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Cold is the presence of low temperature, especially in the atmosphere. In common usage, cold is often a subjective perception. A lower bound to temperature is absolute zero, defined as 0.00 K on the Kelvin scale, an absolute thermodynamic temperature scale. This corresponds to −273.15 °C on the Celsius scale, −459.67 °F on the Fahrenheit scale, and 0.00 °R on the Rankine scale.
Since temperature relates to the thermal energy held by an object or a sample of matter, which is the kinetic energy of the random motion of the particle constituents of matter, an object will have less thermal energy when it is colder and more when it is hotter. If it were possible to cool a system to absolute zero, all motion of the particles in a sample of matter would cease and they would be at complete rest in this classical sense. The object would be described as having zero thermal energy. Microscopically in the description of quantum mechanics, however, matter still has zero-point energy even at absolute zero, because of the uncertainty principle.

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  1. K123456

    How far can slab cold water inlet be from shower tap - 1200mm?

    The hole in the slab for cold water shower tap inlet is 1200mm away from where it needs to be. Is this a problem? The bathroom is on the second storey (concrete slab) and it looks like the builders may have put the plumbing for the shower inlet about 1200mm away from where it needs to be. Is...
  2. mjtefc

    10mm not 15mm cold water to fridge

    Divy here thought his cold water feed was 15mm.. so bought a 15mm - 1/4" reducing tee to plumb a fridge. It's 10mm!! I've already cut it so stuck a stop end on. What options do I have as I can't find a 10mm - 1/4" reducing tee... Do I get some 15mm pipe and use 15mm - 10mm reducers ?
  3. S

    If i remove a radiator in the living room will there be a cold spot?

    Hi, We currently have 3 old radiators in our living room, the room feels cold in winter and radiators take ages to get warm, system has been power flushed and new pump fitted, so want to replace the radiators. The room is 5.7 x 4.9m x 2.5m but heat vents upstairs to a landing with no radiator...
  4. A

    URGENT problem with water flow in a new mixer tap

    Had a new bathroom fitter, and the sink has these taps on Ideal Standard Tesi 1 lever Chrome effect Deck Mono Mixer Tap. The hot and cold water flow is reduced. But when the fitter took the taps off the water flow was increased, Could there be a problem with the new taps or is this because they...
  5. N

    Lost cold water in kitchen

    Hi guys installed a outside garden tap seemed to go well until I went back to the kitchen only to find I have no cold water now the hot water works fine and upstairs is normal hot and cold except for kitchen I'm baffled what's going on please help Thanks
  6. E

    Shower off combi running hot and cold

    I have a combi Halstead HE 30 in my loft, the past few days the gravity fed power shower runs between hot and cold The sink hot water taps are ok as far as I can tell, I have mixer taps. I look at the boiler code as the sink taps run, it stays on H, but when I use the shower, it switches...
  7. M

    Mass of gunge in cold water storage cistern.

    Hi all. Hope you are enjoying the sunshine and hope no one is working in lofts at mo. Anyone seen this gunk before in a cold water storage cistern?
  8. P

    how do I fix the cold water faucet that is barely running?

    My upstairs cold water faucet just barely streams out.. The cold and the hot in the shower are fine but not the cold water of the sink. Is there anything I can do myself without calling for a costly pllumber?
  9. omendata

    Blocked Cold Water Tank Pipes - Doing my head in for over a year

    Ok I have been dealing with this problem for over a year and finally have to ask for some help as backflushing every 2 weeks or so is getting very tiresome. I live in a 60's flat (3 flats per side of the block so 6 flats in all) with two overhead water tanks in a tankhouse on the flat roof for...
  10. T

    Megaflo cold feed hammering.

    Afternoon all, I’ve recently started getting a loud vibration coming from the cold feed. Only when I’ve got the hot tap on. Any ideas what it could be? I’ve managed to stop the vibration by turning the blue valve slightly. Thanks in advance.
  11. Bazza1687

    Shower runs cold when hot taps used

    Hello, I have just installed a new shower which works well, however if you open a hot tap anywhere else in the house the shower runs cold, however if I open a cold taps the temperature does not change. I believe my shower is only a mixer not thermostatic did not do my research when buying the...
  12. P

    Heatpump Hot on Gas Side But Cold On Wet Side?

    Mitsubishi Ecodan 2011 8.5kw Hy Guys, I have just installed a second hand ecodan, all seemed to be going well until i noticed that the flow temp doesn't increase much, infact 2 degrees in 40 mins, then the pump shut off with a over temperature warning on the gas side. I have it piped up to a...
  13. J

    radiators cold at the bottom

    Our newly bought house doesnt have a filter on the combi and most of the radiators (microbore) dont heat up at the bottom which im putting down to sludge and other gunk i intend to fit a filter (not sure which 1 yet) and run some clearer through it (fernox f3 has been recommended) i am also...
  14. W

    URGENT Why does my shower keerunning hot and cold

    Why does my shower keep running hot and cold
  15. K

    new boiler just in, HW from shower goes cold after (5-10 mins),

  16. RichardWoking

    Cold water overwhelming hot to showers

    Recently 2 of my showers stopped producing hot water following a plumber refitting another of my ensuites. The 2 showers in question are pumped with a Salamander twin house pump. Hot is reaching the showers (hot feed to mixer is hot), yet both showers are luke warm, at best. The other recently...
  17. J

    To insulate both hot and cold pipes?

    Hi all, I just learned the external pipes for boiler system should be insulated especially in loft and garage as they are in very cold area. I checked my loft and found some pipes are insulated but others are not! I think it is because the insulated pipes are from previous owner's, since I...
  18. M

    Grohe shower unable to get warm/hot

    Hi My daughter has a Grohe mixer shower (see photos) and however I try to mix it to warm / hot it only just manages slightly warm or cold. I don't know how old it is as it was already fitted when they moved in. Can anyone suggest what might be the problem. Other showers are fine so I think it's...
  19. A

    Capping old hot and cold pipes

    Looking for some opinions on whether you should cap old hot and cold water pipes. A plumber I got to remove some old sinks from bedrooms has capped off the hot and cold pipes under the floor. I thought it didn’t quite seem like the best thing to do and thought he would completely remove the...
  20. F

    Hot feed from twin pump stalls when cold feed starts in bath mixer tap

    Hello All, Hoping for a bit of advice/info in this one: My Setup Small system in apartment with cold tank above hot tank in the hotpress, so fairly low head pressure. Installed a pump about 15 years ago and worked fine until last week (original pump was an Stuart Turner ST55 replaced after...