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Sales hype?

Discussion in 'Science' started by Moony, Feb 6, 2012.

  1. Moony

    Moony Lead commenter

    Maybe they are refering to it having greater efficiency. If thats the case then it's not wasting energy.....but then wasted energy in electrial appliances tends to be heat but a heater is designed to make heat. Seems very odd.
  2. DonutBoy99

    DonutBoy99 New commenter

    Sounds like it relates to efficiency.
    Perhaps the higher surface area to volume ratio means heat from the hot (lower volume of) water inside is more readily dumped into the room.
    What that means to the heat energy still in the water and thus available for the next radiator in the circuit I don't know...[​IMG]
  3. Given that radiators are connected to a closed system, once it is "full" the volume of water doesn't change (I'm ignoring expansion, overflow pipes etc). So "saving water" probably amounts to a pint every 5y.
    The amount of energy carried around the system depends on the amount of water and its temperature (also the specific heat capacity, but if everyone is using water, we can ignore that). A low mass system will get hot faster than a high mass system, so presumably heat will start to flow into the room in less time from start-up. It will also cool quicker, so don't switch off 30mins before you go to bed.
    Assuming your boiler "throws out" water at a fixed temperature, you will have to pump more water round the system to put the same amount of energy into the house. Either the pump will have to work faster (more chance of a mechanical problem) or the water will have to flow for longer, which seems to imply the boiler being on more.
    (I'm getting a bit concerned here, because my first thoughts were that it could be more efficient: however, with the same initial water temperature, the returning water will be cooler. Is it a case of the original cold water heating up faster and the efficiency gain comes in those transient phases which we tend to ignore? Similarly in the shut-down stage?)
    My other thought was that the boiler would "cycle" (switch on and off) more frequently. This would therefore keep the temperature more uniform in your house - it can be done with electronic temperature sensors and tends to be recommended.
    On reflection, I suspect sales hype just about sums it up. I haven't looked at their website but I certainly wouldn't pay 10% more than for a standard radiator and I think they should be cheaper - less water so less metal (but new tools, limited market?)
  4. T34

    T34 Established commenter

    Well, everyone seems to agree with me that it's a bit of a mystery, what <u>are</u> they talkng about?
    How would you define the efficiency of a radiator? ...(useful energy out/energy in)?
    The water is going around the circuit, so any energy it has retained on the first cycle will be available for the next. It's heat we're talking about, good old fashioned heat. The easy form of energy. There's no way that heat can be "wasted" in a heating circuit - 'cos the point of a heating circuit is...to waste heat.
    Do you think it is worth my while to raise it at my local Wickes branch?
    (only joking).
  5. DonutBoy99

    DonutBoy99 New commenter

    Heat can be wasted, if it doesn't end updoing the useful job of heating the room, e.g. hot exhaust gas from your boiler.
  6. T34

    T34 Established commenter

    Very true, but I did say "There's no way that heat can be "wasted" in a heating circuit".
    I suppose it could be lost from the connecting pipes. Mine aren't lagged. Poor practice, IMO.

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