Inexpensive, efficient HRV?
ranson
| Posted in Mechanicals on
I just saw the posts about the Panasonic Intelli Balance 100 ERV. Does anybody make a similar HRV? Something with a price point under $1,000, good efficiency and at least 50+cfm airflow? A unit like that would make me reconsider an exhaust-only system.
The closest I’ve found are the Braun HRV160 ECM units.
–John
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Contact Panasonic, I believe they also make a HRV core. Failing that, Home Depot got a HRV for $500.
The LifeBreath units might work for you. The 95 MAX and the 100 ECM are under $1,000.
John,
For applications where a Zehnder HRV is too expensive, you might want to consider using a Renewaire ERV.
You can buy one online for $728.
http://www.ervdirect.com/shop/energy-recovery-units/renewaire-ev90/
http://www.hvacquick.com/products/residential/HRVs-and-ERVs/Residential-HRV-ERV/S-P-TR-Series-Energy-Recovery-Ventilators-for-All-Climates
Martin, the Renewaire EV90 is a better value, at just over $600...same core, much more efficient motors. The S+P TR90 is the same product, available through other online retailers.
As far as sub-$1,000 HRVs go, I'm not much help...
Thanks, John.
Ultimate Air makes a 80CFM ERV that sells for a little above $1k
It sounds like the conclusion is nobody makes an inexpensive, good HRV.
--John
I'm planning to install 2 Panasonic IntelliBalance 100s in my house now under construction.
To be clear, I am specifically looking for an HRV.
--John
Richard, Will you be installing them yourself, or having someone else install them for you?
Richard,
Did you consider the Panasonic WhisperComfort ERV? If so, why did you choose the Intelli Balance?
When it comes to ERV vs HRV, I believe there really is no difference between the two when it all comes down to it. I believe it is better to find a good unit, whether ERV or HRV, and there is little importance as to whether it is an ERV or HRV.
I want to be able to rely on my ventilation to remove moisture from bathing. Good ERVs return 70% or more of the moisture right back into the house. That's why I want an HRV.
--John
John, a study published by NRC found the overall performance of ERVs to be much better than HRVs even when considering the small spikes in returned humidity during showering. Perhaps some of the more experienced members could post a link?
In another study done in Quebec, a large number of homes outfitted with both HRVs and ERVs were studied. In colder months it was found the ERVs could be run for much longer with less lowering of indoor RH. ERVs also tend to need less help from defrosting circuits in cold climates.
Here's a link that deals with some of these concerns:
https://www.dpoint.ca/erv-or-hrv-in-cold-climate-zones-time-to-end-the-debate/
That link is to a manufacturer site that sells ERVs so take it with a grain of salt, but it generally agrees with published studies.
For ERV, it's starting to look like the ev90p is a much better product than the intelli balance 100.
If you're always running 90CFM, the specs are better.
EV90P @ 90 CFM, 32F: SRE 80, 44W
FV10VE1 @ 86 CFM, 32F: SRE 75, 54W
However, the Intelli-Balance 100 has independently controlled ECM motors that allow balancing and operation below full speed. It doesn't look like the EV90P even has balancing dampers.
--John
Nobody's mentioned Venmar. Made in Canada, Energyconscious.com sells various HRV models under $1,000 that would fit your specs. Mine's been running fine for three years.
I haven't mentioned Venmar because they're sold as Broan in the US. For instance, the Broan HRV160 ECM is a Venmar 15 ECM HRV.
--John
Looks like a Lifebreath RNC5 HEX TPF or RNC5 HEX TPD goes for about $700 plus shipping. They're not quite as efficient, and they require external balancing dampers. The SRE is still 72-77% and the CFM/W is 1.53-2.26. There are also various controllers available.
--John
Lance,
Data is good! Can you point to a study that looks at the effects of HRVs and ERVS on the relative humidity of well-sealed and insulated structures during winter?
