For real. Everytime I get in the shower I end up having to point the showerhead away and cower from the cold water and I could have just turned it on first?
this post was submitted on 19 Jun 2025
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I'm so thrown off by our current shower which legit heats up in 2 seconds. I was so used to waiting like a minute for it to warm up, I built my rituals around that. But this one... it's just hot, like right away. Bizarre
In fancy installs, the hot water supply is a loop, not a tree, and a circulating pump keeps the entire run hot.
That sounds like a great way to waste energy.
Sorry, you've met wealthy people, right...?
It's just dumb engineering to heat up a pipe the entire day for the 0.8% of the day you need it to be hot.
Heat pumps generally use a lot less power. Don't need to heat up much if it is already slightly hot.
Insulation + retaining heat means it isn't nearly as energy inefficient as you think.
They keep the water tanks heated all day, and not heating the pipes means they have to do more work as they are drained of more water to fill the length of pipe to the shower which will then lose that heat over the course the day, only to need the water heater to heat it back up again.
With enough insulation, anything can meet energy-efficiency standards. XD
It’s typically used for large complexes like campuses where the hot water is made en masse in one building and the loop goes around all the other buildings. Helps keep cost down (at construction) because you only need one giant water heater. Helps not have to wait 10 minutes to bring the hot water to your building. Energy still gets wasted but given the number of users, not that bad.
You don’t have to heat it up all day. Did you just post the first “anti” thought you had without giving one minute of consideration to how modern controls work?
Have you read the previous comments? Because that's exactly what's implied.
Someone else already pointed out that these are usually pretty well insulated systems that don't radiate much energy, but also consider how many dozens of gallons of water aren't being wasted by waiting for it to be warm.
Nearly all of these systems are put on timers. So they stop cycling while you're at work or over night. They'll often make it a part of the smart home ecosystem as well, so you can override from a smart home device or phone
If you have a hot water tank, that hot water is just sitting there getting cold just waiting to be heated up again. A circulating pump puts that hot water to use by circulating it through the pipes, which has a nice side effect in cold climates of preventing the pipes from freezing and bursting. I doubt it wastes much energy as you think.
Hot water tanks do not just “get cold”; they are fantastically well insulated. And a great way to lower peak energy usage by accumulating heating power, making it possible to use a heat pump to heat the water.
Hot water tanks are usually not that well insulated. If you want to save electricity an easy thing to wrap a good later insulation around it.
Rather than just dumping the cold water down the drain?
A huge amount of waste https://www.youtube.com/watch?v=67i4-_sXGcQ Claims $400/year, $35/month.
I think some of the really fancy installs have a secondary tankless water heater for the shower....
I think I saw that somewhere.
The distance from the heater to the shower is usually the biggest factor.
Same here! Moved to an appartement so everything is closer and now I don't need to turn on the shower 5 business days before I want to shower
Some apartments with central hot water have a recirculation pump, so the water is almost always hot. My building has one. The water is always hot, but for some fucking reason the hot water is like right next to the cold water, but the cold water doesn't have a pump, so the cold water pipes will get hot from the flowing hot water. Then when I turn on my shower the cold water will be just as hot as the hot water... for like a minute, making the entire thing fucking pointless because you still have to wait to get in. But I can burn myself on demand so I've got that going for me.
I have my own water heater. Its an older appartment 😅 but that does sound quite inconvenient wow
I'm in a SFH but all the bathrooms are very proximal to the heater so it slaps