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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. Zach054

    Balanced Cold. Electric Shower.

    Good Afternoon. Just wondering if it would be fine to connect an electric shower to the balanced cold supply from an unvented cylinder. Replacing an old Bath mixer tap with the shower hose built into it. Regards
  2. C

    Bar Shower hot on right cold on left

    Hi everyone, I am looking to see if anyone has purchased a bar shower where the hot is incoming from the right and cold coming from the left, really struggling to find a bar shower and riser kit to accommodate this, any advice be much appreciated thanks
  3. R

    Unvented cylinder no cold water to multiple outlets

    Hi, I’m having issues with cold water to multiple outlets. Taps, showers, toilets cold water is fine at the kitchen sink. The hot water system is a Glenhill unvented cylinder. Hot water is fine at all outlets. I assumed the cold outlets not working were from the balanced cold from the...
  4. M

    Heat pump unvented install balanced cold

    If changing a combi boiler system to a heat pump. What do they usually do with the balanced cold connection on the hot water cylinder? Cap it. And put a pressure reducer on the mains so they have equal hot and cold pressures? I can't see them repiping a balanced cold from the cylinder to each...
  5. M

    15/22mm cold feed to boiler

    I'm in a house with the cold feed coming up in the kitchen. In 25mm mdpe. The boiler is in the garage adjacent. I plan on running the cold from the sink in the kitchen under the kitchen units to the garage to feed to boiler. And the 15mm coming back from the boiler to the sink. Would there be...
  6. marco128

    Thermostatic Shower cold

    Hi, Recently noticed an issue with thermostatic shower that was determined to get sorted. The shower would drop (which got worse) and would not maintain temperature,due to water quality here and visible limescale in cartridges,decide to just replace entire shower for a nice new one. This...
  7. dingledow

    Cap off cold water running to shower via loft space?

    I’m doing a bathroom refit, and there’s some strange pipework design that I’d like some advice on, please. I want to remove the cold water pipe running through the loft space because I would rather avoid having a cold water pipe buried under the loft roll insulation. Instead, I’d like to reuse...
  8. Andy110983

    New Triton shower cold

    Hi, I had a Madrid 2 Triton shower, I had it for 6 years then one day it started to run cold, so I purchased a Triton Seville shower and changed them over, that was running great for 3 days and now that has gone freezing cold, any advice? Thank you
  9. C

    2 cold feeds to indirect hot water tank

    Hi, I am reinstating an indirect hot water tank and have 2 cold water feeds coming into it from the same supply. One of the feeds has a float valve but what ever was on the other has been removed. Why would there be 2 feeds to the top of the tank? Can I blank one off and just use the float valve...
  10. tigersb

    Cold Radiator and towel rail

    I have a caravan with a brand new heating system.The Valliant combi boiler is working fine but one radiator and one towel rail are stone cold.I have bled both and also tried to balance the radiators with no success.Even when I shut off all other radiators the problematic ones still don't heat...
  11. Crossfingers

    Cause of cold shower

    Hi I fitted a low pressure shower set when I had a low pressure open vented system, which has a very low pressure rating. I now have a combi boiler with good pressure. I was wondering if having a shower set with a too low pressure rating could cause predominantly cold water to come out? The...
  12. jamesa2487

    One Cold Radiator Downstairs

    Hi. I have one radiator downstairs that will just not get hot. If I disconnect the thermostatic valve then turn it on hot water comes through. When I reconnect it the radiator heats up for a couple of days then stops again. I have bleed the radiators / balanced. Any idea? Thanks
  13. B

    Cold Rad's & return cool on another rad

    Sorry I have sort of asked this before, tried professionals but not great 1st experience hence DIY attempt attempt again. 2 completely cold rad's, another one get pretty warm, flow pipe hot, return v.luke warm. (Both rad's I have manually flushed really well) Hot water works fine, boiler return...
  14. B

    Shower going cold, hot water supply gets cut off completely?

    I have a new shower that has worked fine, albeit with low hot water pressure, for a couple of months. Now it starts hot, but then goes cold completely, sometimes after a couple of minutes, sometimes after less than 30 seconds. Meanwhile, on the side of the bathroom sink, there are no issues...
  15. A

    Kitchen tap running hot and cold

    Hi all We have an issue with a kitchen tap it seems to run hot and cold or Luke warm all the the other taps in the house are fine it’s just this one tap. It is a mixer tap and the combi boiler is about 2 metres away. It’s a Worcester greenstar. Is this an issue with the tap itself or something...
  16. F

    Combined vent and cold feed

    Hi guys Is it normal for the cold feed pipe from the f&e tank to be combined with the open vent? The cold feed connects to a 22mm tee one end is the vent the other cold feed to rads I thought the vent connects to ch flow and the feed to ch return? Thanks in advance
  17. V

    No cold water in bathroom.indirect water supply.

    Hi.. I would appreciate your advice. I am not get any cold water on the bathroom. Just dribbles in the bath and toilet..none at all on the wash basin. The supply is from the cold water tank. Thank you.
  18. S

    Window seal and gaps need filling too cold

    My house seems to be freezing and my double pvc glazing windows were installed over 20 years ago. The window seals have seen better days and there's gaps in between the window frames and window. Not really done anything like this before as I am not a plumber or carpenter. Does anyone which...
  19. E

    New column rad cold devastated

    New double panel column radiator Cold Turned off all rads not helped Checked trv pin seems fine Locksheild i think is ok see pic sttached Its new so didnt need to flush Cant really balance because the only thing that is hot is the copper pipes So instructions came with it about how it...
  20. BulkWorkwear

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