage is required.

Typical Commercial and Industrial applications where AEL plate heat exchangers have been used:

• Boiler circuit system breaks
• Swimming pool system break from Central Heating circuit.
• Renewable energy installations such as Heat pumps
• Food & Dairy process for milk pasteurising, milk cooling and general hygienic cleaning purposes.
• Heating and cooling of liquids in industrial process plants.
• Pharmaceutical Industry providing hygienic water heating and cooling
• Heating and cooling of chemicals.
• Heating, Ventilating and Air Conditioning
• Marine Environment for engine cooling, oil cooling, intercoolers and general cleaning purposes.
• Brewing process plant for cooling and conditioning fluids.

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HOW TO USE THE AEL PLATE HEAT EXCHANGER SIZING CALCULATOR

1. Go to www.aelheatexchangers.co.uk home page and select the type of installation that best suits your project.
2. Once you have selected the type of installation you then “select the model or type of Alfa Laval Plate Heat Exchanger” you require.
3. When you have selected your preferred type or model of heat Exchanger you then only need to “type in the KW power” that your project requires ( Temp Rise x 4.2 x Flow Rate l/s = KW ).
4.  When the KW power required has been selected the page will automatically refresh and re calculate the technical duty information and price on the page for you to use for your specification or to purchase.
5. If the duty shown is not quite what you required then all you need to do is increase or decrease the KW input to automatically alter the duty.

NOTE: Altering the KW required will change the duties for each type of installation shown in the filter apart from the “Swimming Pool” heat exchangers where the pool volume is changed instead of the KW.

The principle that heat will always leave the warmer fluid and that heat energy will be transferred to the colder fluid must be understood when working with Plate Heat Exchangers.

With any plate type heat exchanger, the heat will instantaneously pass through the plates that separates the hot and cold fluid heating up the colder fluid.

Heat will always be transferred from a hot medium to a cold medium and there must always be a temperature difference between the fluids. The heat lost by the hot fluid will be equal to the amount of heat gained by the cold fluid except for standing thermal losses that are usually minimal.

AEL have already standardized a large selection of Heat Exchanger duties for:

• Domestic Hot Water (DHW) Plate Heat Exchanger sizing calculator.
• Central Heating System Break Plate Heat Exchanger sizing calculator.
• Swimming Pool Plate Heat Exchanger sizing calculator.
• Wall Mounted Substations Plate Heat Exchanger sizing calculator. .

Contact AEL If you have a technical question at sales@aelheatexchangersuk.co.uk

The post ALFA LAVAL PLATE HEAT EXCHANGER SIZING CALCULATOR WITH PRICES appeared first on AEL Heat Exchangers.

If you would like immediate access to all the prices and technical information of an Alfa Laval Plate Heat Exchanger and know the KW output of the Plate Heat Exchanger you require you will find everything you need to complete your tender at www.aelheatexchangers.co.uk .

If  you do not know the KW output required of your project then just use this easy formula : Temp rise x 4.2 x  flow rate l/s  = KW

Most designs for Central Heating, Domestic Hot Water, Swimming Pools and some Renewable energy applications can tend to be the same or very similar 90% of the time so with this in mind AEL have published standard designs for all these applications on our website www.aelheatexchangers.co.uk  .

Each “easy to view” design instantly provides you with all the  technical information you require with prices for quick budget purposes, design indicators or for straight forward purchasing.

AEL will provide you with full technical support for all of our products by phone and e mail sales@aelheatexchangers.co.uk when we will be more than happy to discuss your installation requirements and whether a plate heat exchanger may or may not be suitable for your current project.

TYPICAL HEATING SYSTEM

TYPICAL DHW SYSTEM

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Basically a shell and tube heat exchanger has a cylindrical shell with a tube bundle in the center. The high thermally efficient tube bundle allows heat to be exchanged between the hot fluids flowing outside the tubes and the cooler fluid ( e.g pool water) flowing through the tubes.

NOTE: LOCATION OF FLOW AND RETURN CONNECTIONS CAN VARY WITH EACH MODEL.

Shell and tube heat exchangers are usually used in applications that require cooling or heating large volume of process fluids with minimal pressure loss even though this can quite often still be achieved with a Plate Heat Exchanger.

There is a choice of different types of shell and tube heat exchanger designed to suit different applications in most industries.

The Construction of a Shell and Tube Heat Exchangers
The following four components are the main parts of a shell and tube heat exchanger:

1. Tube Bundle: A tube bundle that comprises of tube sheets and tubes.
2. Shell: The tube bundle is fitted inside the outer shell.
3. Return Header: is the part of the heat exchanger where the cooler return fluid enters the heat exchanger.
4. Return Header:is the part from where the hot or heated fluid flows from the heat exchanger.

Materials Used for Shell and Tube Heat Exchangers
Materials Used for Shell and Tube Heat Exchangers

• Cupronickel Alloys
• Titanium
• Carbon Steel
• Brass Alloys
• Stainless Steel

What Are the Benefits of Using Shell and Tube Heat Exchangers
AEL Shell and tube heat exchangers are popular in a number of industries because:

• They have more heat transfer efficiency than most other heat exchangers.
• They are perfect for corrosive applications such as swimming pool heating and salt water.
• They can be easily cleaned.
• They are compact in size.
• They can be banked to increase capacity /output.
• They give a great return on investment because they give long term efficient service and are affordable compared to other heat exchangers.
• Pressure testing is simple.
• They are perfect for systems that operate at high operating pressure and temperatures.

