Smart air vents

Tim, just be sure you don’t harm your HVAC system. I’ve done a fair amount
of research on this topic since originally looking at the vents, and it
appears that the various pressures and backpressures in a system are indeed
of critical importance.

Jerry Hatchett, CCE, EnCE

Certified Computer Examiner
EnCase Certified Examiner
Licensed Private Investigator (Texas PSB License #A18333)

Omni: 713-364-2467

DISCLAIMER: Anything I say, particularly with regard to technology, should
be interpreted generally, not specifically. The online world is a wonderful
thing, but rarely is it practical to cover every imaginable scenario in a
written, fast-paced forum. There are often exceptions, so keep that in mind.

Here is a question for everyone who follow this. With the smart vent (Wifi control), to me it doesn’t make sense as I don’t really play around with temperature setting everyday. So for my use, I just want to program the room as what I normally do with the house thermostat (lock at 70°F all day due to stay at home wife) then never have to look at it again. For this, it does not justify to pay extra money for the Wifi control system that I don’t play with the setting everyday.

That being said, I’m a homeowner of a 4 rooms (colonial, 3 girls) in Michigan. Two of my daughter’s room facing south, so in the winter time it’s always hot when the sun came out but fine without the sun. I have made an automatic vent open/shutoff using a $3 Arduino Nano, $3 servo, an el cheapo thermostat and a 5 volt transformer (old cell phone charger). This have been working great in one of my daughter’s room and I’m planning to do a few more for the other rooms. With less than $20/room I think it’s great on a lot of ways. Not cooking my kids in their own room is the biggest factor of this project but also a low cost project and potentially save money on heating and cooling in the long run. The money saving was not what I planned. It’s the safety of my kids is what I’m after. There were a couple times that my kids woke up with bleeding nose as it was too hot in the room while they were sleeping.

If anyone feel offensive please don’t as I’m just asking for everyone opinion regarding the WIFI control as I have seen more and more coming out in the market.

This thread has a great amount of detail that’s really helpful. I have a similar question, except it’s a little different in that I’m starting from scratch.

I recently purchased a house with four very small efficiency apartments. The apartments are supplied by a common residential HVAC system. As the landlord, I pay the utilities. The units are very small and each has what appears to be a single 4x12 heating vent (although I need to research this further). I’m looking for ways to minimize my utility costs without sacrificing tenant comfort. As a starting point, I thought about putting in a smart thermostat with time of day controls and a system to monitor temperature in each unit. However, this could quickly start to cost money and I’d like to move in a direction that I could expand into a more capable system.

The total solution that I’m looking for would ideally:

(1) provide remote monitoring and control, via internet (preferably via wifi),

(2) give the ability to install a temperature sensor in each unit and track temperature by unit over time

(3) provide the ability to install a smart vent in each unit and intelligently control the smart vent centrally via programmatic rules

(4) Give ability to link sensors and vents to create HVAC zones (one zone for each unit in this case)

(5) Provide the ability to slightly limit airflow to units without totally shutting off airflow (I wouldn’t want a computer program to decide to shutoff all vents except one then fire up the furnace possibly damage the HVAC system… a system of detecting high pressure at the vent and opening the vent when pressure is high would also be good),

(6) At a minimum, the ability to adjust vent volumes somewhat to maintain constant heat across units,

(7) A simple user interface (web browser with temperature by time of day is ok),

(8) The ability to automatically get all of this to work together to maintain a separate custom temperature schedule in each unit (nice to have),

(9) the ability to slightly reduce heat / cooling to empty units based on motion sensing (nice to have),

(10) booster fans in the vents that can be used to increase airflow at vents that have lower pressure (very nice to have)

(11) the ability to set custom rules around running the blower fan on the HVAC system to redistribute heat is also a great idea

(12) Finally, the solution needs to be reasonably affordable (under $1,000 for everything, preferably under $500), and be sufficiently reliable that I don’t worry about it running on its own a couple miles from my house or constantly need to drive over to tinker with it to get it to work

Thoughts and advice are definitely appreciated.

Yep, we like it. Of course, your system would have to be configured such that its optimal flow is not impeded by the controls, but merely redirected.

I use aeotec micro double switches to control boosters and dampers within my hvac system, have used it since March of this year and saved quite a bit. Granted I used in conjunction with multipurpose sensors (for temp and window monitoring), presence , motion/occupancy, along with virtual thermostat to have the a.c. or heat essentially follow us. It wasn’t very much work it wasn’t very expensive ( 6" booster is $29, damper is $69, double microswitch to control 2 or 1 booster and 1 damper $40)

You could

  1. Put a thermostat in each unit with temperature lockouts and have the boosters and/or damper control where air went

2.Use virtual thermostat that uses temperature sensors in all of the units and balanced with the dampers/boosters

  1. A slight variation of 2, to give tenants more control use minimotes or similar to raise or lower temperature ( they would open/close damper or turn on/off booster)

I know that worked out for me and was very cost effective. Its not difficult to set up and there are quite a few smart apps that would work depending on which way you want to go with fairly simple user interfaces

Totally agree with you on this. One of the reasons why I didn’t go this route yet. I think one way to solve this is if each zoned dampers are working in conjunction with their own dedicated emperature sensor in the rooms they are heating and cooling, and then have a variable speed furnace set to turn off and on based on readings from the temperature sensors. Really, you will be controlling each individual rooms temperature on your controller (smart app) than the thermostat itself at this point since I don’t think any thermostats is capable of proper zoning.

