There is an increasing awareness that a major difference between a passive house and a standard BASIX or NatHERS house is airtightness. When the windows and doors are closed, a passive house is extremely airtight, and therefore a means of ventilating the house is required.
A heat recovery ventilation system is an energy-efficient fan unit with a heat-exchange core and ducts that bring fresh and filtered air from the outside of the house into the living areas. While at the same time removing stale and moist air from the kitchen and wet areas. The heat-exchange core allows the warmth or the cool of the house to be captured and passed into the incoming fresh and filtered air. The system is also used when the windows and doors are open.
There are a number of different brands of HRVS being imported into Australia.
When I did my research, there were good options from Stiebel-Eltron of Germany, Dantherm from Denmark and Brinks of the Netherlands. There are others. We opted for the Zehnder 375 Standard. Zehnder is multinational Swiss company.
Because we were very new to passive house and heat recovery ventilation, it was important to find a distributor with a high-quality product and who was willing to recommend and liaise with a good installer. This was as much about correct and competent installation as it was about after-sales service and support.
The Zehnder distributor that we dealt with was Fantech. It’s a company that was started in Australia and is now part of the Elta Group from the U.K. They have a nationwide network of offices, but the HRV business is run from their office in Dandenong South, Victoria.
Fantech were able to provide a HRV layout plan and specifications as part of their service. This was a better option than finding an engineer to do the work separately. The process was quite straightforward. I sent my floor plans, which they used to overlay their diagrams and add the specification details. They made a unit recommendation.
A passive house consultant could also help you with this.
Once I had chosen an installer from the contacts that they provided, I received a quote directly from them for supply and installation. Fantech supplied the installer with the unit, ducting and other necessary consumables.
There may have been changes since I was looking into it, however the longest warranty being provided by any manufacturer for a domestic installation was 2 years. Comparable units from each manufacturer seemed to be roughly equivalent in efficiency and noise levels.
Supply and installation of the system cost roughly $17,500.00, inclusive of GST (based on prices in March 2021). Something to be aware of is the ongoing cost of filter changes.
I will update this blog with information about living with the HRVS as we go along.
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