Boilers with wide modulation ratios can improve efficiencies and comfort while reducing wear and tear on components - but what does the term mean, and how can installers explain it, and its benefits, to end users?  Here Alister Maclachlan, product director at Vokèra, provides some advice following the launch of Vokèra’s Linea One boiler that boasts a modulation ratio of 10 : 1. 

In recent years some boiler manufactures have started to talk about modulation ratios - but what does the term mean and, more importantly, how does the end user benefit?

In simple terms, the modulation ratio is a boiler’s ability to reduce its maximum output to its minimum output.  A narrow modulation range gives a poor ratio whereas a wide range provides a good ratio.  For example, if a boiler has a maximum output of 30kW and a minimum output of 7.7kW its modulation ratio is less than 4:1.  Meanwhile, a boiler with a maximum output of 30kW and a minimum output of 3kW has a wider (hence better) modulation ratio of 10:1.  As a general rule, for a boiler to be classed as having a ‘good’ modulation ratio its minimum output should be one fifth or one sixth of its maximum output. 

High Modulation Ratio Ignition Sequence

Low Modulation Ratio Ignition Sequence

There are two important reasons why a good boiler modulation ratio is preferable - and understanding these reasons can help installers explain the benefits to end users.

Firstly, a good boiler modulation ratio reduces constant on/off cycling, improving efficiency and boiler longevity.  For example, if a boiler has a high maximum output - let’s say 40kW - yet only has a modulation ratio of 4:1 it will only be able to modulate down to 10kW.  However, when most rooms have reached the required temperature and radiator TRVs have closed, the demand on the boiler will be considerably less than 10kW.  This means that the minimum output of the boiler will be higher than it needs to be, so the boiler will constantly switch on and off - leading to fuel inefficiency and unnecessary wear and tear on its components and parts. 

A boiler with a high maximum output and a good modulation ratio, however, will be able to modulate down to an extremely low output, reducing wear and tear on primary components (fewer on/off cycles increase component longevity) and optimising fuel efficiency.

The second reason is uniquely associated with combi boilers, as it concerns the stability of domestic hot water (DHW).  A boiler with a poor modulation ratio won’t be able to maintain a stable DHW flow temperature at a low flow rate, and might even cause the burner to switch off during operation.  This can be a significant issue for end users who prefer showers over baths or for those who require a constant DHW outlet temperature - for example where there are young children or elderly people in a household, who are at a higher risk of scalding. 

So when selecting a combi boiler it’s crucial to consider modulation ratios - and to remember that performance isn’t just about kW output.  Nowadays 40kW combis are commonplace, having been introduced to improve hot water flow rates; in the 1980s a typical combi boiler had an output of 24kW (80,000BTUs) and a DHW flow rate of around 9.5l/pm at a 35^oC differential, leading to end user gripes about hot water performance.  However, installing a combi boiler with a high maximum output and a poor modulation ratio in a typical UK property is unlikely to deliver optimal efficiency, or comfort. 

Let’s take a three-bedroom semi-detached house, built in the 1960s, as an example.  This type of dwelling will probably only need a maximum of 15kW for space heating, and significantly less when it has reached temperature, especially if the property is insulated and has heating controls fitted.  Hence a 40kW combi boiler that can only modulate down to 10kW isn’t good news for the customer either in the short or long term; as well as resulting in DHW instability and temperature fluctuations it will be unable to deliver fuel economy (the end user will of course be expecting their new boiler to deliver savings), and will probably suffer from early component failure.

Installers have a key role to play in ensuring that UK heating systems become more efficient, and end users will very often turn to them for advice.  We believe that an increasing number of astute installers are beginning to recognise that if a boiler can boast a wide modulation ratio it will deliver significant benefits.  It is however important to demonstrate this to customers, as it could help them in their decision making process.  Manufacturers should be able to assist by providing diagrams and literature, which can help to explain the concept - and benefits - in a simple, easy-to-understand way.

Vokèra has made a significant investment in the development of boilers with excellent modulation ratios.  Our Linea One 38kW combi boiler boasts a class-leading 10:1 modulation ratio, enabling it to modulate its output to 10 per cent of its maximum - 38kW down to 3.8kW. 

