How To Plan For MVHR In Your New Build?

Building a new home is an exciting process, and with today’s focus on energy efficiency, you’re likely aiming for an airtight house.  While airtightness is great for keeping heating and cooling costs down, it can also lead to poor indoor air quality. Installing trickle vents and extractor fans at the last minute compromises the airtightness you aimed for and as a result the heating bills are higher than expected.

Mechanical Ventilation with Heat Recovery (MVHR) systems provide a solution by bringing in fresh air from outside while retaining heat from the outgoing stale air.  This translates to a healthy and comfortable home without sacrificing energy efficiency.

If you’re embarking on a new build project and considering fitting an MVHR system for the first time, here are some tips to planning for a seamless installation.

1.     Finding a Location for Your Unit

The MVHR unit itself needs a designated space that’s easily accessible for future maintenance. This could be a utility room, loft space, or even a cupboard. Ideally, locate the unit away from main living areas to minimize noise during operation. Remember, it will also need a nearby power source.

Going Deeper: Unit Location Considerations

  • Noise: MVHR units can generate some noise, especially during boost mode. Placing the unit in a utility room, loft space, or dedicated plant room keeps noise out of living areas.
  • Accessibility: Remember, you’ll need to access the unit for maintenance. Avoid tight crawl spaces or locations behind fixed fixtures.
  • Power: The unit will need power. Plan the location to minimize the cost of running new electrical conduit.

2.     Planning the Ductwork

The ductwork will most likely run through your loft, joist space, or floor. Consider the depth of your ceiling void or the size of your web joists before finalizing them. Smaller voids might require using more expensive flat ducts. Our standard size ducts need at least 254mm deep web joists. If you aren’t using engineered joists, you’ll need a ceiling void. We offer various duct sizes and system designs to accommodate most ceiling void heights (from 70mm and up).

For multi-story builds, the ducts will need to travel between floors. Consider using a 60mm rectangular ducts, which can be hidden within stud walls. If you don’t have stud walls, you might need a dedicated service riser or designated locations to conceal the ducts.

Ductwork Planning Considerations

  • Ceiling Void vs. Floor Void: Running ducts through the ceiling void is generally easier, but it does reduce ceiling height. Floor voids can also work, but require careful planning to avoid compromising floor insulation.
  • Bends and Turns: Minimize the number of bends and turns in the ductwork, as these can restrict airflow and reduce efficiency.
  • Duct Size: While smaller ducts are more discreet, they can also restrict airflow. Consult with an MVHR specialist to determine the optimal duct size for your system.

3.     Aesthetics and Ventilation Points

Besides the vents in each room, the MVHR system should be largely invisible. Vent colours and placement can be decided later. However, if you have aesthetic requirements (especially in listed buildings), you might have limitations on external wall penetrations.

The MVHR system needs fresh air intake and stale air exhaust, which can be located on the roof, wall, or soffit. Plan accordingly if you want to hide these external vents. For instance, if you don’t want them on the front of the house, avoid placing the unit there. Consider alternative locations like a gable wall or outside the loft if you want to avoid roof terminals. Creating a deeper soffit can also conceal the vents.

Planning Vent Locations

  • Airflow Path: Plan the vent locations to create a balanced airflow path throughout the house. Fresh air inlets should be located in living areas, while stale air outlets should be located in kitchens, bathrooms, and utility rooms.
  • Discreet Placement: Vents can be placed high on walls or even in ceilings to minimize their visual impact.
  • Listed Buildings: Consult with your architect or planning department if your house is listed, as there may be restrictions on external vents.

Getting Started with MVHR

This is a general guide, and each project will have unique considerations.  If you’d like a more specific plan for your new build, consider using our design service for a detailed design and quote.

By planning for MVHR early in the building process, you can ensure a healthy, energy-efficient, and comfortable home for years to come. If you’re ready to breathe new life into your new build project, we can help.  Our team of MVHR specialists can guide you through every step of the process, from initial design to installation and aftercare.

Contact us today for a free, no-obligation consultation.  We’ll discuss your specific requirements and answer any questions you may have.  Together, we can create a bespoke MVHR system that perfectly complements your new home.

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