Vera - Smarter Home Control Forum

General => Temperature Monitoring & HVAC Control => Topic started by: mclauli3 on March 20, 2011, 06:04:11 pm

Title: Temperature control using Ver2
Post by: mclauli3 on March 20, 2011, 06:04:11 pm
I would like to use Vera2 to control temperature in a number of rooms. As this is Ireland it is a heating application :).

I would fit a temperature sensor in a room and have vera open and close a heating valve based on the temperature. Is it possible to do this with a scene(s) and if so how?

Thanks, Liam
Title: Re: Temperature control using Vera 2
Post by: mclauli3 on April 03, 2011, 09:39:41 am
Do I need to learn luup or can this be done with a scene?

Has anyone tried to control temperature in this or a similar way. It would eliminate the need for a thermostat to do the controlling?

Thanks, Liam
Title: Re: Temperature control using Ver2
Post by: huogas on April 03, 2011, 12:10:00 pm
Quite easy to set up a scene that will trigger an actuator for opening or closing a valve, but not sure it will make the job. If doable, maybe not recommendable...

Just think about the strategy to really control the temperature. At what temperature do you close the valve in order the stay on the target ? Today's thermostats have proportional control to keep the temperature on the setup point.

Also I doesn't even want to think at what would happen if Vera fails...

Doable, but a thermostat is definitely recommandable... ;)

By the way, it could be all done with scenes, without programming.
Title: Re: Temperature control using Ver2
Post by: mclauli3 on April 03, 2011, 05:31:09 pm

Thanks huogas.

Sounds about right.

Are there thermostats available that can accept a remote z-wave temperature setpoint?
Title: Re: Temperature control using Ver2
Post by: huogas on April 03, 2011, 06:50:35 pm
Yes. All Z-Wave thermostats do that. Please check on your favorite online store.

There is not too many choices. They are all low voltage devices. It should make the job for your situation.

Ask about specifics.
Title: Re: Temperature control using Ver2
Post by: oTi@ on April 03, 2011, 10:25:48 pm
Are there thermostats available that can accept a remote z-wave temperature setpoint?
And there are Z-Wave radiator thermostats as well, I believe; if that's what you meant. Check Danfoss.
Title: Re: Temperature control using Ver2
Post by: FlyBoyBob on April 04, 2011, 08:37:48 am
Liam,

I am doing exactly what you describe. Here is an overview and I can post details if you are interested:

I have a z-wave (Trane) thermostat as my master thermostat - with daily schedules programmed.

In 3 separate rooms I have either a temp/humidity sensor or a 3-in-1 with temperature, all z-wave

I have 24v normally-open Honeywell zone valves controlling the cast-iron radiators in each room I want to control, with a dry-contact z wave switch controlling the 24v to the valve.

In the Vera I read the current temperature from the main thermostat, then the temperature in the room I want to control, and if the room is higher I close the valve. Yes there is a tiny bit of Luup code involved but it is as simple as it gets.

I also control the radiator nearest the main thermostat to balance the system.

Note that if the Vera or any device were to fail I would simple get rooms that are warmer than I want.

This can also be done as a proper zone-controlled system by using zone valves that are normally closed and have "end contacts" to trigger your heating system.

More details on any of the above if you want...
Hope this helps,
bob
Title: Re: Temperature control using Ver2
Post by: markbannister on April 04, 2011, 09:44:53 am
OT -- what temp/humidity sensors are you using?
Title: Re: Temperature control using Ver2
Post by: FlyBoyBob on April 04, 2011, 09:54:51 am
HM-TS001 - Z-Wave Temperature / Humidity Sensor

http://smarthome-products.com/p-1435-hm-ts001-z-wave-temperature-humidity-sensor.aspx

These devices are often out-of-stock most places but Jay at Smarthome-products.com seems to be able to get them, and at discounted prices...

Hope this helps,
bob
Title: Re: Temperature control using Ver2
Post by: huogas on April 04, 2011, 12:33:59 pm
@Bob

What do you achieve as control ? I mean what is the span around the set point ?

(as an example, if the set point is 20C, what are the lowest and the highest temperatures observed ?)
Title: Re: Temperature control using Ver2
Post by: FlyBoyBob on April 04, 2011, 12:54:13 pm
What do you achieve as control ? I mean what is the span around the set point ?

(as an example, if the set point is 20C, what are the lowest and the highest temperatures observed ?)

That all of course depends on your heat delivery system, heat loss in the room, and air infiltration. I have an old Amish Farmhouse built and re-built over several hundred years, currently with a hot water system with cast-iron radiators and some in-floor radiant heating that I am adding.

My reason for controlling the temperatures in individual rooms is due to the variables above - on cold windy days sometimes it's not enough heat, on sunny calm days it's way too much without individual sensors and controls.

The point is, regardless of the variables, if it's too hot in a given room compared to the main thermostat setpoint I (or the Vera I should say) simply stop the hot water going to that radiator. If the temperature at the main thermostat is higher I turn off the radiator in it's room. And turn the radiators back on if it's colder.