Good modulation ratios offer a range of benefits - including increased fuel efficiency, end user comfort and boiler longevity.   

For more information about the Vokèra Linea One boiler, click here

Vokèra Verve

Vokèra launches high power system boiler

Vokèra is pleased to announce its latest product launch, a new large domestic and light commercial system boiler Verve.  The 47kW high-power boiler is designed to offer installers a solution for both large domestic and light commercial boiler applications.

Adding to Vokèra’s comprehensive range of boilers, the Verve offers a 90 per cent efficiency rating and can lead to reduced running costs of up to 35 per cent – making it one of the greenest high-power domestic boilers on the market.

Installers will find both the electronic regulation functions and heat engine design very familiar, being similar to those used on standard domestic boilers.  The unit itself is also relatively lightweight weighing in at just 39 kilograms, meaning the Verve is easy to handle and easier to fit. 

Alister Maclachlan, product director at Vokèra, comments: “We chose to launch the Verve as it offers installers the option to install a high power system boiler that is familiar in design to that of our domestic range, enabling them to expand their scope of work into larger domestic properties or small commercial premises.

The Verve boiler is supplied with an 80+80mm flue configuration enabling the flue to run up to 20m, or the flue can be re-configured with an optional flue adaptor to a 60/100mm or 80/125mm flue configuration. The Verve is supplied with isolating valves, enabling the boiler to be isolated from the system, which is extremely useful on larger systems, where to drain and refill the system could take several hours. 

Vokèra also offer a range of options to accompany the Verve, including the highly recommended hydraulic separator, which ensures the appliance is isolated from any changes in the hydraulic flow rate.  Also available is the three port valve which helps to speed up installation.

For more information on the Verve boiler click here

Increases in domestic gas prices mean we will all be feeling the pinch on household budgets more than ever this winter.  Alister Maclachlan, product director at Vokèra, looks at how the latest advanced controls can significantly improve the efficiency of a heating system and reduce utility bills - without requiring too much of a financial outlay.

Following the announcement that energy prices are set to rise even further, many homeowners will be looking to reduce their energy usage to combat the price hikes.  The Government’s RHI (Renewable Heat Incentive) and Green Deal schemes are designed to help homeowners afford energy saving measures - but aren’t going to provide immediate assistance.

Though the RHI Renewable Heat Premium Payments are now available, providing a one-off payment if a homeowner has a renewable technology installed (depending on the technology and if certain criteria is met), the ongoing tariffs will not be available until late 2012. 

Similarly, the Green Deal will not be up and running until the end of 2012 at the earliest.  This new scheme will see major energy suppliers offering loans to homeowners who want to install energy efficient measures and technologies. 

So, with help from the RHI and Green Deal being some way off, how can installers help homeowners to find a cost-effective way to be more efficient?  There is clearly a need for an immediate, affordable solution - and this is where the latest intelligent heating and hot water controls really come into their own. 

Thermostats and controls have been on the market for many years and are an essential part of a modern central heating system; however, more recently manufacturers have invested heavily in further advancing boiler control technology to improve the efficiency of the boiler.  In fact, the latest generation of controls offer homeowners even greater command over their heating and fuel usage, and when teamed with a high efficiency boiler, can dramatically reduce fuel bills for the end user.

The very latest innovation to hit the market is built-in OpenTherm technology.  It’s estimated that up to 10 per cent of the energy consumed for space heating can be saved by using this type of control with an appropriate HE boiler.  Fuel efficiency can be maximised by specifying these controls alongside boilers with higher modulation ratios, for example ratios of 5:1 and higher. For customers looking to reduce their fuel consumption immediately, OpenTherm could be an ideal solution, and is suitable for retrofit as well as new installations (depending on the boilers compatibility with OpenTherm protocol).

The benefit of OpenTherm technology lies in its ability to regulate the temperature of the room more effectively than a standard room thermostat.  When a standard ON/OFF room temperature/programmable room thermostat is used, the boiler will usually provide a flow temperature that’s much higher than required for the room to reach the temperature set by the thermostat.  This causes the boiler to ‘overshoot’, and as a result the home will actually become too hot.  To compensate, the boiler switches off, and the temperature drops again.  When the temperature goes below the set-point (the nature of traditional thermostatic controls means a boiler will ‘undershoot’), the boiler turns back on - and so this pattern continues.  This frequent ON/OFF cycling results in an inefficient use of fuel and unnecessary wear and tear on boiler parts. 

