Keen Smart Home Vents

Great questions:

  1. We track pressure and temperature in the duct via an embedded pressure and temperature sensor in every Smart Vent. If the pressure in the duct is between .5 and 1.4 iwc, the vents will automatically open enough to reduce the pressure. We also recommend leaving dumb vents open while Smart Vents are installed.

  2. You don’t have to replace the thermostats. Smart Vents work great on their own with standard thermostats. But if you to want to connect your thermostat to your Smart Vents, you can do so with Nest, thermostats on SmartThings (Yves Racine has built a Smart App that allows the Smart Vent to work with Ecobee), or a thermostat on Lowe’s Iris. We’re an official Works With Nest company and are also working on native Ecobee support.

  3. You can use a separate remote temperature sensor on SmartThings to augment the abilities of the Smart Vent, but you really don’t need to. We’ve been working hard on a controls algorithm that allows us to determine room temperature from within the duct, without needing a separate sensor.

Regarding your last point: that would be ideal for sure. It’s the long term idea behind Works With Nest. Nest thermostats support wifi, 802.15.4 (Zigbee), and Bluetooth low energy, so they could be a hub in the near future.

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Okay so with EcoVent they recommended replacing all the vents of which I have 17, the main reason being is that to help relieve pressure they could automatically crack the vents in non-critical rooms like the master closet/various bathrooms.

I’m really concerned about the back pressure killing my system and while it seems like EcoVent has really done their homework, I’m still really concerned about it so forgive me if I’m being over cautious.

I’m pretty certain that in my situation using smart vents is going to VERY quickly pay for itself via electricity bills, if you saw where the thermostat was in my house and what it has to contend with, especially living in Texas, I think you’d most likely agree.

Electricity bills of $250+ during the summer with only two people in the house aren’t uncommon.

You have every reason to be cautious, which is why we built in these safety measures. We do the same re: opening the vents slightly to relieve pressure. Our Smart Vents measure the severity of the pressure and adjust to reduce it. Hopefully we’ll be able to help you bring that electricity bill down!

What’s your view on replacing ALL of the vents (all 17 of them) vs. just some of them?

If it wasn’t for the fact that I’m getting a pretty sweet deal from EcoVent (plus a free Samsung tablet thrown in due to delays), you’d technically be cheaper even for the same amount of vents.

I’ll have to have a think about it, the ST integration is very compelling though EcoVent hoped to do the same.

It’s really up to you. You certainly can replace every vent in your home with our Smart Vents, but it’s not a requirement. Some homeowners just want to target certain rooms. We’re all about giving flexibility and choice, hence prioritizing integrations with platforms many homeowners already have (such as ST).

Hi Nate,

Actually, I have one smartapp, called ScheduleTstatZones, that can work with any ST connected thermostats whether zigbee, z-wave or wifi such as Nest or Honeywell.

There is another smartapp, called ecobeeSetZoneWithSchedule, that was exclusively designed to work with ecobee.

See my thread below:



I stand corrected. The point is, Yves is a rockstar and has built some incredibly cool integrations.

@Benji I would highly, highly suggest, NOT replacing all dumb vents with smartvents, regardless of the manufacturer. If you did, what happens when they all fail to do what they are told for a multitude of reasons? I know, I know, everyone builds a bulletproof system, but there will be a lot of handshaking going on to accomplish this integration with a lot of failure points. No one is going to pay to fix your furnance or ductwork for you.

If it were me, as I’m still on the fence on the efficacy of smart vents, I would aim for somewhere between 1/3 and 1/2 of vents replaced with the remaining dumb vents left for non-essential rooms at about the half open position.

All commercial and high-end residential systems such as this accomplish all of this with an included high/low pressure static safety switch that if tripped, shuts off the unit immediately. Most homes don’t have something like this.

If you or others need some sort of references on why I can make such a claim, I did embedded control systems programming/engineering for 5 years following college. It was all commercial and very high end residence, but the ideas translate 1:1 as it’s just physics and thermodynamics.

I’m sure most people that choose to replace all, won’t have an issue, out of luck, leaky ductwork, or what have you, but if it were me, I wouldn’t take that risk.

