Fresh outdoor air all year round.

The TW4 decentralized Energy Recovery Ventilator transfers clean outdoor air inside and moves polluted air outdoors, while harvesting ~90% of the heat energy - so you get fresh air without the downsides of heating or cooling it.

The WM12 is basically two TW4 modules side by side in a piece of tough polypropylene foam, so you can put it in a window.


The design is now in beta. Listings will be displayed in the store as they become available.

Other details include: