I've seen the Vents US "Lunos " clones mentioned, but I have not seen talk of the Vents Micra 60:


http://vents-us.com/images/cat/664_243_cat_file.pdf



http://vents-us.com/cat/664/

If I am understanding correctly, the Vents "TwinFresh" would not be balanced unless you had two units (intake and exhaust simultaneously like the Lunos).  Looks like the Micra would be balanced.  Is this a suitable system for a small household?  I guess the main disadvantage is that it's drawing and replacing air from the same spot?

Any thoughts?

I believe that if interior doors are left open, sufficient mixing will occur in almost all houses. With closed doors, some extra flow through the HRV (ie, the main space is slightly over ventilated) + a small up-high vent + the under-door gap might be adequate. Given the cost of putting a ventilation supply and return in each closed door room, it's worth investigating.

IMO, non balanced systems (eg, a ventilation supply but no return in a closed door room) are a bad idea.

jonr- if the TwinFresh was used in place of an HRV, as I think the OP was asking, where would the mixing flow come from?

There is always some passive mixing circulation and only a few CFM are needed. I don't like the TwinFresh idea of pressurizing and then de-pressurizing the space - that's a good way to increase in/ex-filtration.

Hi... I just joined to participate in this thread

I've been researching this for a couple years now and only recently did I come across single room HRVs offered in North America (aside from Panasonic's FV-04VE1 ERV). So I've been looking into Vent-US''s Micra 60 and TwinFresh systems, as well as 475's Lunos e2.

With a single TwinFresh, I agree that pressurizing and depressurizing is not a good idea. As well, agree that with a single TwinFresh I'm not convinced you'd get decent mixing throughout your room given intake and exhaust is from the same spot.

As for the Micra 60, I believe it will provide good circulation the exhaust sucks air in horizontally and the intake blows fresh air straight up (good convection)... unless you have more than one room. I'm hesitant to go with the Micra 60 since it needs to be mounted low on the wall and thereby consumes valuable space. As well, it is less efficient at heat recovery than the ceramic core types.

For my 400 sq ft condo with 1 bdrm and 1 bath, my plan is to go with a pair of Lunos e2, one mounted in living area and one mounted in the bedroom. Bedroom door will be undercut plus a vent up high with a 25 CFM silent 12V computer fan. This fan will be tied into the switch for the Lunos (also 12V) so it's running whenever the HRV's are running and will provide (additional) circulation within the small dwelling while the HRV's are push/pulling. I looked into available room-to-room (aka thru-wall) fans/vents but they all are pricey, louder, and overkill. I like the Lunos versus Twinfresh since the Twinfresh appears to have a giant box on the outdoor side of the unit, whereas the Lunos is just a discrete grille.