Page 3 of 16 FirstFirst 1234567813 ... LastLast
Results 21 to 30 of 152

Thread: Measuring real time gas consumption

  1. #21
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,850

    Default

    Quote Originally Posted by paulockenden View Post
    I think to a degree it also depends on the home. The thermal mass, the insulation, etc.

    There's also a comfort element. After an 'off' period a room can be technically up to temp (i.e. air temp is OK), but the floor, furniture, etc. can still feel cold.
    I think this is largely only the case when measuring the temperature at the HR92 beside the radiator.

    We had the same issue in our living room where on a cold morning it would get up to the reported 21 degrees after about 1 1/2 hours but the room still felt a lot colder than it did later in the day, even though the reading stayed regulated at 21 degrees. A couple of hours later "21" now felt fine.

    I then left a standalone thermometer on the coffee table in front of the sofa and compared that to the HR92 during warm up and found the real cause - during initial heat up when the HR92 first reported it had reached 21 the room temperature away from the radiators was still in fact only 18 degrees. And yes, that was air temperature that was 18, not furniture or floor temperature. (The floor is carpeted anyway) Over the following 2 hours or so the coffee table reading would gradually creep up from 18 to 21 and stabilise while the HR92 reading stayed the same, and by then the room would be comfortable.

    I've talked at length in a couple of other threads why this is the case and I'm sure you've probably read it so I won't repeat here.

    I changed to a wall mounted DTS92 and tried three different locations in the room for the sensor before finding that beside the light switch near the door behind the sofa gave the best correlation between comfort and temperature reading.

    Now the room is still scheduled to 21 degrees but the DTS92 and coffee table thermometer (since removed) agree with each other within about half a degree even during the warm up phase, and more importantly when the room is first reported to have warmed up to 21 degrees it now actually does feel comfortable. Optimal start comes on about an hour earlier than before but this is correct because the room was never really up to temperature in the time that it thought it was based on the HR92 radiator side reading.

    It's amazing how different the response was with the DTS92 in three different locations in the room, so it is worthwhile trying a remote sensor in more than one location to find one where a given numerical value gives the most consistent feeling of comfort under varying external conditions.
    Last edited by DBMandrake; 31st October 2016 at 11:49 AM.

  2. #22
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,850

    Default

    Quote Originally Posted by jdp80 View Post
    There's a Python API - https://github.com/pavoni/pyloopenergy

    I wouldn't be using it for billing purposes, but as a rough and ready elec (10s) + gas (15min) value, it works well
    So you're using this successfully ?

    I'm tempted by loop, and as well as their web and iPhone app based reporting which looks pretty good, the python API would allow me to write a munin and/or domoticz plugin to graph along side my current evohome zone temperature graphs, which I like the idea of very much...

    Edit: Just noticed that loop uses 868Mhz to communicate back the the receiver. Whoops....

    Has anyone had any problems with Loop interfering with Evohome communications ? I already have an intermittent issue with my hot water temperature sensor not reporting in regularly that I am troubleshooting, I don't want to make matters worse and add unknown variables by adding more 868Mhz devices in the house unless I know for sure they won't cause an issue.
    Last edited by DBMandrake; 2nd November 2016 at 05:06 PM.

  3. #23
    Automated Home Sr Member
    Join Date
    Sep 2015
    Posts
    59

    Default

    Quote Originally Posted by DBMandrake View Post
    So you're using this successfully ?

    I'm tempted by loop, and as well as their web and iPhone app based reporting which looks pretty good, the python API would allow me to write a munin and/or domoticz plugin to graph along side my current evohome zone temperature graphs, which I like the idea of very much...

    Edit: Just noticed that loop uses 868Mhz to communicate back the the receiver. Whoops....

    Has anyone had any problems with Loop interfering with Evohome communications ? I already have an intermittent issue with my hot water temperature sensor not reporting in regularly that I am troubleshooting, I don't want to make matters worse and add unknown variables by adding more 868Mhz devices in the house unless I know for sure they won't cause an issue.
    I sometimes lose readings from the gas sensor, but that is pretty much always due to the sticky pad holding the sensor to the meter failing after 18 months of being attached.

    The Loop devices are outside the house, about 12 meters in distance from the loop receiver. Between that distance is my Evohome controller (pretty much direct line of sight if there wasn't any walls in the way). I've had no reception issues or loss of comms reported on either devices.

  4. #24
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,850

    Default

    Ok.

    My concern is my gas meter is immediately above my boiler inside the boiler closet, and also in the closet I have only about 600mm away from where the loop sensor would be, 3x BDR91 and a CS92.

  5. #25
    Automated Home Jr Member
    Join Date
    Mar 2016
    Posts
    37

    Default

    Quote Originally Posted by DBMandrake View Post
    So you're using this successfully ?

    I'm tempted by loop, and as well as their web and iPhone app based reporting which looks pretty good, the python API would allow me to write a munin and/or domoticz plugin to graph along side my current evohome zone temperature graphs, which I like the idea of very much...

    Edit: Just noticed that loop uses 868Mhz to communicate back the the receiver. Whoops....

    Has anyone had any problems with Loop interfering with Evohome communications ? I already have an intermittent issue with my hot water temperature sensor not reporting in regularly that I am troubleshooting, I don't want to make matters worse and add unknown variables by adding more 868Mhz devices in the house unless I know for sure they won't cause an issue.
    Yes, works well - I'm running a Python script to submit the data into Domoticz.
    chart.jpg
    chart.jpg

    I haven't noticed any interference with my Evohome setup.

