Case Study Types: Residential

Domus Ventilation’s HRX-aQ Mechanical Ventilation with Heat Recovery (MVHR) systems and Domus ducting are being installed into the striking No. 1 Thames Valley apartment complex in Bracknell, Berkshire.  This extensive development sees the building converted from offices to 130 single bedroom apartments laid out in two wings with floor-to-ceiling windows. 

As with most office to residential conversions, No. 1 Thames Valley has presented a number of challenges along the way, not the least the ventilation.  Thankfully, Working Environments, which is responsible for the design, supply, installation and commissioning of the mechanical, public health and electrical services, has plenty of experience in this field.  This has enabled them to meet these challenges, from ducting that needs to run through the building façade to trying to match the ventilation grilles with the terracotta tiles in place.

Working Environments specified the Domus Ventilation HRX-aQ for this demanding project as the MVHR system was readily able to provide the level of indoor air quality required.  Other factors that were taken into consideration were the pricing and cost-efficiency, plus the level of support provided by Domus Ventilation.

The HRX-aQ MVHR system is ideally suited to No. 1 Thames Valley as it intelligently manages air conditions for maximum homeowner comfort.  This is achieved through advanced AMIE (Air Management for Indoor Environments) technology including features such as digital humidity control, automated summer bypass and accurate system balancing.

Unlike conventional humidity sensors, the HRX-aQ enables occupants to have direct control over managing the humidity levels in their home to suit personal comfort levels.  By accurately measuring air humidity, the HRX-aQ’s extract speed automatically changes from background to boost as the level of humidity increases, thereby providing optimal ventilation performance.

The HRX-aQ features advanced bypass control, programmable by occupants based on time and temperature.  In standard mode the MVHR units work by warming fresh air drawn into the building using the heat from waste stale air extracted from the kitchen and wet rooms.  In conjunction with multiple time controlled bypass options (night time free cooling), the HRX-aQ also detects when air temperature reaches a pre-set level and intelligently activates the bypass mechanism allowing in cooler, fresh and filtered air.

Working Environments has installed the HRX-aQ units at No. 1 Thames Valley within each apartment’s bathroom in the ceiling void, with the MVHR controller located in the utility cupboard.  This is the first time the company has used HRX-aQ and, according to Robert Druce, Project Manager at Working Environments, they have found the units very easy to install, further assisted by the online training provided by Domus Ventilation.

Measuring just 199mm in depth and weighing from just 7.9kg, the HRX-aQ is compact and light enough to be easily installed in the most restrictive of ceiling voids.  It can be simply designed-in with a straight in-and-out duct run and, in the case of No. 1 Thames Valley, is directly fitted to Domus 204x60mm Supertube rigid ducting for an air-tight connection, minimising pressure drops virtually eliminating air leakage.  Its offset duct connections also mean that any duct crossover is much more straightforward.  The accumulation of HRX-aQ’s quick and simple installation features make for one of the lowest install costs of any MVHR in the market today.

 Its offset duct connections also mean that any duct crossover is much more straightforward.  The accumulation of HRX-aQ’s quick and simple installation features make for one of the lowest install costs of any MVHR in the market today.

Domus Ventilation’s HRXE Mechanical Ventilation with Heat Recovery (MVHR) and CMX-MULTI Mechanical Extract Ventilation (MEV) systems, along with Domus ducting, are being installed in to the new Kilburn High Road residential development in North West London:

Kilburn High Road is a development of one and two bedroom apartments from Kilburn Developments Ltd.  Located on one of London’s busy main roads, indoor air quality has been a key consideration, which drove JP Electrical Ltd. to specify and install Domus Ventilation’s range of mechanical ventilation systems.  Commenting on his choice, Director Nick Jordan stated: “They are really good units and easier to install than others I’ve used.  I’ve never had a problem with them.”  Jim also has praise for the service provided by Domus Ventilation: “Domus did all the design drawings for this project free of charge which massively helped and they have provided on-site support too.”

Domus Ventilation HRXE MVHR systems with NOX-FILT in-line carbon filter have been installed in the ground level apartments within a cupboard, with CMX-MULTI MEVs in the remaining apartments, fitted in the ceiling voids.

The HRXE MVHR combine supply and extract ventilation in one system.  They efficiently recover up to 90% of the heat typically lost in waste, stale air and use it to temper the fresh air drawn into the apartment via an advanced heat exchanger.  The filtered, pre-warmed air is distributed to areas of the home such as living rooms and bedrooms, effectively meeting part of the heating load in energy efficient dwellings.  The systems themselves use very little energy due to their efficient design, including a very low Specific Fan Power (SFP) down to just 0.57W/l/s. 

