Room Temperature Sensing

[mattpg...@gmail.com]

Hi Team,

Apologies if this has been asked and resolved 1000 times.

I'm finding my 1 wire temperature sensors to be quite inaccurate.

They are installed behind my retractive light switches in each room.

Is there maybe something affordable that I can put on the loxone air that can be more reflective of the room temperature?

Cheers

Matt

Sent from Yahoo Mail on Android

[Toby Mills]

if there are multiple in a room, I combine them all together and average them and then put that average behind a moving average block.

[George Campbell]

Hi,

What kind of sensors are you using? Are the GENUINE sensors?

I have found the cheap ones from ebay to be quite innaccurate, when compared to the genuine DS18B20 sensors from CPC. 

George

[Duncan]

i found that it wasnt the 1-wire sensors themselve (chinese or otherwise) causing innacurate readings, but the position behind the switch facings - a combination of heat transfer delay, cooler on outside walls and sometimes drafts all combined to make these incorrect most of the time

it may be that you need another solution and there are many - i swapped some of my switches to knx mdt glass with inbuild sensors and used shelly h&t in a couple of locations and calibrated them against a professional 0.1degC accurate thermometer

[Paulo Matos]

Duncan <joanne...@gmail.com> writes:

> i found that it wasnt the 1-wire sensors themselve (chinese or otherwise)
> causing innacurate readings, but the position behind the switch facings - a
> combination of heat transfer delay, cooler on outside walls and sometimes
> drafts all combined to make these incorrect most of the time
>
> it may be that you need another solution and there are many - i swapped
> some of my switches to knx mdt glass with inbuild sensors and used shelly
> h&t in a couple of locations and calibrated them against a professional
> 0.1degC accurate thermometer
>
>

I am also quite disappointed with having all these temperature and
humidity sensors installed behind my switches. I have one per room, in
absolutely bonkers location which was installed when the house was
built. However, the readings are anything but accurate.

I am thinking about getting a device that is open and I can read by
loxone. Netatmo seems quite expesinve but I am looking for
alternatives. I don't care if they are visible as long at the design is
not horrible, they are accurate, and I can get the sensor information
somehow into loxone. Any suggestions?

Paulo Matos

>
> On Saturday, 6 August 2022 at 20:04:41 UTC+1 g...@camleyphotographic.com
> wrote:
>
>> Hi,
>>
>> What kind of sensors are you using? Are the GENUINE sensors?
>>
>> I have found the cheap ones from ebay to be quite innaccurate, when
>> compared to the genuine DS18B20 sensors from CPC.
>>
>> George
>>
>> On Saturday, July 30, 2022 at 6:02:11 AM UTC+1 mil...@np.co.nz wrote:
>>
>>> if there are multiple in a room, I combine them all together and average
>>> them and then put that average behind a moving average block.
>>>
>>> On Tuesday, 19 July 2022 at 18:47:12 UTC+12 mattpg...@gmail.com wrote:
>>>
>>>> Hi Team,
>>>>
>>>> Apologies if this has been asked and resolved 1000 times.
>>>>
>>>> I'm finding my 1 wire temperature sensors to be quite inaccurate.
>>>>
>>>> They are installed behind my retractive light switches in each room.
>>>>
>>>> Is there maybe something affordable that I can put on the loxone air
>>>> that can be more reflective of the room temperature?
>>>>
>>>> Cheers
>>>>
>>>> Matt
>>>>
>>>> Sent from Yahoo Mail on Android

>>>> <https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub2=Global_YGrowth&af_sub3=EmailSignature>
>>>>
>>>


--
Paulo Matos

[Duncan]

i would recommend the new Shelly h&t 2

it can send the data using udp straight to the miniserver, has an e-ink display and can be battery or usb powered

you can also adjust the calibration internally if required

[Paulo Matos]

Duncan <joanne...@gmail.com> writes:

> i would recommend the new Shelly h&t 2
>

I cannot find an H&T 2. I assume you mean the H&T plus?

https://shop.shelly.cloud/shelly-plus-h-t-wifi-smart-home-automation

--
Paulo Matos

[Duncan]

sorry yes its version 2 (in my mind) but they call it the plus - im going to replace my original h&ts with these plus models as they look better on a wall or furniture and are more 'usual' looking, plus a much longer battery life with the new batteries

[Rob_in]

On Tuesday, 19 July 2022 at 08:47:12 UTC+2 mattpg...@gmail.com wrote:

They are installed behind my retractive light switches in each room.

As others have noted, that's probably the problem.

Funnily enough I have recently decided to consolidate our control/sensor buses and just removed a 1-Wire Extension. That will be listed for sale shortly if anyone is interested :D

This is absolutely nothing to do with accuracy or reliability of the sensors or bus, but because I wanted more readings (mainly air quality) and 1-Wire can't handle that easily (I did experiment with some DIY modules that presented AQ readings on the 1-Wire bus but didn't like that solution).

Anyhow, while doing this I have noticed:

1. The 1-Wire sensors I removed are actually pretty damn good. I have Unica temperature/humidity/light versions and they have been flawless the last few years. If positioned properly you should have no issues.

2. 1-Wire sensors can be installed with zero supporting circuity, so as they do not have any electronics 'self heating' from said nearby electronics cannot occur. If you have your sensors behind electronic wall switches or even in the same box as such stuff this is likely going to stuff up sensor readings.

3. Even putting a sensor inside a wall mounted box (the vented type built for thermostats) can cause them to read differently than having the sensor float on a wire poking 10-15cm out of the wall and floating in space. Don't ask my why, maybe our walls have thermal mass? Maybe there is better airflow away from the wall? Either way, it's such a shame a sensor floating in mid-air is ugly because it certainly seems to be the most accurate place for them ;)

Anyhow, hope that's useful to someone.

Robin

[Duncan]

there is a way to make the 1-wire sensors behind light switches more accurate, but it requires changing switches

i used Schneider screwless flat plate grid switches and you can buy a flat metallic blank for unused switch spaces

in each room i used a switch with an extra space and put a flat metallic blank in

i connected the 1-wire sensor to a 10cm 3core cable with miniature plug/socket (jst type)

i glued the 1-wire sensor to the back of the metallic blank using thermal conductive glue (used for heatsinks) 

then insulated the back of the plate/sensor with a blob of squirty foam insulation

now you have a relatively large heat conductive metal plate between the room air and the sensor and its reasonably quick response time, the only issue being that as its close to the door in the light switch, its subject to inaccuracy when a warm room has the door open to a colder hallway, but this is true of any mechanism that uses this sensor location

a sensor further into a room away from doors and windows makes far more sense, hence my recommendation to use something like the shelly h&t (plus, not 2!) which can be placed in a more suitable location such as on furniture or wall mounted away from the door