Mechanical Ventilation Decisions

The mechanical ventilation system is now up and running in the house. A Passivent iHybrid system was chosen in the end after much consultation between the design team members, manufacturers and the resident.

The key concern was to avoid overheating. Although energy modelling demonstrated a low risk of overheating on a theoretical level, it was still a concern due to the pipe runs and heat sources within such a well insulated dwelling. For that reason, questions were raised about systems which had no summer bypass for the heat recovery system

and the iHybrid system seemed an excellent solution.

Dennis Bates of Passivent said of the system:

A ventilation system only performs as it should provided that it is installed correctly. Air tightness within the system and unobstructed clear air routes are key to ensuring that moist, stale air is removed from the property, and fresh clean air is fed in, so not causing any potential excess moisture, leading to damp and mould growth.

Noting that installation is a key factor, Passivent have a team of approved Mastercare installers, whom are trained by the manufacturer to ensure that every project not only has the right system installed, but it installed to the highest quality, providing the promised levels of ventilation. The unique iHybrid system which was used on the project combines Heat Recovery with natural Passive Stack Ventilation, providing energy savings and i

ncreased longevity over standard heat recovery systems, was installed by one such Mastercare Installer, Brooklyn PSV. The quality and professionalism of the approved installer network means that the system was commissioned and will continue to operate as designed throughout it's life, providing occupants with fresh clean air.'

The ventilation fans will now be monitored for 2 years to ascertain the reduction in electricity consumption due to the passive stack principle being adopted during summer months.

December Update - External wall insulation

Work has been progressing rapidly on site and is close to completion both internally and externally. Brick slips were chosen to closely match the existing bricks in order to maintain the character of the property, with render being applied to the rear of the property. These were applied to the prepared mesh on the phenolic insulation, spaced and then pointed as outlined in the photos. This resulted in a very realistic finish similar to the original appearance of the property.

Importantly, this was also the time that excavation for the perimeter wall insulation could be carried out, to be filled with EPS later, dramatically reducing perimeter losses through the ground floor.