Experience with Lunos Fans
JennL
| Posted in Expert Exchange Q&A on
Does anyone have experience with the Lunos e2 HRV or the Lunos E-Go HRV fans? I’d be interested to hear your experience with them. I’d also like to know if you’ve had any problems with mold on the ceramic cores? Thank you.
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Hi Jenn,
We have installed at least two dozen or more of these HRV's over the past decade or so and even have them installed at our company office. They are great units for certain applications. They have a great sensible heat recovery efficiency (around 93%, I believe) and can be installed in a through-wall application avoiding the need for a large unit and ducting. They aren't ERV's so they don't deal with returning some of the latent (humidity) loads and in some circumstances could lower the indoor RH which is good or bad depending on your climate/circumstance. They tilt slightly towards the exterior so condensate can run out via the PVC sleeve that the cores and fans sit in. They are easy to install and require a low voltage connection between the two.
One limitation is that a pair will serve 600 sqft, so for larger buildings you may have to use multiple pairs which, when one adds up the costs, can be as much or more than a stand alone ducted unit. They really shine in small buildings such as Accessory Dwelling Units or small apartments. They can also be a good solution for retrofits when there isn't much space for running ductwork.
One thing to note is that the units require about 11" so if your wall isn't that thick you will either have to create a bump out on the exterior or box it in on the interior to make up for this. We usually elect to go to the exterior when building without exterior insulation and use a large block and flash it into the WRB/rainscreen/siding.
They also have a noise... Not a loud noise, but one that starts and stops every 90 seconds or so as the fans reverse to either bring in and condition outdoor air or exhaust indoor air and charge the ceramic core. Due to this I would highly recommend not placing these in a sleeping room or bedroom if possible. It is one thing to have a constant white noise, but another to have it start and stop while sleeping-- no matter how quiet it is.
The filtration on the units isn't anywhere near what one would get with a dedicated system. I think they go up to a MERV 7, whereas some of the other systems will get into HEPA territory and up to MERV 15.
I haven't seen any mold issues in the cores. We recently went back to a project where we installed these about 8 years ago and beyond needing a good cleaning (all HRV's require regular filter maintenance) they were working fine with no mold. The units at our office are about 3-4 years old and I am unaware of any mold on those units, either. We live in rainy Portland, OR so we see our fair share of moist air.
Overall I would recommend them for the right situation and we do continue to spec them when the right opportunity arises.
Thanks for the information.
I noticed that a MERV 13 filter is now available. We are considering using them for an 1800 sq ft ranch so we would need 3 pairs. Do you think that is an appropriate application? I'd like to avoid a ducted HRV/ERV due to the risk of mold growth in the unit.
In terms of cleaning, did you vacuum or replace filters? Did you clean the ceramic cores, and, if so, how?
And do you notice any exterior noise coming through the units?
Thank you
Jenn,
I went over to the 475 supply site and indeed see that Lunos is now offering a MERV 13 filter option. They also offer some sound reducing options, too. I don't have any experience with these, but great to see that Lunos has these options available. One thing to note is that the filters (and potentially the noise reducing products) will likely create a static pressure and will likely reduce the stated 20 cfm down some. You will want to make sure that you are meeting the required ventilation for your home with the lowered cfm's. This may bump you up to 4 pairs to meet the requirements.
We wash the filters in warm water, squeeze them out and let them dry. The core and fan just get vacuumed and wiped down with a damp cloth.
One can hear exterior noise through the unit, but we haven't ever had it come up as an issue from our past clients, nor have we had issues at the office.
I wouldn't rule out a ducted system for an 1,800 sqft home. Is this new construction? There are distribution, noise, latent, aesthetic, smart balancing and other benefits to using a dedicated ducted system. I also wouldn't rule them out due to mold growth-- I have yet to have heard of that issue (on a continuous ventilation device) and we haven't seen that be the case on any of the ducted units we have installed over the last 12+ years. One does see algae grow on the condensate drains, but that is an expected maintenance issue.
I would consider comparing and contrasting a dedicated and ducted system. The Panasonic Intelli-Balance unit is likely in the fight based on the cost of 3-4 Lunos systems including the filtration, sound dampening and installation costs.
Thanks for your feedback. I'm very hesitant on the ducted H/ERVs.
I know of several reputable mold inspectors that caution against them due to mold growth in the cores. The temperature differential between air streams could certainly cause dew point condensation and while the cores can be immersed, the interior cannot be accessed for cleaning by mechanical means.
I've got to take the most conservative approach due to mold sensitivity. I've not heard of any mold issues with the Lunos cores at the time of this writing.
We've had ours since 2013 and love them. 1,200 sq/ft home and did only one pair. Works just fine but I have a super insulated house at 0.45 ACH. You don't want them facing a busy street as you can hear traffic through the filters. Very quiet that you won't notice them. They change direction every 70 seconds. I added protective blisters on the exterior for cold northern high wind protecition that could override the fan. Even at -20F they did not freeze up but had a little frosting. We live near GB wisconsin (go packs) so when it is -20F we still have 80% humidity due to Lake Michigan. I've installed 4 pair at other deep energy retrofits I've built. Owners like them.
Thank you for your response.
Where do you get the protective blisters?
Have you removed and inspected the cores - and no mold despite the constant humidity?
Would you advise avoiding placing one in the bedroom due to fan noise?
Thank you
The standard Merv-3 filter is washable, while the Merv 9-10 is not (only weak vaccuming and replace). I don't know for the Merv-13.
The unit's noise when switching direction is not noticeable at low speed (unless within a few feet), but really noticeable at high speed
Thanks for this experience regarding noise.
In the country without street noise, and no hvac on, would it still be inaudible on low?
The peacefulness in quiet here is a clear design consideration so I'd like to preserve that.
Thanks,
s
We do pull the cores once a year come spring to make sure they are clean. No mold. We shut the system off April through October as we like all the windows open. The blister/wind protection I built from leftover PVC (fake white wood)cut offs.
Thank you. Any chance you could post a photo?
Another option would be to use the new ComfoAir 70 from Zehnder.
https://www.youtube.com/watch?v=UWI2sQJW_vA