Announcement

Collapse
No announcement yet.

Predict icing conditions on cars

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Predict icing conditions on cars

    Hi all,

    I am going to spend the Holidays trying to solidify my WAF. Things are going really good now. [img]/infopop/emoticons/icon_cool.gif[/img] Earlier this week I asked the wife "what is the coolest thing you want me to do with this HA stuff?"

    To my surprise her answer was "Get Leon (our HS machine is Leon) to let me know if there is ice on my car in the morning, so I can go out early enough to clean it off".

    Well, there you go. I have been thinking about how to accomplish this. I have ruled out things such as automatic car starters, 12v heaters, etc., and want to address the problem with HS. I already have good interface to VWS and Temp05 so I'm hoping I can do it with some calculation using temperature, dew point, etc. I'm having trouble finding a calculation to use for a starting point. For example earlier this week, the minimum outside temperature was 39.50 degrees, and there was ice on the car...

    Ive also thought about installing an ibutton temperature sensor on the windshield, and using a wireless ibutton transmitter...Has anyone ever tried this?

    Any comments are appreciated. I figure I can spend a couple of hundred as an investment in WAF.

    Cheers
    Tom

    #2
    Weather Display has a built in email warning for frost prediction. Its nice. I know as soon as I get up if there is frost and use my automatic car starter to warm up the car. Now if I can figure out a way to hack the remote to do it automatically. That would be cool.

    -Rupp
    ...it was a holy night.
    -Rupp
    sigpic

    Comment


      #3
      <BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Rupp:
      Weather Display has a built in email warning for frost prediction. Its nice. I know as soon as I get up if there is frost and use my automatic car starter to warm up the car. Now if I can figure out a way to hack the remote to do it automatically. That would be cool.

      -Rupp
      ...it was a holy night.<HR></BLOCKQUOTE>

      You can do this. Open up your auto car starter remote, find the two connections that engage the auto starter. Connect these to a Powerflash unit. Control Powerflash unit via HS.

      A buncha computers, a buncha HA stuff, and 10 cats. All managed with a grapefruit sized brain!
      Hmmmm......

      Comment


        #4
        Since you have a weather system attached to HS, it should not be too difficult to know when conditions are such that ice COULD form on your car. Basically, temp at or below freezing and a source of moisture. The moisture could be precipitation or condensation if the temp is below the dew point (does your VWS give you dew point?)

        If you had ice on your car but your system showed the low temp to be 39.5 degrees, you might want to check the calibration of your temp sensor. I don't believe ice could form at that temp. Of course, the temp sensor may be accurate but located in a place where it's not accurately measuring the temp where you car is located.

        Comment


          #5
          I could but thats $85 for a new remote (to carry with me) and $20 for a power flash. I want something that will send the RF signal. Are there any RF learning remotes that are cheap?

          -Rupp
          ...it was a holy night.
          -Rupp
          sigpic

          Comment


            #6
            Don't forget the wind factor. Weather Display uses "alarm will occur if hour is past 9pm and before 9AM, and the current dew point is less then 3°C, and the current temp is 6°C or less, and the temp has dropped by at least 1°C in the last hour, and the average wind speed is 3 knts or less for the last hour) So its not a trival calculation.

            -Rupp
            ...it was a holy night.
            -Rupp
            sigpic

            Comment


              #7
              Granted, there is more to it than I stated. It sounds like that system you are using is trying to predict when it's LIKELY for ice to form. That would be even better for T1's needs if he has the setup to allow it.

              Actually, I might fudge a little if I were setting it up. I might use 34 or 35 degrees and temp within 2 or 3 degrees of dew point. That would compensate for some inaccuracy in the sensors, placement, etc.

