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Re-using the heat in bathwater in Britain

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Re: Re-using the heat in bathwater in Britain

#71

Post by hanoz »

Anthony-G wrote: post #52
wcoenen wrote: post #7

I tried this once on a cold winter day: I let the bath cool down to room temperature (which was <20C) before letting it drain, with the bathroom door open. The result was a lot of condensation on the windows in the surrounding rooms. I figured the high humidity was going to cause more damage than it saved money, so I scrapped the idea.

As a bather, I also tried this idea a couple of years ago. I thought condensation would be an issue but the house I live in seems to have low humidity. The bigger downside for me was having to expend more time and effort cleaning the sides of the bath. This summer, I tried taking cold showers as an alternative energy conservation measure. So far, this Autumn has been very mild in Ireland so I've been able to keep up…

It occurred to me to try this for the first time last week and the extra cleaning thing swung it for me too, which is a pity as there's a good 40 pence worth of heat in that water at current prices. Not sure the wife was going to be too pleased with my used bathwater hanging around all day anyway. Also, probably not a very good idea for anyone with young children in the house.

Re: Re-using the heat in bathwater in Britain

#72

Post by lucb1e »

wcoenen wrote: post #7

I tried this once on a cold winter day: I let the bath cool down to room temperature (which was <20C) before letting it drain, with the bathroom door open. The result was a lot of condensation on the windows in the surrounding rooms. I figured the high humidity was going to cause more damage than it saved money, so I scrapped the idea.

But did it even do anything in the first place? Because if the temperature wasn't measurably raised, it's not even worth considering the 'how to deal with humidity' question that people are discussing.

Re: Re-using the heat in bathwater in Britain

#74

Post by shellfishgene »

wcoenen wrote: post #7

I tried this once on a cold winter day: I let the bath cool down to room temperature (which was <20C) before letting it drain, with the bathroom door open. The result was a lot of condensation on the windows in the surrounding rooms. I figured the high humidity was going to cause more damage than it saved money, so I scrapped the idea.

If you really wanted to do this and remove the moisture problem you could probably cover your tub full off water with a plastic sheet to cool off.

Re: Re-using the heat in bathwater in Britain

#75

Post by sixstringtheory »

zubspace wrote: post #58
ArmandGrillet wrote: post #53

Tangentially related: has someone found something less energy intensive than taking a bath while bringing the same degree of warmth? I've been looking at heated blankets but they're all made of polyester which is not comfortable due to the moisture being trapped under the blanket. Heated seats in some cars are the closest sense of comfort I've found but that technology doesn't seem to exist for regular seats.

Maybe just one or two hot water bottles? [1] We use them in Winter to warm our feet in bed. But they are very versatile and can also be used to alleviate any kind of tension. I also use one while I code: I put it inside of a small (baby-)sleeping bag wrapped around my feet. Sounds weird, but it's so comfortable! [1] https://www.google.com/search?q=hot+water+bottle&tbm=isch

We use this trick on winter backcountry camping trips to good effect. After dinner, melt snow to a boil and fill up all our water bottles and bring them in the sleeping bag. Every little bit helps!

Re: Re-using the heat in bathwater in Britain

#76

Post by shellfishgene »

afandian wrote: post #40
maherbeg wrote: post #11

I was actually looking at heat recuperation systems for bathrooms recently and stumbled upon https://ecodrain.com/en/ - if we hadn’t already remodeled our bathrooms I’d have loved to have installed this. For now we make do with a heat pump water heater which is very efficient.

I wonder how different it would be to use an off the shelf heat exchanger, e.g. this one? https://www.ebay.co.uk/itm/263272702860 You'd probably have to filter the shower water before sending it through, but beyond that I wonder how different the principle is. Maybe being easy to clean is a significant factor in drain showers.

There may also be problems with sanitation rules, only a minimum of water should sit in the pipes, and then ideally hot our cold but not luke warm.

Re: Re-using the heat in bathwater in Britain

#78

Post by est31 »

yrgulation wrote: post #62
HPsquared wrote: post #54

Earlier quoted context omitted.

If I was planning national energy infrastructure, I wouldn't plan on dividing the equipment into a million tiny pieces and installing it on roofs, of all places. It seems much simpler to manage a solar farm than 10,000 roofs.

Why not both tho? Energy issues arent limited to capture and storage, it involves distribution as well. Plus you want energy to be dirt cheap and accessible. So the more the better.

Solar farms are more economic to build than rooftop solar: https://www.nrel.gov/news/program/2021/documenting-a-decade-...

For individuals the calculation might be different as rooftop solar makes you less dependent on price trends you have no influence over, but as a society, utility solar is less expensive.

Re: Re-using the heat in bathwater in Britain

#79

Post by sixstringtheory »

upsidesinclude wrote: post #69

Turning your thermostat down by one or two degrees per week and getting acclamation to cold is a better alternative. 5 degrees on the thermostat would be a far better measure than tub heat. Short showers, or 'sea showers', to conserve water and heating would likewise be a far better option than a 50 gallon bath.

And not just short showers, but managing the amount of time the water is actually running. Here’s my strategy for an efficient shower:

1. turn on the water, get in, rinse down, soak a wash cloth

2. turn off water

3. lather hair with shampoo

4. lather wash cloth with soap and scrub body

5. turn on water and rinse down

The majority of the time we’re standing in the shower, we don’t actually need the water to be running.

Re: Re-using the heat in bathwater in Britain

#80

Post by ytdytvhxgydvhh »

I appreciate this attitude:

> Should you do this?

> I render no judgment!

> But here’s a thought: It’s OK to use energy for convenience. This is true even in a time of crisis. After all, only a small fraction of the energy we use is necessary to stay alive. We could live dirty and shivering in dark rooms, eating oats and only moving around on foot. But no one does. So the question is how much energy you want to use for how much convenience.

Too many articles or conversations about energy usage seem to take an attitude more like, “if you’re not doing the thing we say is the solution then you’re the problem”.

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