The post WHAT ARE SHELL AND TUBE HEAT EXCHANGERS appeared first on AEL Heat Exchangers.

RECTANGULAR & SQUARE POOLS

Enter Dimensions of your pool;-

Length (L) ……………………Metres
Width (W)…………………… Metres
Min Depth (D1)…………….. Metres
Max Depth (D2)……………. Metres

1. If the pool has a flat bottom, enter the same figure for max and min depth.

If your pool has a sloping bottom, then take the deepest measurement (D2) and the shallowest (D1).

CIRCULAR POOLS

Circle Diameter………………. Metres
Min Depth (D1) ……………… Metres
Max Depth (D2)……………… Metres  Calculate

If the pool has a flat bottom, enter the same figure for max and min depth

ELLIPSES SHAPED POOL (A closed, symmetric curve shaped like an oval)

Enter Dimensions of your pool;-

Main Diameter (A)…………………… Metres
Minor Diameter (B)……………………Metres
Min Depth (D1)………………………. Metres
Max Depth (D2)……………………… Metres

1. If your pool has a sloping bottom, then take the deepest measurement (D2) and the shallowest (D1). If there are different levels, then you need to do several calculations of area for each depth and add them up at the end.

2. If the pool has a flat bottom, enter the same figure for max and min depth.

IRREGULAR SHAPED POOLS

For irregular shaped pools, calculating the area is less accurate so stay on the side of safety. You will need to draw up the pool accurately to scale on graph paper using a square on the paper to represent a meter square of pool.

When you have finished, counting the squares, count anything over half as one square and anything under as half. When you have the area (A) multiply by depth (D) for the Volume in cubic metres.

1. If the pool has a flat bottom, enter the same figure for max and min depth.

2. If you have several depths, break up your area calculation for each depth.

Enter Dimensions of your pool;-

Area (A)…………… Metres
Depth (D)…………..Metres

The post HOW TO CALCULATE THE VOLUME OF WATER IN A SWIMMING POOL – PLATE HEAT EXCHANGERS appeared first on AEL Heat Exchangers.

Firstly, in order to identify Legionnaires disease as a significant hazard it is important to know and understand the factors that affect the rate of growth and transmission of legionella as well as any potential exposure to the hazard.

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 typical 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 stainless steel with a corrugated profile which 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.

The post USING A PLATE HEAT EXCHANGER TO REDUCE THE RISK OF LEGIONNAIRES DISEASE appeared first on AEL Heat Exchangers.

AEL have been supplying brazed plate heat exchangers for use in many applications throughout the UK , Ireland and the Channel Islands since 1972.

Alfa Laval Brazed plate heat exchangers are compact in size and are a highly efficient method of providing instantaneous heat transfer between fluids in a heating system.

Using Brazed plates with Heat Pumps is an extremely cost-effective way of utilising every Watt of energy generated from a heat pump to provide a highly efficient heating system. They are maintenance free and provide long term service.

Brazed plate heat exchangers are used in a range of applications such as cooling, heating, evaporation, condensing and of course renewable energy which includes Heat Pumps.

Please view our standard Alfa Laval Brazed Plate Heat Exchanger units on www.aelheatexchangers.co.uk which are built and tested to perform for many years at optimum efficiency and pressures up to 32 bar.

To view all the Alfa Laval Brazed Plate Heat Exchangers please visit www.aelheatexchangers.co.uk

The post ALFA LAVAL BRAZED PLATE HEAT EXCHANGERS SUITABLE FOR HEAT PUMPS appeared first on AEL Heat Exchangers.

1. Plate Heat Exchanger
 To start, we need to know the KW required to meet the demand from the central heating circuit to start calculating the most suitable PHE

2. System Control Panel
 The control panel will sense the secondary flow temperature leaving the plate heat exchanger and send a signal to the modulating 3 or 4 port valve to close or open depending on demand

3. Primary
 3 or 4 port valve This valve will open or close as demand (temperature) increases or decreases on the secondary flow out of the PHE

4. Primary
Heating Pump This pump will circulate water at the correct design flow rate

5. Secondary
 Radiator Circuit These can be radiators or any heat emitters including underfloor heating

6. Secondary
 Cold Feed & Mains Kit This is the point where fresh water enters the heating circuit to replenish lost water

7. Secondary
 Heating Pump This pump maintains the correct flow between the cylinder & PHE

8. Secondary
 Temperature Sensor This will sense the DHW flow temperature out of the PHE to the outlets and tell the control panel to open or close the 3 or 4 port valve allowing more or less hot water through on the Primary side of the PHE

9. Secondary
 Non Return Valve This will stop fresh water from going backwards into the heating circuit

10. Boiler or Primary heat source
This can be a boiler or any heat source that can generate the KW required to boost the secondary heating circuit

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