Hot Water

[2scoops0406]

I've trawled through Google and looked through the forums etc, but can't find an opinion let alone a well thought out answer to the debate I often come across. THe question is this :-

Is it better to keep hot water in a hot water storage tank constantly hot. Or is it better / cheaper / less damaging to the system to let is cool down and reheat it (i.e. put it on timed ?)

For arguments sake, we'll say its a foam insulated copper tank, not scaled, elements in good condition.

I suppose I could try to perform the calormetric calculations, but 1) I can't be bothered 2) They'd be riddled with assumptions.

Anyhow, look forward to your opinions, I've heard arguments both ways.

 

[kevplumb]

if you put it on timed with a well insulated cylinder you wont lose much heat say overnight !
methinks you have got the can opener out again eddie

 

[IanDB]

My tenpennyworth:-

What do you mean by "better"? If you mean more cost effective then it's probably cheaper to switch the tank off when it's not going to be used for a period of time (overnight, during the day if you're at work).

You're always going to get heat loss and the hotter the tank the greater the loss so if you're not using the water you will just be doing your bit to heat the environment.

Also the more you leave the heater on, the more the thermostat switches (potential failure) and the more the element will corrode.

However if it's for convenience (I want my bath now!!) it's better to leave it on!

 

[2scoops0406]

I kinda knew this one was going to be a depends. The Eddie M house profile is thus.

2 Power showers in the morning one quick, one slow
at LEAST one full load of washing per day. (This only has a cold feed I think)
at LEAST one dishwasher load. (This only has a cold feed I think)

One bath for 3 kids per day.

So we use a lot of hot water, however I guess, and it is a guess, that it is more effective to just "top up" the cylinder temperature overnight than it is to let it cool down and reheat it when needed.

Sorry if I've opened a can of worms again, perhaps I should ask my mum

 

[kevplumb]

if the cylinder is well insulated it will cycle on the stat so its not running 24/7 anyway

 

[2scoops0406]

Hmm, I have a feeling I don't think I'll get a definitive answer. Oh b*llocks I'll just keep it on all the time !!

 

[ChrisR]

It's certainly cheaper to let it cool when it isn't needed. Money spent on pipe insulation in the airing cupd isn't wasted. My cyl is foam lagged but I have an extra jacket on it, and its v warm bewtween the two so the jacket is doing something.

As you have a Dw you knly need ater hot enough for a bath(45) so you could keep the temp quite low, which would reduce losses.
Shower is 38-40, washing-up without gloves would be 55 or so.

 

[2scoops0406]

It's certainly cheaper to let it cool when it isn't needed. Money spent on pipe insulation in the airing cupd isn't wasted. My cyl is foam lagged but I have an extra jacket on it, and its v warm bewtween the two so the jacket is doing something.

As you have a Dw you knly need ater hot enough for a bath(45) so you could keep the temp quite low, which would reduce losses.
Shower is 38-40, washing-up without gloves would be 55 or so.

Yeah, but primary losses into what, in my case the heart of the house.

 

[kevplumb]

you can afford it edward dear

 

[2scoops0406]

Don't call me dear

 

[kevplumb]

sorry m8 btw the sound card is rocking thanks for the link