    Technically Loop is quite good, but it doesn't generate proper billing figures, and I am suspicious of the tariff recommendations.

  6. #26
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,850

    Default

    Quote Originally Posted by jdp80 View Post
    Yes, works well - I'm running a Python script to submit the data into Domoticz.
    chart.jpg
    chart.jpg
    Perfect.
    I haven't noticed any interference with my Evohome setup.
    That's good to know - however do you have an S/Y Plan system with the hot water kit ? And if so how far is your gas meter and Loop sensor from your CS92 ?
    Technically Loop is quite good, but it doesn't generate proper billing figures, and I am suspicious of the tariff recommendations.
    I wouldn't be using the Tariff recommendations anyway - I can figure that out for myself. I want to see the raw data numerically and graphed.

    When you say the billing figures are wrong, do you enter in your current tariff and it counts the kWh and cubic feet of gas, and is supposed to calculate from that which should in theory match your bill ?

    Does it take into account and let you specify standing charges as well as the unit rate ?
    Last edited by DBMandrake; 3rd November 2016 at 03:40 PM.

  7. #27
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,850

    Default

    Well I've ordered loop, which should be here in a few days, so we'll see if it lives up to its claims or not!

    A quick question regarding the gas meter attachment - it uses an optical sensor but its not clear whether it is expecting to look at the least significant digit turning or the clock dial ?

    Our gas meter is a mechanical one that has 4 white digits, two red digits and a clock dial with a red pointer - both the clock dial and the least significant (right most) red digit appear to be 1 cubic foot. So does the sensor attach over the right most red digit, or does it attach over the top of the clock face so that it catches the red dial as it goes by ?

    If the optical sensor is just a simple brightness sensor would it be fooled every time I open the cupboard door to the boiler causing it to read a false cubic foot of gas or is it a bit smarter than that, eg is it actually an image sensor not just a light sensor ?
    Last edited by DBMandrake; 9th November 2016 at 02:20 PM.

  8. #28
    Automated Home Sr Member
    Join Date
    Mar 2016
    Posts
    52

    Default

    Quote Originally Posted by DBMandrake View Post
    Well I've ordered loop, which should be here in a few days, so we'll see if it lives up to its claims or not!

    A quick question regarding the gas meter attachment - it uses an optical sensor but its not clear whether it is expecting to look at the least significant digit turning or the clock dial ?

    Our gas meter is a mechanical one that has 4 white digits, two red digits and a clock dial with a red pointer - both the clock dial and the least significant (right most) red digit appear to be 1 cubic foot. So does the sensor attach over the right most red digit, or does it attach over the top of the clock face so that it catches the red dial as it goes by ?

    If the optical sensor is just a simple brightness sensor would it be fooled every time I open the cupboard door to the boiler causing it to read a false cubic foot of gas or is it a bit smarter than that, eg is it actually an image sensor not just a light sensor ?
    there are fitting instructions for each of the meter types in the pack, an uber-diyer such as yourself should have no issues . suspect I have same meter as you, 1970s job. It sticks (they provide mounting tape) right on to the glass face of the dial, so should be immune to your cupboard problem, and it watches the dial. I just recalibrated mine after a year of running (i.e. I checked what loop thought the gas meter reading should be, versus what it actually is) and it was only out by 20 units or so. happy with that.

    the electric one is less accurate, due to inductive coupling it over-reads when the usage is low (I have tried to calibrate, but gave up, too damn hard).

    as others say, when it comes to switching your provider, take their monetary and tariff stuff on their site with a pinch of salt.
    take your own meter readings periodically to check the accuracy, dump their data into your choice of format and do your own thing via all the comparison sites.

  9. #29
    Automated Home Legend
    Join Date
    Jul 2014
    Posts
    1,003

    Default

    Had they not forced gas and electric as a single package I would have bought the loop too. I have a self built electric that does solar diversion and electric readings, and I've finely calibrated this to within 1KWh, which is probably as good as its going to get.
    I now plan to build my own gas monitor but will be looking at the turning needle instead of the digits to work out when a unit has ticked over.

  10. #30
    Automated Home Sr Member
    Join Date
    Sep 2015
    Posts
    59

    Default

    Quote Originally Posted by DBMandrake View Post
    Well I've ordered loop, which should be here in a few days, so we'll see if it lives up to its claims or not!

    A quick question regarding the gas meter attachment - it uses an optical sensor but its not clear whether it is expecting to look at the least significant digit turning or the clock dial ?

    Our gas meter is a mechanical one that has 4 white digits, two red digits and a clock dial with a red pointer - both the clock dial and the least significant (right most) red digit appear to be 1 cubic foot. So does the sensor attach over the right most red digit, or does it attach over the top of the clock face so that it catches the red dial as it goes by ?

    If the optical sensor is just a simple brightness sensor would it be fooled every time I open the cupboard door to the boiler causing it to read a false cubic foot of gas or is it a bit smarter than that, eg is it actually an image sensor not just a light sensor ?
    So the optical sensor attaches and monitors the last red digit. Calibration requires you to have your heating on for 30 minutes initially once it's all attached & registered. From that point on, I've found it to be fairly accurate in monitoring usage, and only need to adjust the meter reading value on Loop by about 5 each month. The optical sensor monitors the reflectivity of the numbers, so opening the box shouldn't have any impact on the accuracy of readings (we sometimes get couriers leaving parcels in the meter box and had no issues other than the sensor coming unclipped due to the just throwing the parcel at the meter)

    It will come with an array of clips and fitments to suit a variety of meters, but the instructions for installing it are somewhat vague (or atleast they were when I fitted it 18mo ago).

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •