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Living in Germany and getting both my heating and hot water from natural gas I regulary track my gas consumption throughout the different seasons. With 1-2 show

Living in Germany and getting both my heating and hot water from natural gas I regulary track my gas consumption throughout the different seasons. With 1-2 showers per day in the household my daily natural gas consumption in winter is about 20x higher than in summer, so compared to heating the house the energy in the hot water is a drop in the bucket.

michal8181 4y ago
Same here (I live in Poland). 2 + 2 family with small kids. Hot water is 5% of my overall gas bills. Rest is heating.
SECProto 4y ago
Note that a portion of that increase in gas consumption is still due to the hot water usage, even if the number and duration of showers stays the same - tap water varies in temperature through the year, getting colder in winter and warmer in summer. In my case, it varies between ~5 and ~22C. Germany has milder winter temperatures so likely not as much variation, but still a significant fraction of the temperature increase imparted by your water boiler. Additionally, if you have a hot water tank (as opposed to on demand), then the tank has to work harder to maintain temperature (assuming you maintain the indoor air temperature differently in winter than summer). All combined, that might account for a 2 to 3 fold increase, the rest of it would be caused by space heating.
- Retric 4y ago
  Well water stays very consistent year round in most areas. Some municipal systems vary more depending on where they get it and how they store it. Water towers used to smooth out water demand for example can noticeably impact water temperatures.
  - SECProto 4y ago
    Temperature at the well stays consistent, but it can vary at the tap. At a family member's secondary property, tap water will vary from 2 deg in winter up to 15 in summer (because the line between the well and the house is only ~3-4 feet deep, and surface temperature changes a lot). If we were drawing more or less/line was different length/different depth, the variation would change. (I know all these values from homebrewing, where water temperature plays a big role in how long it takes to cool)
    - Retric 4y ago
      Very rarely used property you can get temperature swings underground next to these pipes. But in normal domestic or municipal settings the regular water through the pipes is going to equalize temperatures year round to within a fraction of a degree at 3-4 feet underground outside of extremely long runs. Also of note, ~25feet of one inch pipe holds 1 gallon of water. So there can be quite a bit of lag involved, but water is unlikely to spend that long in these pipes to change temperature. Thus the ground temperature would need to be extremely different to make a significant difference once the temperature equalized.
      - SECProto 4y ago
        The various municipalities I've lived in require 5 to 8 feet minimum bury depth for water pipes to avoid freezing. The seasonal property I mentioned earlier being at 3-4 feet depth is likely helped by the fact that snow is not cleared above the run (additional insulation) and it is in one of the milder climate areas where a municipal spec water run would only need 5 feet of bury. It may also have half inch of foam wrap for insulation, I'm not sure. Agree on the pipe volumes.
        Retric 4y ago
        That’s likely overly cautious. https://www.hammerpedia.com/frost-line-map/ https://www.hammerpedia.com/frost-line-map/ That said, municipality’s will often be overly cautious and they do need to consider property siting abandoned.
        SECProto 4y ago
        > That’s likely overly cautious I'm not in the country shown on your map. The area of Canada I'm in would be somewhere roughly around the 90" line on that map. It's between the 2000 and 2500 lines on this map [1] (the seasonal property is around a 1500 contour) The municipalities pay for the main to be installed. They wouldn't spec it to be 8' (2.4m) deep if it didn't need to be. edit: the contours in my source are not mm of freezing depth, but degree-days of freezing. However, 2500 DDOF corresponds[2] with 70" of frost penetration, while the 1500 DDOF corresponds with 55". So the required bury depths are slightly but not significantly conservative [1] https://www.urecon.com/applications/images/canadian_map_lrg.jpg https://www.urecon.com/applications/images/canadian_map_lrg.... [2] 1962 source: https://nrc-publications.canada.ca/eng/view/ft/?id=15f6f5eb-a070-4327-aec4-71472a903119 https://nrc-publications.canada.ca/eng/view/ft/?id=15f6f5eb-...
  - _nalply 4y ago
    Once in Singapore when I was invited by a friend in a highrise flat I wanted to have a cold shower. However the cold water was still very warm and I didn't feel refreshed. I think the tropical sun warmed up the water in the pipes in the walls.
    - yurishimo 4y ago
      Where do they store the water? In NYC it's not uncommon for a building to have a holding tank on the roof of the building and then use gravity to supply "pressure" to the units in the building. If Singapore does something similar, it would be logical that the water would be warmer. I lived on the top floor in a newer building in Dallas that pumped water the entire way and the pressure was noticeably less in my apartment than in the gym on the ground floor. The water was "cold" though!
- alkonaut 4y ago
  22 degrees is the coldest tap water? That means you basically need ice cubes or fridge storage before you can drink it in the summer?
  - SECProto 4y ago
    Strangely enough, drinking water is served at temperatures up to 100C in certain preparations (eg tea)! Less tongue in cheek, yes, people will often chill their tap water in the summer before drinking. But it's perfectly drinkable at whatever temperature it comes out of the tap. The water supply in my locality comes from a surface reservoir, leading to the higher summer temperatures.
    - alkonaut 4y ago
      I just never reflected on the idea that cold tap water in summer is quite luxurious. I have that but I have no idea why tbh.
      - refurb 4y ago
        Indeed. Having living in SE Asia where you can drink the tap water, it’s rough getting a glass of water from the tap and it’s 25C. There is no “cold” tap, just warm and hot taps.
        zarzavat 4y ago
        > SE Asia where you can drink the tap water A very verbose way of saying Singapore.
        seba_dos1 4y ago
        Your way is more verbose, by two characters to be exact.
        refurb 4y ago
        You can drink it other countries! It's risky, but you can drink it!

michal8181 4y ago

Same here (I live in Poland). 2 + 2 family with small kids. Hot water is 5% of my overall gas bills. Rest is heating.