OpenTherm protocol controls are also available as wireless (RF) units, making them particularly suitable for retrofit applications.  Vokèra is one of the few manufacturers to offer this type of control in a wireless format.  Wireless OpenTherm controls provide a neat installation, something that is particularly ideal for house-proud customers who are concerned about the aesthetics of their home, and are easy to fit.  With a 30 metre wireless transmitter, both new and retrofit installations are quick, simple and tidy.

Another recent development in controls has been weather compensation technology, which regulates the output of the boiler in line with the outside temperature, and is particularly effective when unseasonal weather occurs.  Using weather compensation will almost always ensure that the boiler is fully condensing and this maximises fuel efficiency.  In fact, under the proposed SAP 2009, the installation of a weather compensation control can increase the efficiency of a condensing boiler by up to 3%, enabling efficiencies in excess of 93 per cent.  A weather compensation control not only saves energy, it can also ensure a more comfortable environment inside the home too.

While a selection of boilers are being supplied with weather compensation controls included, a key benefit is that existing boilers can be upgraded to include this technology.  If fitting an external weather sensor, it is advisable to fit the controls to a north or north-west facing wall to achieve optimum results. 

Both OpenTherm and weather compensation controls offer an affordable, cost-effective way to improve energy efficiency - and could provide a useful stop-gap until other measures, such as a more efficient boiler or a renewable technology, can be fitted. 

When specifying controls it’s worthwhile looking for any additional features that will add to the usability of the control, ensuring the homeowner can make the most of their heating system, manage their energy efficiently and maximise comfort.  For example, the OpenTherm protocol RF control from Vokèra includes a handy holiday function.  This allows the end-user to set the control for the duration of the holiday, and the temperature at which the boiler should operate at during this period and for when they return.

If a control boasts an optimisation function, this means it will start the boiler working before the programmed ‘ON’ time, so the desired temperature is reached for when the homeowner wants it.  Some controls also give homeowners access to useful information too, such as the current and target room temperatures. 

When specifying controls with advanced user functions, it is important to ensure the homeowner is properly briefed when the unit is installed.  This will ensure the customer knows how to operate the controls and that the maximum energy savings can be achieved.   

With fuel prices rising dramatically and the effects of the economic downturn still being felt, there has never been a more important time to ensure a home’s central heating system runs as effectively and efficiently as possible.  Installers can provide valuable information to homeowners about the advantages of intelligent controls to help them reduce their energy usage now, so they are better prepared to manage the cost of their utility bills in the future.

Our website has a wealth of information on boilers, controls and renewables, to help you save on your fuel bills

Renewable Heat Premium Payment Grant finally announced

If you are installing renewables, then you need to read on, the Government Renewable Heat Premium Payments (RHPP) have finally been announced and will be availale from 1st August 2011.

What is great about the RHPP is that so far the scheme seems to be very simple.  This will help its success - something we saw with the boiler scrappage scheme, which was kept very clear and subsequently worked very well.

The premium payments demonstrate that the Government is backing renewable technologies and recognising their importance in meeting our carbon reduction commitments

The announcement from the DECC on 21st July 2011 has confirmed the scheme will start on 1 August.  Installers who have not started need to get prepared.  Vokèra’s advice to installers is to get MCS accredited, finish off any necessary training so they can offer these additional services to their customers alongside their core business.

The RHI (Renewable Heat Incentive) tariffs which are expected to launch in October 2012, will further encourage their uptake.  We are expecting announcements regarding the criteria and amount of ongoing tariffs for households who invest in the eligible renewable heating technologies later this year.  

Vokèra is urging the Government to announce the RHI tariff criteria as soon as possible.  The ideal situation would be that the criteria is the same for the tariff as it is for the RHI Premium Payment, so people are assured of this continued support.  Alternatively, the Government should allow homeowners who do not meet the criteria a chance to implement any necessary changes and reapply.

RHPP Factfile

What is the RHPP?