Also, as I am typing this out, an appropriate safety measure on a smart vent could be a minimum closed state of 10-15%. CFM output from a damper opening and closing is not linear though and for a non-educated consumer, if they saw a vent partially open still, they might think it was broke, so this could end up causing issues on the support front of the manufacturer.

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Some great points there!

How difficult would it be to retro actively fit a high pressure static safety switch?

The install itself isn’t difficult, it’d need to be hardwired into your furnance though. Chances are the hardest part is finding an adequate location. Generally you’d want it in the common duct after the furnace fan but often times ductwork splits off to other parts of the house quickly after leaving the furnance.

The safety would work best furthest from the furnace you could make it, while still being a common feed. “Furthest” here is operating under the assumption that you’re splitting off somewhere between 5’-10’ after the furnace. If you have some sort of loop system, then this answer changes.

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If it could be right next to the exit of the furnace then it would be easy since the water overflow shutoff is right there and will cut power instantly but since it’s better further away that would make it very difficult to retrofit.

So I guess I only should replace the grills that are in rooms that I care about, everything else be damned, that way I’m only trying to hit a target temperature of a small room rather than a VAST open space, I’m pretty certain it’ll save me money.

That’s the use case we have in mind (targeted temperature control in specific rooms), but whole-home works as well. We also recommend replacing at least 1/3 of the vents in your home with Smart Vents. @bmmiller brought up good concerns, which is why we built manual overrides into each Smart Vent. Every one has a manual switch that can be used to adjust how open or closed a Smart Vent is, just as you would do with a standard vent register.

We assure you that the Smart Vents won’t malfunction and leave you without the ability to control them from your phone, but if somehow they did the manual control ensure you aren’t SOL. Also, every Smart Vent intentionally leaks a little bit of air at all time to keep down the risk of excessive pressure build up.


Do you all have any studies or datasheets published showing effectiveness of your solution? Concept makes sense but would love to see some real world data before laying down few hundred bucks. Any SmartThings users beta test and have experiences to share?

We don’t have any studies just yet, but we will once the Smart Vents have been in peoples’ homes for a while. SmartThings beta testers have had their Smart Vents for about a month and a half, so not enough time to measure the impact of having the vents on their energy bills. But the feedback we have received is that the rooms in which the Smart Vents were installed were noticeably more comfortable than before the Smart Vents.

FYI, I have included the following safeguards into my smartapps:

  • The ecobeeSetZoneWithSchedule and ScheduleTstatZones (for generic ST connected thermostats) check each vent’s temperature and make sure that it’s within the minimum and maximum range to provide safe operation.

  • The smartapps check the ratio of closed vents/total connected vents and will ensure that the ratio is not higher than 50%.

-When the zone settings are applied, the smartapps ensure that there is a minimum open level for any vents inside the zone(s) scheduled at a given time.

Those safety measures are already implemented and tested with the beta vents that I have…

I will test again with a larger number of vents later when I receive the production ones…


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Hi! I do have couple of vents pre ordered. Any way that you can provide a status? This was almost 6 months back :smile:

I certainly can. Shoot me a private message with your order number.

I am interested in putting a few smart vents in my finished basement which is seldom used. Essentially im heating or cooling it needlessly along with my first floor since they are one zone. I would like an hvac industry authority (whoever that may be) to review your product and its safety for the home hvac system. As much as i like home automation, i dont want to kill my furnace for the sake of a hobby. Really this shouldnt wait until you get consumer feedback since most people arent educated about their hvac systems and can be raving about reducing heating or cooling bill or evening room temperatures while unknowingly damaging their hvac system. Its great that you have put in safeguards against pressure buildup but i need a fairly objecive knowledgeable reviewer (not just a tech enthusiast blog) to evaluate your system effectiveness and safety.

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I agree. It seems a little sketch that Keen Home has decided to wait on retail customers to provide case studies for both comfort distribution effectiveness and HVAC system safety. Presumably these vents have been installed at alpha/beta testers locations for awhile now and it seems strange that there is no data to release from controlled (heck even cherry picked) experiments to validate the safety and performance claims.

I sent you the information. Thanks!