              Comment


                #8
                Rupp
                I agree, the calculation is complex. Clearly (I mean if the sky is clear) it is possible to form ice or frost if the ambient temperature is above 32f. I found the post below on the Weather Monitor board. I'd really like to find a calculation or experimental data point for a starter.
                Tom
                *******from the Weather Monitor Message Board***
                Frost prediction
                The Bureau of Meteorology considers a number of factors when estimating the
                probability of a frost. These factors include:
                General weather situation
                Particularly favourable for frost development is the end of a depression, which is
                associated with a clearing of cloudy and possibly rainy conditions during the day to
                give a clear, still night.
                Wind
                Conditions of no wind are most favourable for radiation frost development.
                Cloud
                A cloudy day followed by a cloudless night produces the greatest frost risk. The
                cloudy day reduces the sun’s ability to heat the soil surface and when followed by a
                clear night what little heat is stored quickly dissipates. However, only a small amount
                of cloud at night is required to prevent a frost from developing.
                Dew point
                The dew point is the air temperature at which dew or condensation begins to form.
                Low dew point indicates dry air, which means that very little heat is released as the air
                cools and as moisture, condenses. This in turn leads to a rapid fall in temperature
                and a greater likelihood of frost.
                Experience has been that if the dew point in the evening exceeds about 5.5°C then
                there will be sufficient radiation reflected back by the atmosphere (of heat lost from
                the ground surface) to retard the rate of cooling and limit the probability of a frost. A
                dew point of less than 2.2°C indicates a high probability of frost.


                Good Luck

                Cyclone

                Comment


                  #9
                  DC
                  Sorry,I was composing whilst you were posting.

                  What I am planning now (unless I can find some experimental data) is writing some rules regarding dew point, temperature and cloud conditions and tweek as necessary. The better the calculation, the better the WAF...

                  Rupp
                  Do you have access to the formula the Weather Monitor uses?

                  Tom

                  Comment


                    #10
                    'Round here, if it's cold there's ice.

                    Why wouldn't it be as simple as checking the temp? Plus, if it's 33 degrees out, I don't know about the rest of you, but I would say that a cold temp is cold enough to start the car and warm it up, ice or not. [img]/infopop/emoticons/icon_smile.gif[/img]

                    Dan-O
                    Dan-O
                    HomeSeer contributor since summer 1999, yes 1999!

                    Comment


                      #11
                      How about using a.... &lt;drumroll&gt; ... Frost Detector! Or maybe a... Frost Sensor! Or perhaps a Frost Indicator? [img]/infopop/emoticons/icon_rolleyes.gif[/img]

                      -Nitrox

                      Comment


                        #12
                        I think the WAF would go out of the roof if she had a warm car each morning whether it frosted or not.

                        http://shop.store.yahoo.com/advantag...to-ps2805.html

                        -Rupp
                        ...it was a holy night.
                        -Rupp
                        sigpic

                        Comment


                          #13
                          Yes a warm car each morning- a garage.

                          I like the idea of homeseer starting the car each morning- it is good to let the thing idle for a minute or so anyways.
                          HS3 Pro Edition 3.0.0.435 (Windows Server 8.1 on ESXi box)

                          Plug-Ins Enabled:
                          Z-Wave:,RaspberryIO:,AirplaySpeak:,Ecobee:,
                          weatherXML:,JowiHue:,APCUPSD:,PHLocation:,Chromecast:,EasyTr igger:

                          Comment


                            #14
                            Yep, The WAF has been an uphill struggle ever since I took out the garage door, installed a wall, an air-conditioner, and turned the garage into a shop.

                            I've taken Rupp's advice, and ordered a remote starter.

                            I've got the icing prediction calculation under construction (see post in script development forum), and hope to get the shopping list script running this weekend.!

                            Thanks
                            Tom

                            Comment


                              #15
                              You could always download a trial version of Weather Display and run it in the METAR station-less mode. This way you could get all kinds of weather warnings as well as frost prediction.

                              -Rupp
                              ...it was a holy night.
                              -Rupp
                              sigpic

                              Comment

                              Working...
                              X