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.

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.

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)

Very rarely used property you can get temperature swings underground. 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.

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.

That’s likely overly cautious. 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.

> 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....

[2] 1962 source: https://nrc-publications.canada.ca/eng/view/ft/?id=15f6f5eb-...

I agree they need to bury it nearly that depth but while IPC 2018 section 305.4 puts water pipes at least six inches below the frost line many places increase that to 12” for water and or sewer.

I don’t know much about how Canada does things.

Yeah, you really don't want those sewer lines freezing...

I'm very confused at the lash back you're getting. Have you all never seen the pipes freeze? Or worse: burst? They wouldn't do that if they didn't swing in temperature. I'm not convinced of SEC's 2-3x estimated increase but the claim that water temperature delivered to your taps vary in temperature is an objective fact. Of course different areas have different infrastructure and can be more resistant to freezing and rupture, but turn on the cold water in the dead of winter and you'll find it is a lot colder than in summer.

I agree water temperature at the tap can vary quite a bit. My parents place has the water go through an unheated crawl space and they would regularly keep the tap on to avoid the pipes freezing when temperatures got unusually cold. Further many municipalities extract water from rivers which experience significant seasonal variation etc.

My comment was simply in reference to well water which has very consistent temperature and will warm or cool the soil surrounding pipes at any reasonable depth if you are using water regularly.

The original point was that a shower would have to use more energy to heat shower water in winter. Not sure now how any of your comments relate to that - do you agree with it?

The relationship is many people don’t experience that. Aka it’s a you might experience X not a you will experience X.

A poster mentioned failing to get a cold shower in Singapore, but Singapores ground temperatures are much higher than we are used so well water is going to be ~25C year round and tap water can be significantly warmer than that.

People don't experience it because the water heater output is a consistent temperature. There's nothing to experience with increased consumption of electric/gas/heating oil, especially when those concurrently increase for home heating

That assumes the water going into the water heater changes temperatures which as I just said isn’t always the case. Some people take “cold” showers year round and the tap is very consistent.

Trivially people in the tropics don’t have a winter, but well water can similarly have very consistent temperatures independent of seasons.

> I'm not convinced of SEC's 2-3x estimated increase

It's a simple calculation, but very location specific. In my particular case, if the water heater is set to 50C, and tap water is 22C in Summer, it has to impart a ΔT of 28C. If your tap water is 4C in winter, the ΔT is 46C. Not quite double, but close to it. If your water heater is in a poorly conditioned space, then it would lose considerably more heat to the surrounding space when outside temperatures are -15C than when outside temps are 35C. All told, hot water energy usage for my particular situation is between 2x and 3x. Other situations would vary, but still significant.

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.

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!

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?

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.

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.

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.

> SE Asia where you can drink the tap water

A very verbose way of saying Singapore.

Your way is more verbose, by two characters to be exact.

You can drink it other countries! It's risky, but you can drink it!

Taiwan, Japan, Singapore. Only countries you can safely drink tap water in Asia AFAIK.

Also South Korea, Brunei and Hong Kong (apparently).

But I have friends who rinse their mouth, brush with tap water in Vietnam and haven't gotten sick. It obviously varies a lot by which city (or even within the city), but the water is tested and obviously highly chlorinated (by smell).

I mean, I wouldn't drink it regularly because I don't think they look for non-biologic toxins like metals.

I've rinsed my mouth in most countries in SEA. But never drink it. In Taiwan you can drink tap water but vast majority of people boil it because apparently alot of the pipes in homes are old so they boil it first. Sometimes I'm lazy and don't want warm water so I just fill my bottle with tap water.

In Arizona, "cold" water at the tap can easily be in the neighborhood of 100F/37C all summer. We kept a water filter pitcher in the fridge for drinking water, so it wasn't really a problem there, but it did make it impossible to take a truly cool shower or follow a recipe that instructs you to rinse something in cold water.

I grew up in AZ.. just run the water until it cools down. Unless your showering from an outside hose it'll be 50 degrees just from being underground. If you aren't getting that then something is very wrong with your plumbing I'd recon. Like, the tap intake comes into the house after the swap cooler on the roof kind of thing. Plus the evap after the shower.. that'll cool you off.

You sure it'll be 50 deg? that's significantly colder than summer tap water in my Canadian city, which is closer to 70F at peak.

Not sure where you grew up, but most of the population gets tap water from the CAP, which means the water ran for hundreds of miles in canals across the desert before going into a water treatment plant. It’s 90F+ easily in the summer in any modern builds in Tuscon/Phoenix.

Cap water is recharged into the groundwater aquifers.

Also you’ll notice no water towers.

And it’s Tucson… not Tuscon.

> Cap water is recharged into the groundwater aquifers.

Not as part of the “to tap” process.

> Also you’ll notice no water towers.

Not relevant. CAP boosts elevation many times. A water tower is needed if you don’t have a high pressure water source like the CAP canals.

> And it’s Tucson… not Tuscon.

Don’t emotionally lash out with irrelevant shit. Focus on the content, not the presentation.

>> And it’s Tucson… not Tuscon.

>Don’t emotionally lash out with irrelevant shit. Focus on the content, not the presentation.

If you can't even get the spelling of a major city in Arizona correct, your content is... as the kids like to say, "sus".

You’re still struggling to grasp any of the content. Your whole reply is only focused the response to your unrelated spelling dunk.

Having such superficial interactions with the world is congruent with believing the meme that all of Arizona drinks well water though.

I hope you do take some time some day to learn about the state you grew up in. The water projects are quite impressive engineering because there is no other option. The rural holdouts that pumped their groundwater dry learned that lesson the hard way.

Look dude it is you who doesn't understand how it works, at least as far as it concerns Tucson: https://storymaps.arcgis.com/stories/70f626809fd84e228c0f32a... https://www.tucsonaz.gov/files/water/docs/coloradoriver.pdf

They tried "to the tap" and it pissed everyone off because the river water leeched out all of the rust in people's pipes.

Water lines in Arizona single family homes are very commonly routed through the attic, where they can get very hot, so your imagined scenario isn't really that far off from reality for a lot of people.

I don't know how many gallons I would have to waste to get the tap to start delivering water at 50°F. I could run the faucet for several minutes and still get water that was body temperature or warmer.

> Strangely enough, drinking water is served at temperatures up to 100C in certain preparations (eg tea)!

It's prepared at 100C, and _may_ be served at 100C, but it does not enter your body at 100C or you will burn your mouth.

> 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.

It may be drinkable, but temperatures above 25C will be a cesspit for legionella.

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