--John
Just heard back from Panasonic. They do not make an HRV replacement core for the Intelli-Balance 100 units.
--John
This link was on a newer post on GBA.
It posts specs for many HRVs and ERVs.
Use a Zhender model as your comparison.
http://www.phius.org/Tools-Resources/Protocols-Calculators/HVI-Winter-Ratings-modified-for-PHIUS-modeling_June2016.xls
But there is no cost comparison.
John, the forum is blocking my post, likely due to the link I'm trying to include. If you Google "Residential energy-efficient moisture control through ERV" it should be the first non-ad that comes up.
Quote from that page:
"Summary of findings
NRC studies indicate that in certain climates, ERVs can perform better than HRVs. In cold and dry climates, ERVs are effective in preventing indoor dryness by retaining indoor humidity. In warm and humid climates, ERVs provide better humidity control and reduce the electricity consumption of air conditioning systems or dedicated dehumidifiers."
Now, to include the vast experience of the members of this site (as I've read it) as well as your comments regarding "well-sealed and insulated structures during winter", I'm sure at some point as the house gets smaller and better sealed and the amount of moisture introduced by the occupying family increases, there will be a crossover point at which the concern will switch from retaining moisture to evacuating it. However, my gut tells me the AVERAGE house in a cold climate will tend to fall on the side of needing moisture retention, hence will benefit from using an ERV instead of an HRV should ventilation be required (it IS required in the building code since 2010 IIRC).
To be clear, I understand that BOTH ERVs and HRVs will exhaust moisture in cold climates, just that the ERV will exhaust LESS than the HRV and will therefore be able to provide a higher rate of ventilation for a given level of dehumidification.
With regards to summer performance in hot humid climates, I'm making the assumption that the 12% reduced energy consumption from the air conditioner was mostly to do with a reduced latent load, allowing it to work more on sensible cooling of the house.
Specific to your point about removing moisture generated by bathing, another quote:
"The study also showed that there is a small potential for ERVs to introduce some bathroom moisture back into the house for a few minutes per day under certain conditions. However, the benefits of the efficiency in continuous pre-cooling and pre-dehumidifying of the incoming outdoor air and control of humidity throughout the house on a continuous basis are overriding this effect."
The test was done in the Twin House project here in Ottawa, and we do get very humid weather in summer. I would also assume that the more humid the outdoor conditions the bigger the advantage of the ERV, so less humid climates may see less difference.
Lance,
I'm sorry to hear that you had trouble posting the link. Here is the link:
Residential energy-efficient moisture control through ERV
-- Martin Holladay
So, Martin. It would be great to hear YOUR point of view on the relative value of ERV's vs HRV's in a colder climate. Here in Minnesota, I am trying determine which to buy. Before reading the above I was totally convinced I should get an HRV, mainly because of my general understanding that ERV's were targeted toward's the southern states and lots of humidity removal during summer months. I did not realize that , in fact, they can be helpful in winter months up here in the upper Mid-west in RETAINING moisture. This is a great find from my perspective. I have a simple balanced exhaust, no heat / moisture recovery system and find that my humidity is in the 20's to low 30's in the winter. Continuously getting static shocks. (The cats don't like to be touched often because it comes with this "shock"! Ha!) I will not even use the ERV / HRV in the months April thru Sept because we often leave the windows open. Even planning a whole house fan to supplement during humid days/ nights. The mini split hardly ever is used(for AC) except when we close the whole house up in June or July for about 3 total weeks when we get Florida weather. It would be great to get direction so I can focus on ERV or HRV. . . thanks! (PS Looking at Renewaire EV90 or 90P or a Broan alternative. . . notice that Renewaire does not even OFFER HRV's, their TOTAL solution is ERV!)
Brian,
My analysis and advice can be found in this article: "HRV or ERV?"
Well, I finally made a decision. Chose the ERV. Specifically, the Panasonic FV-10VEC1, cold climate ERV. It was half the cost of the Recoupaerator ER80M‐E and only 1/3 cost of the 200DX‐E https://www.ultimateair.com/product.
