Old prototype, but working: https://www.tindie.com/products/adouglas/unique-energy-recovery-ventilator-prototype/
More recent prototype: https://www.tindie.com/products/adouglas/open-energy-recovery-ventilator-version-54/
The kits are here: https://www.tindie.com/products/adouglas/kit-3d-print-your-own-energy-recovery-ventilator/
The production models will be listed soon, in the meantime you can place orders for beta units, which are cheaper and work fine (you get a discount for being a beta tester ;-).
I have yet to get some boilerplate to make things legally binding and stuff, but the general plan is 60 days satisfaction guarantee, and 5 year warranty against defects in material and workmanship. However be aware this is partly why the units are not that cheap. If you make it from kit, you dodge the costs of this stuff, which I would like to encourage, as it makes the whole proposition even more viable economically.
But Open Source is better than any warranty, especially for the long term:
Unfortunately, planned obsolescence is not a conspiracy theory, and it has a major impact on the amortized cost of things. We’ve come to expect things to break soon after the warranty runs out, and not be economical to fix when they do. But a product that lasts 5 years is still 6 times more expensive than a unit that lasts for 30 years, per hour of operation. Open source hardware like the OpenERV doesn’t include planned obsolescence, so it can last far beyond the warranty period. All conventionally made equipment does include planned obsolescence, for sure, even if it’s a reputable brand. Open hardware is made to last as long as technology allows - although the sub-components like the fans, made in a conventional way, still have planned obsolescence in them, they are economical to replace when they wear out/break.
You can see how harmful planned obsolescence is even there - the reality is that fans don’t wear out, only the bearings in them do. The rest would last another 30 years, probably, if you could just replace the bearings for a dollar, but you have to replace the whole fan for $20, because that’s the way they planned it. Even solid state electronics don't last forever, but 30 years is a good bet.
In a unit like the lunos e2, the fans will still wear out after a few years, but when they do how will you replace them? They are highly unlikely to be standard, commodity fans that are easy to obtain. In fact, I searched high and low for suitable reversible axial fans when trying to design the OpenERV, and could find nothing, even on Alibaba, etc. Will they even sell you just the part so you can DIY or do you have to pay huge amounts to get it done by them? Will they still be in business? Is the thing even possible to disassemble, or is it all glued/riveted shut? With open source tech, you don't have those problems.
Artisanal manufacture may give one pause, and concern for the quality of the product, fairly enough, however, artisanal production does have a long and successful history. We are also so submersed in the serious downsides of conventional approaches, we tend to forget to consider them, too. We are like frogs in boiling water. We just assume that a product won’t last longer than the warranty period, and when it breaks after that, it will be impossible to fix. Open source hardware isn’t like that.
Could an OpenERV could “last” - that is, with maintenance - for 50 years? I don't know. With every part always inexpensively replaceable, how do you even measure such a thing?