The Renewable Heat Premium Payment scheme is a Government scheme that gives householders a one-off payment to help them buy renewable heating technologies - solar thermal panels, heat pumps and biomass boilers.  It will run between 1 August 2011 and 31 March 2012.  It only runs for eight months - because from October 2012, the Renewable Heat Incentive tariffs will be launched for the domestic sector and the Green Deal will come into force.    

What is the criteria?

Where practical, loft insulation to a minimum of 250mm and cavity wall insulation needs to be in place.  The products installed and the installer must be MCS (Microgeneration Certification Scheme) approved.

Following installation the homeowner will complete two surveys and could have the opportunity to have a free meter installed to monitor the energy performance.

How much is it worth?

ALL HOUSES

£300 - Solar thermal -voucher valid for 3 months

HOUSES NOT HEATED BY GAS FROM THE GRID

£850 - Air source heat pump - voucher valid for 5 months

£950 - Biomass boiler -voucher valid for 6 months

£1250 - Ground source heat pump -voucher valid for 6 months

How do you apply?

Apply online at the Energy Saving Trust website.  If the criteria is met, a voucher will be issued, which must be returned before its expiry date with a copy of the invoice and certificate from the MCS. 

The Scheme will end on the 31 March 2012, or when the allocated funding has been issued.

So, how do we access the RHI tariffs?

Installations that have received the RHPP will be eligible for the RHI tariffs, providing you meet the RHI criteria, which has not yet been finalised.  Full details of the scheme and eligibility can be found on the EST website: www.est.org.uk

Vokèra has announced the launch of the new Linea One, a SEDBUK A rated combi boiler, with high output of 38kW and excellent domestic hot water performance of 15.6 litres per minute.

Linea One is our flagship combi boiler, boasting an array of exceptional features, benefits and efficiency for maximum end user comfort as well as offering a 5 year parts and labour guarantee as standard for total peace of mind.

The Linea One has one of the lowest NOx emissions in its class, with just 29mg/kWh and has an outside weather sensor included in the box, enabling it to be up to 93% efficient*

Alister Maclachlan, technical director, for Vokèra, said:  “We’re really excited about the new Linea One, as we believe it offers customers a high quality, high performance, modern boiler which features some of the latest technology in energy efficiency.”

A snapshot of Linea One’s functions:

Intelligent ‘Pre Heat Memory’ function

The Linea One incorporates an intelligent domestic hot water ‘Pre Heat Memory’ function that, when selected, adapts the appliance pre-heat function to match your typical daily hot water usage pattern. Over a 1-week period, the boiler monitors at what times and how much hot water your household uses, thereafter the pre-heat function of the boiler is automatically adapted to suit your lifestyle, ensuring that there is always an immediate supply of hot water when you need it.

‘Comfort’ function

The ‘Comfort’ function allows you to set a fixed outlet temperature for DHW within the range 35°C to 45°C (factory set at 40°C).  By choosing to operate this function you ensure that your DHW is of a comfortable and safe temperature which is especially useful if there are young children or elderly relatives in the home.

To find out more email marketing@vokera.co.uk

*Based on SAP 2009

You could get up to £520 funding available for Fuel Switching from A1 LCS!

Do you have electric or coal heating and want to change to a gas, oil or LPG heating system?

Then grant funding is available to you through your heating installer if you are having a new gas, or LPG A-rated Vokèra (other boiler manufacturer models are also available) boiler with an efficiency of 90% or more purchased from Plumb Center, fitted where you have previously had electric or coal fired heating.  This is known as fuel switching. This funding comes from npower to encourage home owners to switch their current electric or solid fuel heating to a cleaner gas or oil system. This means that less carbon dioxide is being released into the atmosphere and therefore improving energy efficiency.

The A1 LCS (Low Carbon Solutions) grant funding devised by npower as part of their energy efficiency commitment is operated through a nationwide base of over 10,000 registered installers. All installers on the scheme have access to specific products and a wide knowledge base of high efficiency products and renewable technologies.

How much could I get? 

Fuel switching relates to the changing of the primary heating fuel of your home. The primary heating fuel is the fuel which is used to heat your main living area such as your lounge or living room. For example if your house has a gas fire in the living area and electric storage heaters in the bedrooms it would be considered a gas heated home. If the living area has a focal point fire of any fuel and electric storage heaters it would be considered an electrically heated home. If your primary heating fuel is either electric or coal and you are changing to more carbon friendly gas or oil alternative this is considered to be a fuel switch and you will be entitled to grant funding.

