Harnessing Free Heat. The Energy Harness provides hot water using multiple heat sources, making the best use of low grade heat. It improves the efficiency.

Harnessing Free Heat

The Energy Harness provides hot water using multiple heat sources, making the best use of low grade heat.

It improves the efficiency of gas boilers by storing heat reclaimed from flue gases, and using this to pre-heat domestic hot water.

Design Objectives

Increase efficiency of gas boilers.

Make best use of renewable heat. Solar

Biomass

Heat Pumps

Simple to Install

Reliable, maintenance free operation.

Meeting the Needs

• Provides instantaneous mains pressure hot water at all times.

• No user interaction required.• Overcomes Legionella risks.• Maximises gain from free energy sources.• Minimises use of gas, thereby reducing

running costs.

Meeting the Needs

• Provides instantaneous mains pressure hot water at all times.

The EnergyHarness will ensure that there is always hot water to taps. Once all stored heat has been used up the system automatically switches to instantaneous mode, heating water as required via the gas boiler.

Meeting the Needs

• No user interaction required.

Many systems require the end user to time the use of the gas boiler to meet hot water demand. This can often be a cause of inefficiencies as time clocks are left on longer than required, wasting gas by heating water that could otherwise have been heated for free.

The EnergyHarness does not used the boiler to heat the cylinder, and there are no settings for the user to get wrong.

Meeting the Needs

• Overcomes Legionella risks.

It is generally recommended to store domestic hot water at over 60°C to kill off Legionella bacteria. The stored water in the EnergyHarness never changes and does not feed taps. Instead, domestic hot water is heated as it is used. There is no danger of Legionella, even with the stored water remaining at low temperatures for extended periods.

Meeting the Needs

• Maximises gain from free energy sources.

The entire storage volume of the EnergyHarness is dedicated to storing free heat.

The ability of the system to safely store heat at up to 80°C ensures that solar panels can run longer in sunny conditions, and store more energy before reaching overheat.

Meeting the Needs

• Minimises use of gas, thereby reducing running costs.

The domestic hot water is pre-heated by the EnergyHarness, and the gas boiler is only used to top-up domestic hot water temperature when needed.

If there is enough heat in the EnergyHarness to supply taps, then the boiler will not fire.

The basic principles of a Heat Bank...

A store of hot water connected to a feed tank.

Feed Tank

Cold Feed

Heat Bank

Vent

The tank fills the Heat Bank with water.

It also takes up expansion and contraction as the system heats up and cools down.

Once filled, the water never changes, and any evaporation losses are topped up automatically.

The water in the Heat Bank DOES NOT feed taps.

Taps are fed directly from the mains through a plate heat exchanger.

Domestic hot water is generated using a plate heat exchanger.

Mains water, at high pressure, flows through one side of the plate heat exchanger.

Store hot water, at low pressure, is pumped through the other side of the heat exchanger, heating the mains water.

1. A tap is opened.2. The flow switch detects

the flow and turns on the pump.

3. The pump circulates hot stored water to the plate, heating the mains.

4. A mixing valve mixes the hot with some cold to obtain the desired supply temperature to taps.

5. When the taps is turned off, the flow switch turns off the pump.

Operation…

The standard plate heat exchanger can generate 160kW of hot water this way, equivalent to 45 litres per minute, or three outlets running at once.

The EnergyHarness, as standard, captures low grade heat recovered from boiler flue gases. The heat is stored and is used to pre-heat mains water.

The pre-heated water is then supplied to taps, or if the temperature is too low, the water is diverted via the combination boiler to be topped up.

The water in the Heat Bank can be

used to feed radiators.

Underfloor Heating can also be fed

from the Heat Bank.

Central heating can be fed using ANY heat source connected to the

Heat Bank.

• Gas or Oil Boilers• Wood Burners and Biomass Boilers.• Solar Panels.• Heat Pumps.• Heat Recovery Systems.• Immersion Heaters (Electric)

The Heat Bank is designed to work in conjunction with any (or all) heat sources, including…

• Boilers connect directly to the Heat Bank, without the need for a coil.

• A mixing valve is used to assist recovery.

1. Initially, water is pumped from the top of the Heat Bank to the boiler for heating, and then back to the top of the Heat Bank.

2. Once the top of the store is heated fully, the mixer valve starts to draw cold from lower down the Heat Bank.

3. The Heat Banks heats from the top-downwards until fully recovered.

Boilers…

The advantages to this method of heating are as follows…

• Heats small amounts of water very quickly, providing hot water to taps within minutes of turning on.

• The boiler fires at full output, and remains in condensing mode, at all times.

• The amount of water heated up can be varied, either by timing the period the boiler fires, or by using multiple thermostats to turn off the boiler.

Boilers…

Wood Burners…

Wood burners connect directly to the Heat Bank without using a coil. The simplest connection method uses the principle of thermo-siphon, with hot water rising from the wood burner into the Heat Bank as cold water drops from the bottom of the Heat Bank to the wood burner.

Wood Burners…

Overheat protection can be easily provided by turning on the central heating automatically once the Heat Bank reaches 90°C.

Wood Burners…

Power-free overheat protection can also be provided by passing cold water through a coil in the top of the Heat Bank, once the water reaches 94°C.

The coil can be retro-fitted, and a thermostatic valve on the mains water feed is fitted to regulate operation.

Solar Panels…

Heat Banks are usually fitted with a coil for connection of solar panels.

A coil is used so that the solar circuit can be filled with anti-freeze and pressurised.

Solar Panels…

As Heat Banks can be heated up to 90°C without any problems, they allow more solar heat to be stored before overheat protection comes into play.

Any excess solar heat can also be used for central heating!

Heat Pumps…

Heat Pumps are connected directly into the Heat Bank.

Most heat pumps only generate water up to 55°C, and are typically connected to the bottom half of the Heat Bank, while high temperature heat sources connect to the upper half.

Heat Pumps…

Due to the lower running temperatures, heat pumps are usually used in conjunction with underfloor heating.

This is also fed from the bottom half of the Heat Bank.

Heat Recovery…

Heat recovery system such as the HotBox are treated like heat pumps, and connect directly into the lower half of the Heat Bank.

Again they are often used in conjunction with underfloor heating.

Immersion Heaters…

The simplest method heating the Heat Bank is electrically, using fitted immersion heaters.

These can be either 3, 6, 9 or 12kW, and it is possible to fit up to three in a standard Heat Bank.

Immersion heaters provide a perfect backup to other heat sources.

3 Possible Positions

It is possible with the Heat Bank to combine

any, or all, of these heat sources to provide hot water and heating….

• Laser cut and laser welded Duplex stainless steel construction.

• 40mm Insulation with attractive chrome finish casing.

• Tested to 9 bar pressure.• Finned 1m2 solar coil.• 3 x 2¼” bosses for heaters.• 2 x 1½” bosses for wood burners. • 22 x ¾” bosses for anything else.• Lifetime guarantee.• 1 Year on-site backup.

The standard Heat Bank …

• Pumps.• Control Valves.• Thermostats.• Programmers.• Factory Wiring.• Heat Exchanger Assembles. • Immersion Heaters.• Custom Systems.

Options for all occasions …

The only system approved by most wood burner manufacturers…

The only system that can do everything.

Xcel Heat Banks