SECProto 4y ago

Note that a portion of that increase in gas consumption is still due to the hot water usage, even if the number and duration of showers stays the same - tap water varies in temperature through the year, getting colder in winter and warmer in summer. In my case, it varies between ~5 and ~22C. Germany has milder winter temperatures so likely not as much variation, but still a significant fraction of the temperature increase imparted by your water boiler. Additionally, if you have a hot water tank (as opposed to on demand), then the tank has to work harder to maintain temperature (assuming you maintain the indoor air temperature differently in winter than summer). All combined, that might account for a 2 to 3 fold increase, the rest of it would be caused by space heating.

Retric 4y ago
Well water stays very consistent year round in most areas. Some municipal systems vary more depending on where they get it and how they store it. Water towers used to smooth out water demand for example can noticeably impact water temperatures.
- SECProto 4y ago
  Temperature at the well stays consistent, but it can vary at the tap. At a family member's secondary property, tap water will vary from 2 deg in winter up to 15 in summer (because the line between the well and the house is only ~3-4 feet deep, and surface temperature changes a lot). If we were drawing more or less/line was different length/different depth, the variation would change. (I know all these values from homebrewing, where water temperature plays a big role in how long it takes to cool)
  - Retric 4y ago
    Very rarely used property you can get temperature swings underground next to these pipes. But in normal domestic or municipal settings the regular water through the pipes is going to equalize temperatures year round to within a fraction of a degree at 3-4 feet underground outside of extremely long runs. Also of note, ~25feet of one inch pipe holds 1 gallon of water. So there can be quite a bit of lag involved, but water is unlikely to spend that long in these pipes to change temperature. Thus the ground temperature would need to be extremely different to make a significant difference once the temperature equalized.
    - SECProto 4y ago
      The various municipalities I've lived in require 5 to 8 feet minimum bury depth for water pipes to avoid freezing. The seasonal property I mentioned earlier being at 3-4 feet depth is likely helped by the fact that snow is not cleared above the run (additional insulation) and it is in one of the milder climate areas where a municipal spec water run would only need 5 feet of bury. It may also have half inch of foam wrap for insulation, I'm not sure. Agree on the pipe volumes.
      - Retric 4y ago
        That’s likely overly cautious. https://www.hammerpedia.com/frost-line-map/ https://www.hammerpedia.com/frost-line-map/ That said, municipality’s will often be overly cautious and they do need to consider property siting abandoned.
        SECProto 4y ago
        > That’s likely overly cautious I'm not in the country shown on your map. The area of Canada I'm in would be somewhere roughly around the 90" line on that map. It's between the 2000 and 2500 lines on this map [1] (the seasonal property is around a 1500 contour) The municipalities pay for the main to be installed. They wouldn't spec it to be 8' (2.4m) deep if it didn't need to be. edit: the contours in my source are not mm of freezing depth, but degree-days of freezing. However, 2500 DDOF corresponds[2] with 70" of frost penetration, while the 1500 DDOF corresponds with 55". So the required bury depths are slightly but not significantly conservative [1] https://www.urecon.com/applications/images/canadian_map_lrg.jpg https://www.urecon.com/applications/images/canadian_map_lrg.... [2] 1962 source: https://nrc-publications.canada.ca/eng/view/ft/?id=15f6f5eb-a070-4327-aec4-71472a903119 https://nrc-publications.canada.ca/eng/view/ft/?id=15f6f5eb-...
- _nalply 4y ago
  Once in Singapore when I was invited by a friend in a highrise flat I wanted to have a cold shower. However the cold water was still very warm and I didn't feel refreshed. I think the tropical sun warmed up the water in the pipes in the walls.
  - yurishimo 4y ago
    Where do they store the water? In NYC it's not uncommon for a building to have a holding tank on the roof of the building and then use gravity to supply "pressure" to the units in the building. If Singapore does something similar, it would be logical that the water would be warmer. I lived on the top floor in a newer building in Dallas that pumped water the entire way and the pressure was noticeably less in my apartment than in the gym on the ground floor. The water was "cold" though!
alkonaut 4y ago
22 degrees is the coldest tap water? That means you basically need ice cubes or fridge storage before you can drink it in the summer?
- SECProto 4y ago
  Strangely enough, drinking water is served at temperatures up to 100C in certain preparations (eg tea)! Less tongue in cheek, yes, people will often chill their tap water in the summer before drinking. But it's perfectly drinkable at whatever temperature it comes out of the tap. The water supply in my locality comes from a surface reservoir, leading to the higher summer temperatures.
  - alkonaut 4y ago
    I just never reflected on the idea that cold tap water in summer is quite luxurious. I have that but I have no idea why tbh.
    - refurb 4y ago
      Indeed. Having living in SE Asia where you can drink the tap water, it’s rough getting a glass of water from the tap and it’s 25C. There is no “cold” tap, just warm and hot taps.
      - zarzavat 4y ago
        > SE Asia where you can drink the tap water A very verbose way of saying Singapore.
        seba_dos1 4y ago
        Your way is more verbose, by two characters to be exact.
        refurb 4y ago
        You can drink it other countries! It's risky, but you can drink it!