FreshR Ductless/Filterless HRV

Game-changing ventilation technology for low energy houses, saves £500/annum in ventilation heat losses in a 200m2 house, pays for itself in 7 years, encased in Polypropylene with a sleek flush sheet metal finish. For current prices check the Vaventis website

  • World's most efficient HRV (heat recovery ventilation) delivers a 7 year payback compared with 50 years for "always on" ducted systems.
  • Creates dwelling Zones with external quality air, nearby rooms are ventilated to these zones, toilet smells are extracted externally.
  • Eliminates £50/annum Filters costs, Eliminated Ducts reduce fan pressure drop losses by 70%.
  • Fans independently adjust to maintain heat exchanger efficiency, improving performance by 10% over HRV with equal fan speeds.
  • Gases equalise rapidly in still air ensuring Humidity and CO2 arrive at the FreshR unit quicker by air than through ducts.
  • In a 200m2 house, ducted HRV has annual running costs of £120/annum, for 2 FreshR units its £5/annum.
  • In a 200m2 house, ducted HRV has ventilation heat-losses of £250/annum, with 2 FreshR units its £50/annum, only occupied spaces are ventilated.
  • CO2 and Humidity monitors constantly check air quality and adjust fan speed accordingly.
  • Fits discreetly into the external wall, its polypropylene shell eliminating cold bridges.
  • Very quiet - 25dB @50m3/hr and 30dB @100m3/hr and low fan power consumption puts it on top of the SAP list.
  • Uses the world's most efficient fine-wire heat exchanger, its 15 times more powerful than a standard plate heat exchanger.

A 200m2 Passive House without HRV has 5,500kWh ventilation losses, always on ducted HRV reduces these losses by 3,500kWh, costs £96/annum to run and £60/annum for filters. This leaves £200/annum savings to pay back the £5,000 capital cost plus mortgage interest leaving a payback of 40 years. It probably needs replacing every 25 years!

2 FreshR units in the 200m2 house reduce the ventilation losses from 5,500kWh/annum to 500kWh/annum because unoccupied areas aren't ventilated, because they're always balanced and because the powerful heat exchanger is 16 times more efficient. There's no filters and the combined running costs of 2 units is £5/annum. This leaves £500/annum savings to pay back the £3,200 capital costs leaving a payback on investment of 8 years.

FreshR's intelligent controls with CO2 and humidity monitors continually balance fan speed for optimum efficiency, compensating for wind speed and air quality, this improves the heat exchange efficiency by a further 10%. (In a Canadian ducted HRV field study, 46% had unbalanced supply and exhaust air flows), so the FreshR units only start when stale or humid air is detected, this ensures optimum air quality and eliminates unnecessary ventilation heat losses.

Centralised HRV systems use filters to reduce dust and grime building up in ducts, but often the pipes between the filter and the room remain dirty! (In a UK study only 10% of HRV owners changed filters, a Dutch Health Dept HRV spot check showed 52% had dirty filters). Despite 15,000 HRV units sold in the UK in 2011, only 2,000 filters were sold in 2012.

FreshR combines the best heat exchanger in the world, with the most efficient EC fans in the world, with intelligent controls that constantly adjusts fan speeds, add in its ability to only ventilate occupied areas and it becomes something remarkable.

The slim-line design of the breathing window means it can be installed into the wall with just a sleek panel visible. This panel is easily opened for maintenance and cleaning.

Behind this door, the smart controls of the system monitor the temperatures of the 4 air-streams in the unit. The system will always run itself to maintain the highest level of efficiency while ensuring CO2 and humidity levels are regulated using sensors. When CO2 reaches 1,000ppm or humidity reaches 50%, the unit automatically slows down to trickle speed until levels become higher again. At 50m3/hour, the breathing window emits just 23dB of sound, while at high-speeds of up to 100m3/hour this increases to just 30dB. This is indistinguishable from normal household background noise.

Cross ventilation above and beneath doors is crucial in all Passive Houses with ducted HRV, and often under-estimated at the design stage, not so with the Breathing Window. With subtle architrave ventilation detailing, threshold gaps and ventilation grills in bedrooms to cross-ventilation zones, we ensure gas equalization throughout the building, with typically 2 units acting as the lungs of the house. One unit running at medium speed (100m3/hr) provides enough fresh air for 4 people (Passive House requirement are 25m3/person.hour).

Due to the small dimension of the heat exchanger and the rapid temperature drop over 16mm, most moisture leaves the building as saturated vapour, which means less frost occurrence and less defrost cycling compared to standard units of similar efficiency. A FreshR unit tested in Iceland had a 95% lower defrost cycle rate than standard HRV units.

This detailed Zero Carbon Hub report highlights many of the problems experienced with Ducted HRV, section 7 makes interesting reading. The plug in and play, self adjusting FreshR without filters and ducts solves all of these problems.

Here's the Vaventis Brochure and Order Form.