To filter out harmful airborne contaminants prevalent in our cities, the HRXE has been fitted with Domus Ventilations NOX-FILT in-line carbon filter.  Designed to work on the supply leg of the ducting system to the HRXE, NOX-FILT removes up to 99.5% of nitrogen dioxide (NO²) pollution from entering a home. 

Domus Ventilation’s CMX-MULTI is an extremely compact and highly energy-efficient centralised MEV.  It extracts indoor pollution and draws moisture-laden air out of wet zones, such as kitchens and bathrooms, depositing it outside for greatly improved indoor air quality and environmental comfort.  At just 125mm in depth, the CMX-MULTI is the smallest and lightest MEV on the market, enabling it to readily fit into ceiling voids, as is the case at Kilburn High Road.  As with the HRXE, the CMX-MULTI is energy-efficient, with an extremely low Specific Fan Power down to 0.1457W/l/s – the lowest in the market today and well below Building Regulation Part L requirements of 0.5 W/l/s. 

To ensure maximum systems performance, Domus Supertube 204x60mm rigid ducting and EasiPipe 125mm round rigid ducting have been used with the mechanical ventilation systems. These duct systems offer improved system performance through the exacting tolerances and engineered fit of the system, whereby pressure drops are minimised and air leakage virtually eliminated.

In line with Building Regulations, Domus Fire Collars have been used wherever a hole has been made in a compartment wall for the ducting to pass through in order to restore the walls’ fire rating.  Domus Thermal ducting insulation has also been used where the ducting passes through unheated areas and voids, to prevent condensation forming.

Domus Ventilation’s HRXE-HERA® Mechanical Ventilation with Heat Recovery (MVHR) systems have been specified for the be:here Hayes build-to-rent residential development in West London.  The MVHR units are being installed as a retrofit, replacing the previous units that had come to the end of their working lives.

be:here Hayes consists of 119 one, two and three-bedroom apartments, all of which have been designed specifically for the private rental market.  When the building was designed, Domus Ventilation’s Silavent MVHR ceiling mounted units were installed.  These are now being gradually replaced with Domus Ventilation’s latest MVHR model, HRXE-HERA®.  These new energy efficient units are smaller than their predecessors making them ideal for wall-mounting in the apartments’ storage cupboards.  This solution also provides users with easy access to change the filters.

As a retrofit solution, HRXE-HERA® has proven ideal for be:here Hayes as they readily use the existing Domus ducting.  Spigots on the top of the unit are 125mm for direct connection to the ducting, with adaptors available to enable direct connection to other ducting sizes for a quicker and more cost-effective installation. 

With energy efficiency being a key part of the building’s design, including air permeability and heat loss parameters that go beyond that required by Building Regulations, Domus Ventilation’s HRXE-HERA® MVHR have proved an ideal solution for be:here Hayes.  It filters and pre-warms fresh air drawn into the apartment using the heat from waste stale air extracted from the kitchen and bathroom using a heat exchanger.  This prevents the build up of condensation and mould, whilst improving indoor air quality by providing continuous balanced ventilation.  It’s advanced heat exchange proficiency enables up to 95% of waste heat to be recovered, for energy efficiency.  It comes with 100% thermal (summer) bypass which automatically activates when the air temperature reaches a pre-set level, allowing in cooler, fresh, filtered air without warming it through the heat exchanger.  The smart design of the HRXE means there is no reduction in airflow when operating in bypass mode.  Manual boost buttons have also been installed within the apartments to increase air flow when required.

Akash Sharma, Property Manager for be:here Hayes, worked closely with Domus Ventilation to ensure the best solution for this retrofit project and understands the importance of ventilation: “these are well sealed apartments and feature bathrooms without external walls, so there are no windows to ventilate them.  Without mechanical ventilation, condensation and mould would be a major problem, so MVHR systems were a key feature from the very start.  The previous Silavent units had performed well and my relationship with Domus Ventilation has always been good, so moving on to the HRXE units was a natural progression.  Dean Miranda [Domus Ventilation Specification Sales Manager] and one of the people from Domus’ technical team visited the site so they could fully understand what was required and made their recommendations from that.  The HRXE-HERA® has proven ideal as my in-house team have found it easy to install – we did a test run in one of the apartments first – and it’s proven to be cost-effective and efficient.” Domus Ventilation has a well-deserved reputation for quality, supported by excellent technical support, from a market leading manufacturer and designer.  It is well placed to offer immediate, practical solutions to Building Regulations Parts F & L.