Grant funding available for fuel switching is determined by both your existing heating and the heating type which you have installed. The standard level of funding applies to all privately owned domestic properties and the higher level of funding is available to those customers who are aged 70 or above or in receipt of one of the defined benefits listed below.

Please see the table below to see what funding is available and if you have any queries please contact the A1 team on 0845 6000 337

  Funding figures valid from 1st January 2011

 *Defined benefits

• Council Tax Benefit
• Housing Benefit
• Income-related Employment and Support Allowance
• Income-based Jobseekers Allowance
• Income Support
• Attendance Allowance
• Disability Living Allowance
• War Disablement Pension which includes either a Mobility Supplement or Constant Attendance Allowance
• Disablement Pension which includes Constant Attendance Allowance
• State Pension Credit
• Child Tax Credit where the relevant annual income is £16,190 or less
• Working Tax Credit where the relevant annual income is £16,190 or less

Important information and find a registered installer

Make sure you discuss A1 Low Carbon Solutions grant funding with your installer. There are various levels of grant funding available to you for fuel switching which registered installers can apply for on your behalf and will be reflected in their quotes to you.

How to find a registered installer, please contact Vokèra’s upgrade team on: 01727 744038 or visit: http://www.a1-lcs.co.uk/search/

We recommend you get more than one quotation for your heating system upgrade and always use a Gas Safe Registered Installer, check the card by visiting: www.gassaferegister.co.uk.

Vokèra’s smallest condensing combi boiler the Compact A, has been specifically designed to meet the new Part L of the Building Regulations.

Following the success of Vokèra’s Compact HE range, the new Compact A is a cost effective combi, offering low NOx and is available in two outputs of 25kW and 29kW.

The name Compact describes the boiler perfectly as it is 40 per cent smaller and 22 per cent lighter than the previous model, while the standard Vokèra layout enables quick and easy equipment replacement or upgrade if required.

Alister Maclachlan, technical director, for Vokèra, said:  “We’re really excited about the Compact A, as we believe it offers installers a quality, modern boiler which meets all latest legislation requirements, but at a cost effective price for domestic customers.

“The exclusion of Band B boilers from Part L of the Building Regulations, which came into force in October 2010, means the Compact A is the perfect choice as a cost conscious solution that satisfies the legislative change and meet the needs of installers and customers alike.”

Compact A offers a number of key benefits including pre-mix combustion and a combined parallel and in-series hydraulic circuit.  The expansion vessel is side-mounted and a cyclonic separator is fitted as standard.  The interface is simple to use and a clock kit and wireless programme kit are available as additional options.

To find out more click here

Vokèra the UK’s first boiler specifically designed for outside installation on a balcony or mounted on an external wall. Based on it’s leading combi boiler Unica HE, the Unica Balcony HE offers the same excellent quality, reliability and efficiency, but with increased siting flexibility and the benefit of space saving in a home.

The Unica Balcony HE’s IPX5D rating means that Vokèra is the only UK manufacturer to offer an external boiler able to withstand the elements without the need for additional protection. Not only is it ideal for flats and apartments with limited inside space, but the Unica Balcony HE can also help solve a range of flueing and condensate problems.

When a boiler is not located near an external wall, flue clearances can be difficult to achieve, so the Unica Balcony boiler is a perfect solution. In addition, with many properties wishing to update to a condensing boiler, the issue of condensate disposal can cause problems. Installing a boiler to the outside of the property also means that there is no need to inaugurate lengthy soak away pipework, making the installation quick and easy.

Like the Unica HE, the Unica Balcony HE is a condensing boiler, with the potential to reduce running costs by up to 35 per cent when compared to a conventional boiler. The patented aluminium heat exchanger provides excellent thermal transfer and is corrosion resistant, helping to keep the boiler in good condition and reducing the need for costly maintenance work. The built-in frost protection also helps to keep repair work to a minimum, protecting the appliance from damage during cold weather.

