Medium density housing throws up some unique challenges for designers and specifiers. Not least is the challenge of running services through multi-storey buildings. Multiple dwellings in a single, multi-storey structure offer limited to no access to the roof space for each dwelling, which is where ducting for a home ventilation system would usually be installed. Hometech has developed a new through-wall ventilation system to overcome this challenge.
Unovent H-line is a modular, through-wall, heat recovery ventilation system designed here in New Zealand. The reversible fan removes stale air, then replaces it with filtered air from outside. It can be installed through almost any exterior wall between 110mm and 210mm thick, allowing for flexible installation anywhere that requires ventilation.
H-line's internal ceramic core makes it an excellent solution with low energy loss, particularly in temperature controlled environments. As H-line removes and replaces stale air its core operates as a heat exchanger. It absorbs the preheated or cooled indoor air temperature when extracting air from inside. When it reverses, the incoming air reclaims the temperature from the ceramic core.
H-line has additional settings that offer excellent flexibility, allowing the fan to run in one direction only if desired. It can be set to intake only, drawing fresh air from outside at the outside temperature, making it great for summer days with no air conditioning. Alternatively, it can be set to continuous extract when the occupancy status calls for it.
When correctly specified, H-line meets NZBC G4 fresh air compliance, where outdoor air supply at a rate of 0.35ACH (air changes per hour) is required if 5% openable window area is unachievable. H-line also meets Homestar v5 for residences targeting 6 or 7 stars, which must now have continuous extract ventilation with higher efficiency EC fans as a mandatory minimum.
The H-line system comes complete with an EC motor as well as a ceramic heat exchanger core, so it can qualify as continuous extract or balanced ventilation, depending on the fan settings chosen. On medium air flow H-line achieves the required air changes for a 27m² space at 2.4m stud height. One to two H-lines can provide the balanced ventilation required for most living rooms while only one is typically needed for bedrooms.
Hometech offers design services compliant with NZBC G4, Homestar and Healthy Homes as required and can supply PS1 statements for its designs (PS1 = design producer statement), which are often required by councils for apartment ventilation designs.