Green accounting from York-based HippoInnovative and highly energy efficient heat recovery units have been specified at an eco office retrofit project in Liverpool, cementing the importance that ventilation plays in meeting increasingly stringent carbon reduction targets in commercial developments.

The transformation of a solid wall property in the Sefton Park area of Liverpool into a state-of-the-art eco office suite with residential accommodation upstairs has reached completion, as the new energy efficient development welcomed its first commercial tenants.

This former doctor’s surgery with the lowest energy performance rating, has been transformed into a near Passivhaus standard eco office development, providing six individual offices ranging from 11.1 to 17.1 m2 in size and a large shared space for reception, meetings, kitchen and toilet/shower facilities.

The 1950 detached property lies within a conservation area of mainly Edwardian and Victorian housing and although non-typical of the area, the refurbishment still had to conserve its original features whilst incorporating the latest energy efficiency and sustainability credentials, marrying period charm with contemporary technologies.

The new Ullet Road Eco Offices building showcases a range of low carbon technologies, majoring on the use of electricity instead of gas, with low energy and low noise ventilation specified as part of the build.

Muro by Xpelair Ventilation Solutions – a professional through the wall heat recovery unit – was chosen by the developers for its quiet operation and excellent energy saving properties, in keeping with the requirements of the build, whereby all products used had to meet a high efficiency benchmark.

“I first became aware of Muro at a Greenbuild EXPO over two years ago, so it had been on my radar since then,” explains John Garrett, owner of the Ullet Road Eco Offices development. “Initially, I wanted to go down the MVHR route but the consultants we used suggested it wouldn’t be the best solution for the property. I was still keen to install a product that offered the benefits of MVHR, though, and I also wanted the option of being able to retrofit at a later date, so Muro was an ideal solution.”

Muros were installed in both office and apartment kitchens, and together with hydroscopic natural clay plasters on key walls, provide humidity control as well as fresh air for the kitchens and surrounding areas.

“With the benefit of hindsight, I would also have installed units in the two apartment bedrooms.  Fortunately, we introduced natural passive stack ventilation through new openings in the existing chimneys, but controlled ventilation with heat recovery would have been preferable,” he added.

Ullet Road was the first project to install Muro in the UK; the product already well established in the German market. As such, it was something of an unknown quantity for the development team, but the since the property has opened, the installation has worked well.

When you’re working to near Passivhaus standards, the right ventilation is essential, especially when there’s very little natural ventilation coming into the building. Muro ensures the right conditions are maintained and is an ideal solution for the retrofit market where achieving Passivhaus can be challenging; offering a practical and highly efficient option, especially as an alternative to whole house MVHR systems.

Most electricity for the running of the eco offices and apartment is generated renewably on site from the two solar PV arrays, the one on the front elevation using solar tiles integrated into the roof. Additional electricity from a 100% renewable supplier, Good Energy, is purchased off-peak during the night, and used to charge cars and power the air source heat pump used to top up the hot water and heat or cool the building through the under-floor pipe-work.

External wall, roof and sub-floor insulation, encapsulation of existing lead lights into bespoke triple glazed windows, reinforced grass car park with EV charging points, a ‘living’ green roof and two solar thermal collectors for water heating, are among other eco measures taken by the developers to ensure the retrofit delivers on its green aspirations.

The addition of Muro compliments the offering, giving end users all the benefits of heat recovery, such as negligible heating bills, running costs and improved Indoor Air Quality (IAQ), without the expense or added site time of installing ducting required for MVHR. The time saving and low energy qualities made Muro the perfect solution for this retrofit project.

Xpelair’sMuro solution is perfectly suited to domestic, light commercial and healthcare installations, designed for single room and dMEV system applications, allowing for individual units to be installed in separate rooms throughout a building.

“Muro is one of the most efficient units on the market, delivering 80% heat recovery while operating at very low noise levels,” explains Vic Brown, Head of UK Ventilation at Xpelair. “Keeping noise to a minimum is crucial in today’s home and office environments; the latest stats show that high levels of noise can become a real issue for occupants. Because Muro is one of the quietest heat recovery units on the market, it’s ideally suited to applications like this where heat and energy loss need to be kept to an absolute minimum.

“The unit’s long life DC motors, four-speed control and intake or extract options, alongside automatic frost function, low energy backdraught shutters, built-in air sensors and optional humidistat controls are just some of the many benefits of Muro. All of these market-leading features are ultimately designed to improve the efficiency of each unit, whilst providing users with greater control over their ventilation,” he adds.

Such is the instant success of the new office development, Ullet Road was shortlisted for its first industry award  – the Liverpool & Sefton Chambers of Commerce Innovation and Technology Award – which highlights the successful delivery of the developer’s energy efficiency goals and the growing appetite for new and retrofit office space in the market.

In addition, the Ullet Road Eco Offices has exceeded the ‘best practice’ certification by the Airtightness Testing and Measurement Association (ATTMA) for its 2.25m3/m2h airtightness measurement.

Xpelair’s inclusion in eco retrofits like Ullet Road is testament to the energy efficient properties of its range; the launch of Muro adding to the growing list of energy efficiency products available. The environmental credentials of the company are well founded, with Xpelair being the only UK manufacturer with a product to be granted Passivhaus certification for its the Xcell 300 and 400, which is already in high demand in eco developments, alongside Muro.

The development team will seek BREEAM In-Use certification later this year.