Yes, and there is already a smartapp for that!

There are many safeguards in my smartapps to avoid closing too many vents at once.


Thanks for pointing this out chrisf.
Here’s my solution and recommendations:

For existing systems, chrisf is absolutely right that the duct sizes are (if engineered correctly) sized for the furnace BTU for proper airflow to take heat from the furnace heat exchanger at the right rate. If airflow capacity is decreased by closing air paths, it makes the fan work harder and the system much noisier, and risks killing the furnace.

Newer modulating or staged furnaces usually have proprietary thermostats and controllers that can handle zoning and pressures, and many communicate by Zwave or something else compatible with SmartThings. There might be enough information from those to inform control of smartvents through smartThings as well, but it’s a risk if the ZWave communications go down. Proprietary zoning is the best option for sure, but I hate the look of what’s available, and I love to tinker, so I made my own.

I just put in a new 98% efficiency, fully-modulating furnace with two zones on a standard single-stage thermostat and custom zone controller (which defaults to one zone with all zone dampers open), and I am planning one smart vent for a guest room. The way my York modulating furnace works is that it starts out at minimum heat (~40%), and fan speed is automatically set to maintain the proper static pressure and airflow for the heat created. After 10 minutes if the thermostat is not up to setpoint, the furnace (and fan) start ramping up over 20 minutes to 100% until temperature setpoint is reached.

Since my fully-open system is built to handle 100% heat, I’ve set up the zone dampers so that 40% is always OK, and depending on the zone(s) calling for heat, I open first the calling zone, then ramp open the other zone as needed over the 10-30 minute period. I plan to put in static pressure gauge to help control the dampers in the future. Since the planned ZWave smart vent is on a single small branch, I feel safe to run it through the ZWave network rather than the furnace controller, as even if Zwave communications break down, it won’t kill my system. But I wouldn’t count on ZWave coordination with furnace or thermostat for more than 10% of the duct area.

Here are some explanations about smart vents vs. traditional zones. Each solution has its list of pros and cons.


I see in the keenhome site that the ‘auto-balancing’ feature is marked as ‘coming soon.’ Is that intended to be some sort of zone controller that communicates with the furnace to modulate staging and help with minimum airflow to protect the furnace? I’m sure the company is concerned about damaging expensive furnaces, so can you tell me something about how they are addressing that issue?


I’m not from Keen Home, but I’ve worked with them to develop my smartapps.

I’ve implemented many safeguards to avoid closing too many vents at once as stated here:

And, you can refer to their website about your questions:

Look under Smart Vents> Smart Vent Basics.

Will closing vents harm my heating and cooling system?

Closing off a couple vents in your home won’t harm your system, but we don’t recommend closing all of them at the same time. Rule of thumb: always leave at least one vent open at all times.

EDIT: I’ve had 16 vents for more than a year now with no issues… With my smartapps, you can configure the “closing” level which should be at least 10-20% outside of your active zone(s).

If you have few smart vents with a lot of dumb vents, of course, the “closing” level could be closer to 0…

Ah very cool. I knew someone had already done this, and glad to get your reference.
So the Keen vents have proportional control eh? Nice. I’ll look into that and your app.
Is there any accommodation for when the Hub goes out, which it does occasionally?

@scheerd, no, there is no accomodation of that nature as it’s not possible to do anything after the hub goes offline, and there is no advance warning of any kind for any ST hub outage.

The vents would then be left at their last state till the hub goes online again.

I’ve not experienced personally any major hub outage since I got my hub more than 2 years ago. I must say that I’m still on Hub V1 as there were no major incentives for me to upgrade to V2.

Maybe, you have some internet connectivity issues?

I’ve had no major issues, but for mission-critical stuff like HVAC, it’s not 100% reliable without a wired connection and backup power. For example, though my door open/close sensor works 99% of the time, it has left my lock open, or opened it automatically thinking that the door was open when it was closed and I was away, so I now don’t allow it to unlock when it thinks the door is open.

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Sorry to revivie this old thread, but does anyone ( @EcoNetBlake ) know if EcoNet is every going to manufacture their Smart Vents again? Their site always says they are “Coming Soon” which seems odd since I believe they were available in the past, right?

Thanks for the note.

The beta version of the EV200 (Gen II Smart Home HVAC Vent) in the 4x10 size will be available to advanced users in September.


The Smart Gate Lock is in development with a beta unit expected this year.

Production versions of both the EV200 and the Gate Lock are scheduled for 2018.

I have often wondered about supply vent fans. I have two vents in my home, both on the top floor, that simply don’t get enough air feed from the basement-dwelling heating system.

In my ideal rendition of control of forced-air, I would

  • have baffles as close to the heat source as possible
  • have fans as far from the heat source as possible

So that if the office hits its desired temperature, the system closes the baffle on the office duct right where it segments out from the main feed. Meanwhile the top floor bedrooms ‘pull’ the warm air up and into the room, thereby helping the main fan do its job.

I moved home and now have no need for a bunch of my Keen SmartVents. I have:

6x10 = 5
6x12 = 3

Anyone interested in making me an offer?

Does your vents have fans in them to boost airflow? Or it’s just an on / off zwave control?

EcoNet’s Smart Vent project is on hold. The smart vent does not include a fan.
Details on the most recent smart vent design are available at:
Please check our page for new product details and updates.