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Discuss Weather compensation sensors in the Central Heating Forum area at

  1. doitmyself

    doitmyself Well-Known Member

    Never heard of 100 ohms. 5k, 10k, and 12k (ohms), yes.

    Boiler makers tend to keep this info to themselves - so you have to buy their product at inflated prices?

    I agree that installers need to understand the benefits of modern controls. (I asked one well-established installer what he thought of weather compensation. He thought I was taking about frost protection.)
  2. YorkshireDave

    YorkshireDave Plumber Top Contributor!!

    Didn't think I was that bad... You made me check :rolleyes:
    Farnell's (where I buy most of my electronic components) have 'em in the range 47 ohms to 100k including 100 ohms.

    Old but not quite written off yet...:cool:

    I am intrigued. What do YOU understand by weather compensation?
  3. doitmyself

    doitmyself Well-Known Member

    Yes, NTC thermistors are available in a wide range of values and tolerances. As you say, the temperature/resistance curve is not exactly linear. I did read that it is possible to make it linear, but can't remember how. May be the boiler mfr does this within the PCB.

    As far as I am concerned, weather compensation is a method of varying the flow temperature in inverse proportion to the outside temperature; i. e the colder it gets, the higher the temperature. The reason for doing this is that the heat required to maintain a certain temperature in the house is directly proportional to the difference between inside and outside temperatures, so radiator output needs to vary. As the output of radiator varies with water temperature, it is logical to use this fact to obtain the required output.

    Incidentally, TRVs work much better if weather comp is used.
  4. YorkshireDave

    YorkshireDave Plumber Top Contributor!!

    Yaa. Someone clued up... :D

    A vital element of compensation is the rate of heat loss. This differs from building to building and is also directly impacted by weather. Specifically wind (strength and direction) and local temp. The true rate of loss can only be measured via embedded sensors i. e. embedded in the building fabric.

    Unfortunately, today we assume weather based on internet data and have removed embedded sensors. This leaves, at best, vauge approximations of conditions and reduces potential savings by 10 %.

    Shame todays designers a) dont actually understand how things worksand b) place undue reliance on inaccurate and approximate data.

    Its called progress... :rolleyes:
    • Like Like x 1
  5. S.P.S.

    S.P.S. GSR

    Tradition, the enemy of progress!

    I have been guilty of this in the past, the trouble with being trained by a very old school plumber..

  6. YorkshireDave

    YorkshireDave Plumber Top Contributor!!

    Or physics and doing the job properly...

    The two points of controls are A) to deliver improved comfort conditions and B) to reduce energy consumption. Less effective, less efficient processes (i.e. negating vital contributory factors) deliver neither. Therefore current methods cannot constitute progress no matter how its re-labeled because it's less efficient outcome actively harms our planet.

    If people wish to label that desire to get it right - 'old school' then they are both sadly lacking in intelligence as well as understanding of our Earthly plight.

    Neither our children and or childrens' children will look back and thank us for this greedy laziness. Instead we will be labelled the generations that put profit before lives... What a legacy! :(
  7. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    What about people who can't afford to have anything fancy and have to go with a cheap boiler
    • Like Like x 1
  8. YorkshireDave

    YorkshireDave Plumber Top Contributor!!

    Even simple controls set up correctly and explained properly can save significant amounts and provide reasonable comfort
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