SEVi Ductless HRV-Systems

How does a decentralised HRV System work?



In modern homes, the use of mechanical ventilation systems has become essential because there is no sufficient air exchange on a natural way anymore due to the airtight building sealing.


It´s important to have a well insulated and airtight home to save energy, but without a proper ventilation system you´re increasing the risk of stale air, dampness, mould and allergies in your own house because there´s no escape for the moisture.


The SEVi HRV System operates as a ductless mechanical ventilation system with heat recovery. It doesn´t need extensive ducting like conventional HRV systems.

Approved and certified mechanical HRV System

Benefits for the use of ductless SEVi HRV-Systems:

  • easy installation, no extensive ducting required 
  • no penetration of airtight & vapour control membranes
  • low energy consumption because of low Wattage units
  • easy maintenance, no specialists required
  • high heat recovery performance (up to 90%)
  • a dehumidification effect for your internal room air
  • a certified system, engineered and manufactured in Germany
  • more than 13,000 units have been sold in Germany and operate without complaints


How does it work?

All SEVi HRV-Systems work as ductless Heat Recovery Ventilation Systems. They have no need for separate ducts and pipes. This is due to every single unit being equipped with it´s own heat buffer eleminating the need for additional ducting or suspended ceilings in your house or to hire specialists to clean out the entire system on a regular cycle.


Depending on your room size you may need only one set for the area you wish to ventilate. The units are fitted to an exterior wall and operate in synchronisation with each other. One sucks in fresh, clean air whilst the other one blows stale air out of the room and they then switch function every 75 seconds using the heat from the expelled air to warm the fresh incoming air.


The heat recovery performance is up to 90%, which means the stale air leaves the room with a temperature of 20° Celsius and the fresh air returns into the room with 18° Celsius. Compared with other ventilation strategies (opening windows, trickle vents, DCV), you´ll save heating energy and money because the incoming fresh air is already preheated.


SEVi ductless HRV-Systems are easy to install and maintain. Every HRV-Unit runs on 12V DC and all required maintenance can be done by yourself. For example - the heat buffer is built for cleaning in a domestic dishwasher. And there´s no risk of cultivating germs and bacterias in hard-to-reach (and hard-to-clean) ducts and pipes.