I made a rant somewhere in this thread about the worthlessness of the pressure sensor in these vents, they went with an absolute implementation vs a differential one. a differential implementation would have had a reading of 0 with no airflow and gone up from there.
The readings are inconsistent, and do not have any practical value in determining the actual back pressure. I’ve seen lower values 5 minutes after the heat starts and then fully closing the vent, and this change isn’t mimicked across the other vents, even those on the same floor.
You can’t tell me that the air pressure changed that quickly in my house and varies that much from room to room. Floor to floor I get, the sensor itself is capable of that resolution.
So far no one has had any comments to contradict my comments…
so in other words there is no way to know if I am putting too much back pressure on the system. I have the vents (5 of 10 are Keen vents on this floor) set to close to 25% when the temp sensor in the room hits its set point. so Iguess that would be the same as closing 4 of 10 vents off if all of them were to close at once.
As far as I’m concerned, not without individually calibrating each sensor against a reference and including an offset in the device or smart app.
There is a very good sensor in there, I took one of these vents apart and looked the sucker up, I just don’t see how an app can make any definitive use out of it in the current hardware implementation, at least not enough to be able to track the max recommended back pressure, which I think is like 150Pa
Yeah if you look at @yvesracine discussion with their engineer, They seemed to suggest that the back pressure protection they advertise essentially won’t be possible without “their own system” which I presume to mean their hub. @NateKeenHome can you clarify on how Keen uses these absolute sensors to “ensure completely safe operation” as per the FAQ? Are those methods exposed to SmartThings or only available with the Keen Home bridge?
I can answer part of this, there are no additional capabilities that are part of the ZigBee device implementation that Keen’s hub is going to have access to in regards to pressure…
I’m very interested in whatever algorithmic magic they are going to apply to make up for the lack of a solid measurement…
Mind you, I like the vents, but the sensors aren’t of any real value as it stands at the moment.
Right the impression I got from Yves discussion with the engineer was that their hub has the super fancy logic that can use the absolute values in a meaningful way which they thought would be too hard (see proprietary?) to replicate in SmartThings
Of course the final statement is a little disconcerting as one would assume the whole point of having pressure sensors is to protect the system from comfort distribution logic that might result in all (or maybe even not all but too many) vents in a zone being closed…That is unless of course the sensors are meant more for marketing than actual system protection.
Yes, and it’s also possible to polish a turd…
There is no analytics that can fix crap data.
I believe the sensors are just barometric pressure and not airflow sensors. So they won’t protect your HVAC system as much as they can just monitor drops.
Be very careful in reducing pressure in HVAC systems by shutting off vents and starving your system. If anything, to make a system work better, you typically want to add output vents to the rooms needing air, not close off un-used rooms.
All HVAC systems are not created equal. Real monitoring would be done at the HVAC output and input points, not at an individual vent end point.
Is there an alternative device type available somewhere for keen vents. If yes, then can someone please direct me to it?
Hi,
Based on my interaction with the Keen Vents engineer who designed the ST stock device type, I created an alternative one which does not poll as often (mine polls every 5 minutes instead of every minute or so).
Here is the path to my github:
BTW, if you have any connectivity issues with the Keen Vents, try to
-
Press the black button at the side of the Keen Vents to do a reset. You may need to re-connect
the faulty vent to the ST hub -
If still not working, you may try to remove the batteries and put them back to re-initiate the connection with the ST hub. You may need to try several times till the green led flashes.
-
If it’s still not working, you may want to contact Nate and exchange the faulty vent. They have a 2-year warranty
so it should not be a problem.
I had to exchange one myself because of some faulty sensors on it. The reported temp by the sensor was…250 degrees Celsius…Which is also quite a lot of Farenheits…
Regards.
@yvesracine, (fyi: @ashutosh1982, @Mike_Maxwell,@GreggKeenHome)
Thanks for working with their engineers and figuring out the polling changes. I just bought one for myself and tweaked your device type for myself for look and feel in the app:
https://raw.githubusercontent.com/constjs/SmartThings-Devices/master/keen_home_vent.device.groovy (sorry for not forking yours btw)
- Used multiAttributeTile w/slider control
- Converted pressure from pascal to inches of mercury (Hg) even though it serves no purpose for anything yet
except to fill in a tile… - Used the “st.vents.vent-open” icon since it used no words and it was better centered in the tile than ST’s default. I added “label” for open, close, and the other 2 states
I remember at one time ST published all their icons at http://scripts.3dgo.net/smartthings/icons/, including these vent icons. There’s one for closed without the arrows, but I have no idea what it is anymore, and I literally guessed for the one I used. Does anyone know where I can find all those other icons ST uses???
Besides wishing pressure was the actual pressure at the vent, I wish I knew why the slider value never stays at 100% (where I left it). As soon as I go back into the device, it’s back to 95%, or sometimes a little lower. If you know why, can you let me know?
I got my vent from Lowes, and it paired up just perfectly the first time. Now time to start integrating it, and getting more of them!
@johnconstantelo, the setting reverts to the max that’s reported by the device after you change it.
Internally it’s a simple pot on the end of the actuator shaft, its annoying as the analog value could have easily been translated and offset to 0 and 100 during the auto init routine the thing does when you replace the batteries.
Right on time, man! I was planing a trip to Lowes tomorrow to get 5 if they have them in stock. Been playing for a while with my dumb vents to see if I can adjust the temps in our bedrooms and so far so good. Having the ability to open/close them remotely is all I need right now.
@johnconstantelo,@Mike_Maxwell, @ashutosh1982, @yvesracine …have you guys been able to use the actual temp sensor on these vents, or using external sensors?
Cool! Don’t forget to order them online to grab a discount and then pick them up at the customer service desk the same day. That’s what I did.
http://renovopower.com/lowes.html
I literally ordered it online before I left work and selected Store Pickup and applied my promo code. I picked it up 10 minutes later.
External sensors. The temp at the vent is only usable to know that you’re blowing cold/hot air (hvac is working as expected maybe), but using it for any decision making to shut vents down is useless.
Thanks, that’s what I remember Mike saying, but was hoping that someone found a way to use them…
Hi, my smartapps use the vent temp sensor to check if the temp inside the vent is not too hot or too cold indicating that there are too many vents closed within a zone.
That’s it, I use an external temp sensor to get the actual room temperature as the vent temp sensor is affected by the airflow.
Regards.
Yup, for sure they can tell you the furnace is running…
Is there not a pressure sensor on the vent? I thought they measured backflow pressure to verify they weren’t closing to many vents…