Step-by-step: installing the HRXE MVHR system from Domus Ventilation

Step-by-step: installing the HRXE MVHR system from Domus Ventilation

Domus Ventilation offers a handy step-by-step installation guide to its HRXE Mechanical Ventilation with Heat Recovery (MVHR) system.

Mechanical Ventilation with Heat Recovery (MVHR) systems have never been so popular. They improve indoor air quality, making for a more comfortable and healthier home environment, and can provide up to 50 per cent savings on energy bills due to the reduced heating demand. But just how easy is an MVHR system to install?

The Domus Ventilation HRXE range, which is suited small to medium size residential properties, has been designed with installers in mind. Measuring just 507mm (h) x 356mm (d), it’s a highly compact unit that can be easily installed in cupboards both onsite and in pre-fab modular construction.

Here’s our step-by-step guide to installing an MVHR system, featuring our HRXE unit and Domus ducting:


  1. Identify the location of the MVHR unit

A clear working space is required around the installed unit to allow the cover to be removed and provide sufficient access for maintenance such as filter change. Allow a minimum of 350mm in front of the unit. The fan must be installed indoors, on a suitable wall away from direct sources of frost, heat and water spray or moisture generation.

A clear working space is required around the MVHR unit


  1. Identify extract / supply areas

The MVHR unit is designed to extract air from all wet rooms e.g. bathroom, kitchen, utility room (with sink). Supply air should be to all habitable rooms e.g. bedrooms and lounge.


  1. Install ducting

Round or flat channel rigid duct should be used and held in place with a support strap every 750mm. Alternatively, semi-rigid Radial ducting systems are a great way of reducing install time on site. Ducting must be installed in such a way that resistance to airflow is minimised, with bends kept to a minimum. A minimum distance of 300mm between the MVHR appliance and any bends in ductwork is recommended.

  1. Seal ducting

Seal ducting joints with silicone type sealant such as DDSEAL.

  1. Fit insulation to ducting

Install ducting insulation on the outside of the external air inlet duct and the air outlet duct from the unit, to prevent condensation. The Domus Thermal system is easy to fit and actually exceeds the Government’s Domestic Ventilation Compliance Guide standard for ducting insulation.

  1. Install grilles

Extract / input grilles should be valves which are adjustable for commissioning. External grilles are to have a minimum free area of 12,250 mm2.


  1. Fix the mounting bracket for MVHR Unit

Fix the mounting bracket to a solid wall, ensuring the interlock side is at the top. If it’s not practical to use a solid wall, the MVHR unit should be fixed to a stud partition with a 25mm minimum thickness MDF panel solidly fixed behind the plasterboard.

  1. Wall mount the MVHR unit and connect to power supply

Install the unit on the wall by ensuring the bracket fixed to the rear of the unit interlocks over the wall mounted bracket. The cable from the mains power supply should be connected to a fixed wiring installation, via a fused isolator, in accordance with current IEE wiring regulations. For good EMC engineering practice, any sensor cables or switched live cables should not be placed within 50mm of other cables or on the same metal cable tray as other cables. The unit must be earthed.


  1. Connect condensate drain

If the condensation pipe is fitted in an unheated space the pipe should be insulated.

  1. Check filters prior to commissioning

Prior to commissioning, take the protective film off the filters and replace. Ensure they are dust and debris free.

  1. Commissioning

A calibrated moving vane anemometer and hood are required to carry out commissioning. Adjustment valves should be locked in place to prevent further adjustment.

  1. Post Commissioning

The clear panel covering the control has an adhesive panel which should be exposed and sealed post commissioning to prevent tampering.

As simple as that! One happy installer, one happy developer and one soon to be happy home owner.


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