I am going to use > +/- 1 degree in my LUUP code right now but am still experimenting. Scenes can vary that = for instance I will be setting my bedroom warmer than the setpoint for the rest of the house at night. I might even take outside temperature, sunlight, and humidity into account: the possibilities are endless for a tinkerer like me!  ;D

bob
Title: Re: Temperature control using Ver2
Post by: huogas on April 04, 2011, 01:29:14 pm
Thanks Bob for the explanations.
Title: Re: Temperature control using Ver2
Post by: mclauli3 on April 05, 2011, 03:42:06 pm
Hi Bob,

Thanks for the information. It is very useful. The background to my installation is as follows:

I am building a new house in Ireland with a very high specification for insulation and air tightness (more or less Passiv standard). This will need very little heat and no cooling. The only heating I am putting in is underfloor heating operating at 40C (104F) water temperature (from a high efficiency low temperature air source heat pump) in 3 rooms (2 beds and a bethroom). The house will have a mechanical heat recovery ventilation system which will keep the whole house at the same temperature (I hope!)

The heat pump has a 3 port valve to turn on/off the underfloor heating. I have provision for, but am not yet fitting actuators to the three rooms, i.e. they will all act together and will initially be always open. I am looking to have a z wave solution to control the 3 port valve (on/off) with a smallish deadband.

I was considering putting Vera to control the temperature but based on feedback here I am now considering a z wave thermostat (like you suggest) to control the 3 port valve based on the temperature in a different room (I am hoping that all rooms are the same temperature and the heat finds its way via the HRV to all rooms) to the 3 rooms with underfloor heating. The thermostat would have timers/setpoints I assume. Is there an advantage to having Vera involved as well? Regards, Liam



Title: Re: Temperature control using Ver2
Post by: computerjohn on April 05, 2011, 03:53:36 pm
Good find my friend!!

HM-TS001 - Z-Wave Temperature / Humidity Sensor

http://smarthome-products.com/p-1435-hm-ts001-z-wave-temperature-humidity-sensor.aspx

These devices are often out-of-stock most places but Jay at Smarthome-products.com seems to be able to get them, and at discounted prices...

Hope this helps,
bob
Title: Re: Temperature control using Ver2
Post by: FlyBoyBob on April 05, 2011, 03:56:58 pm
Good find my friend!!

http://smarthome-products.com/p-1435-hm-ts001-z-wave-temperature-humidity-sensor.aspx

Get to know Jay at smarthome-products.com - not only does he sell all the good stuff but he has two houses kitted out to the max with zwave toys, and he knows what he's talking about!

In my experience - if you want something you can't find he'll find it for you, or tell you it can't be done.
Title: Re: Temperature control using Ver2
Post by: FlyBoyBob on April 05, 2011, 04:06:10 pm
Liam,

Here's an important point about your house - does your heat recovery ventilation system circulate air throughout all of the rooms? If it does then the only thing that zone control will do for you is give you cold floors in some rooms and hot in others.

As I said my old house has cast-iron radiators and now some in-floor radiant, but no air circulation between rooms. I can have my bedroom be several degrees warmer than the rest of the house at night even with the door open - you can't do that with air circulation.

Conversely on a sunny day with the in-floor and a radiator going in my bathroom it has gotten up to 78F while the main thermostat is regulating to 68F, while on a cold windy winter's day (bathroom is on the weather side of the house) it is COLD in there.

Now with a 3-in-1 and a zone valve on the big old radiator I have the 3 bears solutions = not too cold, not too hot, just right! Independent of the weather outside.

bob
Title: Re: Temperature control using Ver2
Post by: mikeholczer on May 30, 2011, 07:15:56 pm
I've been trying to do so something similar and have a HomeManageables TS001, but I have not been able to get it to update regularly enough to act as a trigger for scenes. Has anyone been able to get the TS001 to wakeup more often at then the factory setting? I set the wakeup internal to 60 (I think seconds) and the polling to 60 as well. I know this is probably too aggressive, for battery performance, but I was try to test out my scenes without having to wait too long. The device did not checkin every minute like I had expected. Anyway, any help on configuring the TS001 to wakeup and be pollable would be great.

CORRECTION: It does seem to be waking up every minute (judging by the "LastWakeup" variable), but it doesn't seem to be staying pollable. Vera doesn't get temp changes within a minute of them happening and the disable often showes "Cannot send command to node" when attempting to manually poll.
Title: Re: Temperature control using Ver2
Post by: pgrover516 on June 02, 2011, 11:20:22 pm
I have three of the TS001's though 5 min is about as short as I've ever set the wakeup they seem to report fine at that frequency (though I have had one or another misbehave at random and require exclude, factory reset, re-include to correct) in testing I could never see any benefit to polling any of my battery powered sensors, and indeed high polling frequencies acctually degraded Veras performance (presumably by keeping her too busy) I now keep polling to a minimum for wired sensors and 0 for battery sensors and have gotten my most reliable performace this way