The Unica Balcony HE boiler is initially available in 32kW output, with further models to be added to the range later this year. This latest product from Vokèra demonstrates the company’s ongoing commitment to investing in its comprehensive heating solutions that help the installer overcome complex installations.

In addition to the Unica HE range, Vokèra has a comprehensive offering of heating solutions to suit domestic applications, incorporating stylish designs and many optional extras as standard, at an affordable price. For further information call Vokèra on 0844 391 0999 or visit www.Vokèra.co.uk.

Leading boiler manufacturer Vokèra is encouraging Benchmark registered installers to join their recommended installer list, offering them the opportunity to gain customer leads.

Vokèra recognise that particularly because of current difficult market conditions, maximising every opportunity to find new customers is important to installers. Linking up with a leading manufacturer like Vokèra can be the key to finding leads. To join the scheme, Vokèra prefer installers to be Benchmark registered, and their necessary qualifications must be up-to-date as well being a loyal Vokèra affinity member*.

Eleanor Waldron, marketing director at Vokèra, said: “The recommended installers list is a great way to ensure that we are promoting the best standards in the industry. For those installers who sign up, there is the bonus of being given leads which could turn into work for them, offering them the help they might need during these tough times.”

Vokèra actively supports the HHIC Benchmark scheme, which ensures that the installation and servicing of domestic heating and hot water products are carried out to the highest standards by a fully qualified installer. To find out more about Benchmark or to become a member, visit the Heating and Hot water Industry Council (HHIC) website: www.hhic.org.uk .

For further information on Vokèra’s installer scheme, or how to become a member, email marketing@vokera.co.uk.

* Other conditions apply.

As part of its commitment to workable, renewable energy solutions, heating manufacturer Vokèra has launched Aria, the company’s first air source heat pump.

Available in three outputs – 6.8kW, 8.3kW and 11kW – Aria is suitable for new build and retrofit applications. The Aria air-to-water heat pump converts ambient heat from the atmosphere into useable energy for heating and hot water, helping homeowners to save money on their fuel bills and reduce their carbon footprint. The heat pump can be effective even when the outside temperature falls below zero, and can still produce heat from conditions as low as minus 15oC.

The Vokèra air source heat pump works by extracting the heat from the outside air, raising it via a compressor, and then transferring it to a plate heat exchanger. The exchanger then provides heat for central heating or underfloor heating, and also hot water if a cylinder is added to the system. Although flexible enough to be used for a range of applications, Aria is best suited to properties with an underfloor heating system, as they require lower flow temperatures.

Able to operate on a single-phase electrical supply, Aria has a Coefficient of Performance (CoP) of up to 1:3.9 – so for every 1kW of electrical energy used, a heat output of 3.9kW is produced, making it very efficient in operation. For additional energy savings, Aria can be used in conjunction with a solar thermal water heating system, such as Vokèra’s Zenith package.

Aria has been designed to be sited outside of a property and, without the need for any extensive installation preparations, the pump is flexible enough to be used in both new build and retrofit applications. For installers, the heat pump is straightforward to install as it incorporates many system components as standard.

As with most renewable technologies, homeowners with an air source heat pump may require a traditional boiler to provide supplementary heat to make up any temperature differentials. This ensures stable and continued end user comfort. Aria is compatible with all Vokèra boilers.

For the end user, the heat pump is very simple to use. In addition to being easy to operate, Aria is also low noise at just 58db when in use.

Robert Lockhart, Vokèra’s renewables project manager, said: “We are really excited about the launch of our Aria air source heat pump. As a flexible renewable solution, it can be used for both hot water and space heating – something many other ‘green’ options are unable to offer. And when combined with solar thermal water heating, an air source heat pump is a very environmentally friendly and practical option for homeowners.”

The introduction of Aria is the natural next step for Vokèra’s growing renewables portfolio. The company launched the Zenith solar thermal package in 2007 and since then has undergone an intensive renewable launch programme, including the addition of evacuated tubes and inset solar panels to the Zenith range, the Neutro wood pellet boiler and now the air source heat pump.

Vokèra offers a comprehensive range of heating solutions to suit most domestic applications, offering stylish designs and many optional extras as standard, at an affordable price. For further information call Vokèra on 0844 391 0999 or visit www.Vokèra.co.uk.