Here is why:
I am cheap. I only have two equally sized blowers supplying / exhausting fresh air to my home now. I want the heat exchanger to PAY for itself in a few years, not decades. Initial cost being low is therefore, important!
I like not having to mess with a drain, no drain on ERV's since they move the moisture from one stream to another instead of dumping it; This unit appears very well engineered, high efficiency, dampers for good control, variable speed ECM motors, easily programmable, good manual, International name brand. Oh, and one more important thing: per anon3's end note below: " . . . only the Panasonic unit is designed for proper filter loading up to .5" and still remain balanced. "
Some things learned about ducting recently: If using flex insulated, stretch it out to full 25 ft lengths and use in straight lengths only OR its possible to double delta P as it increases friction factor exponentially(Ok, slight exaggeration)-- as it sags or shrinks in length; use galv. duct as much as possible to prevent high duct pressure drops. Crazy as it seems with such small flows I will very likely use some 8" duct here. Thanks to all here, specially Martin, for your insights!
Much appreciated, Martin!
An afterthought... John, perhaps Panasonic is aware of the benefits of an ERV over an HRV in most climates and that is why they don't offer an HRV version of the new Intellibalance unit? If there are advantages to an ERV in hot humid climates as well as cold dry climates, as long as the sensible recovery performance was competitive with HRVs then I would see no benefit to offering an HRV version.
Martin/others, are there specific climate conditions where an ERV has been proven to be less effective than an HRV, or detrimental in some way?
Lance,
In my opinion, the differences between an HRV and an ERV are often exaggerated.
In case you haven't seen it yet, here is a link to an article on the topic: HRV or ERV?
-- Martin Holladay
ERV doesn't have a drain, HRV does, anything with a drain has extra potential for biological growth.
What do the various prices people are quoting include? Presumably they don't include installation or commissioning.
I'll start by saying that I've been convinced to go with an ERV.
Is there any actual research that says that HRVs have greater potential for biological growth? I would expect that a moist ERV core could potentially harbor microbes.
--John
Stephen,
All of the prices that I'm looking at are retail, sans external controls and installation.
--John
John, I am in a steep learning curve with regard to all things Building Science related. While I have provided what I believe to be some credible information on ERV vs. HRV considerations, I won't pretend to be an expert and certainly value the input of the more experienced members here.
Martin, yes I read your article and it presents some very good information. I completely understand the "it depends" conclusions as well.
Having said that, if an HRV and an ERV both had comparable sensible heat recovery performance, similar airflow specifications and fan efficiency, and similar costs, can you suggest a scenario where the ERV would NOT make sense to install? Your article mentions a scenario in hotter climates where outdoor air is sometimes less humid than indoor air and this could potentially hinder the ability of an ERV to evacuate moisture. Would this be a case where the year-round considerations would lean towards an HRV over an ERV? Would this scenario be one that should include a separate dehumidification strategy to control moisture instead?
There are ERVs with auto bypass mode if outside is more favorable than inside, Panasonic got one for sale in China, not in US though.
Excellent point, NA, I forgot about that.
My vote after much research is still with John on the Venmar E15ECM/Broan HRV160TE (model number, also listed as model name HRV160ECM). I found it available online for about $1000, and for my 1500 sq.' home in Zone 5 it seems like the best performance bang for the buck, with low electrical use ECM motors. I'm placing my order tonight. The next larger new model that they have is the HRV200ECM, which is slightly more efficient, and significantly more expensive. For my 45-50 CFM, the HRV160ECM will be fine.
No spec for cooling. Also, note the fan curve, as the outdoor filter is used up your house will be negative pressure, only the Panasonic unit is designed for proper filter loading up to .5" and still remain balanced. They really should advertise this point more. What's the point of ERV is it's going to be negative pressure most of the time in real usage.