The company, the UK’s leading supplier of domestic ventilation solutions and the only manufacturer to offer a full ambit of natural and mechanical strategies, maintains its ‘automatic’ iPSV (intelligent Passive Stack Ventilation) and iMEV (intelligent Mechanical Extra ct Ventilation) simplify compliance with the new Approved Document F and L whilst reducing reliance on occupier input and understanding of the ventilation system, thus ensuring continued long-term energy efficiency and reduced maintenance bills.
Its claim is reinforced by research undertaken by University College London, into two developments, one of homes with Passivent’s iPSV installed and which achieved an EcoHomes ‘excellent’ rating, and one with a MVHR (mechanical ventilation with heat recovery) system. Across the Passivent homes, energy consumption was less overall than the MVHR dwellings, and varied only 2.8fold; in the MVHR homes, energy consumption varied between the homes 6fold!
“The aim was to have ‘normal’ houses, with very low energy [but] occupants find the MVHR noisy, draughty, cold at night so turn it off. The up/down thermostats on the MVHR give limited feedback, so the system tends to be used as ‘on’ or ‘off’. In the Passivent ventilated homes, they had no need to turn the ventilation ‘on’ or ‘off’, and just adjusted the central heating to individual preference,” elaborated head of the research programme Dr Ben Croxford.
Dennis Bates, Passivent Domestic Product Manager, adds “The over-riding considerations for the home’s occupants are usually cost and noise. If they think running a fan costs them money, and/or disturbs them, they will turn it off, without considering the consequences to their- and the building’s- health! But we need air to function; creating airtight homes is basically sealing a box and expecting people to live inside, in an increasingly damp environment, without adequate supply of fresh air.
“With most mechanical extraction and MVHR systems, there is also a maintenance issue: filters need regular cleaning and replacement, for example. How many occupants will remember and physically undertake such jobs? They want ventilation systems which are quiet, cost nothing to run, and require no occupier input to operate or maintain.”
Both Passivent iPSV and iMEV are automatic, ‘fit and forget’ systems, harnessing natural air movement (convection and the venturi effect) to draw used air out of the home, and fresh air in via humidity sensitive extracts which open and close according to moisture levels in the internal air. Passivent iPSV has no fans or moving parts which need replacing, and is proven to work in airtight (0m3/m2@50Pa) homes. The company’s iMEV system uses a single, remote, low energy fan to boost extraction where long runs of ducting are needed, but still ensures appropriate levels of ventilation regardless of dwelling use or occupation.
Both systems further help achieve a minimum Level 3 under the Code for Sustainable Homes, help compliance with Lifetime Homes guidelines, and achieve good practice under the BRE and The Housing Corporation’s ‘Sustainable Homes: Embodied Energy in Residential Property Development’. In comparative lifetime costs, they are also more cost-effective than alternative mechanical extraction solutions.
Passivent supplies background ventilation solutions including tricklevents and through-wall ventilators, standard and ‘intelligent’ mechanical ventilation, passive stack natural ventilation and the new and innovative iHybrid, which combines natural ventilation with heat recovery to yield a 55% reduction in fan energy use and a 39% saving in lifetime costs over standard mechanical heat recovery, with its systems supported by its nationwide Mastercare scheme of approved installers. Its ability to design, supply and install all domestic ventilation solutions means it can provide authoritative, unbiased advice to the building industry to ensure new schemes comply with the new Approved Document, and all other regulatory requirements.