Air source heat pump - Grant

Spoonie_Turtle

Reed_Richards said:

Spoonie_Turtle said:

 BUT with solar panels you can run it for free when they are generating.

Not necessarily free.  It depends on how the maximum/typical output of the solar panels is by comparison to the (maximum) power your heat pump requires to heat your hot water.  In my case my solar panels (4.8 kW peak) cannot provide enough power on their own as my heat pump takes 6 kW peak when heating the hot water.

Good point, have amended my post to be more accurate.

Reed_Richards

matelodave said:

Its still got to be cheaper to run it during the day when the sun is shining than overnight unless you've got a really low off-peak tariff

I've had an Efergy energy monitor on my 11kw Daikin and I've never seen it peak above 4kw even when its running flat out.

 A lot will depend on how its controlled, mine is inverter driven and so has a slow startup. If you stand close you can hear the motor and the fans slowly wind up to maximum

I guess that some heatpumps may have capacitor start motors which could take a high inrush current as the compressor or fans start but I shouldn't think that there are many nowadays

My heat pump is nominally 12 kW, is inverter-driven and has a slow start-up but it still peaks at around 6 kW when heating the hot water to 50 C.  If it used less peak power it would get the water to temperature more slowly.  This wouldn't matter at all in summer but in winter would mean that there is a longer pause without the heating running as heat pumps supply either the hot water cylinder or the central heating but not both at the same time.  

FreeBear

shinytop said: Using a kettle for washing up/hand washing is a daft idea.  If you boil a kettle every time you wash up, go to the loo, before you eat or cook, after you've dug the garden, etc., it will cost more than pennies and also be a right pain.

To kill bacteria/viruses quickly needs a water temperature of 60°C or higher - This will scald, so do not try.

Washing your hands with soap and cold water is just as effective in removing germs. No need for hot or even warm water. Save the kettle of boiling water for the washing up.

https://www.bbc.co.uk/news/health-40118539

https://www.cdc.gov/handwashing/faqs.html#water-and-handwashing

Spoonie_Turtle

FreeBear said:

shinytop said: Using a kettle for washing up/hand washing is a daft idea.  If you boil a kettle every time you wash up, go to the loo, before you eat or cook, after you've dug the garden, etc., it will cost more than pennies and also be a right pain.

To kill bacteria/viruses quickly needs a water temperature of 60°C or higher - This will scald, so do not try.

Washing your hands with soap and cold water is just as effective in removing germs. No need for hot or even warm water. Save the kettle of boiling water for the washing up.

https://www.bbc.co.uk/news/health-40118539

https://www.cdc.gov/handwashing/faqs.html#water-and-handwashing

Only trouble is when cold water hurts your hands (and teeth, when brushing!  No I don't rinse but I do wet the brush and it hurts if it's cold).  The cost of heating water to a comfortable temperature is, to me, worth it.

shinytop

Spoonie_Turtle said:

FreeBear said:

shinytop said: Using a kettle for washing up/hand washing is a daft idea.  If you boil a kettle every time you wash up, go to the loo, before you eat or cook, after you've dug the garden, etc., it will cost more than pennies and also be a right pain.

To kill bacteria/viruses quickly needs a water temperature of 60°C or higher - This will scald, so do not try.

Washing your hands with soap and cold water is just as effective in removing germs. No need for hot or even warm water. Save the kettle of boiling water for the washing up.

https://www.bbc.co.uk/news/health-40118539

https://www.cdc.gov/handwashing/faqs.html#water-and-handwashing

Only trouble is when cold water hurts your hands (and teeth, when brushing!  No I don't rinse but I do wet the brush and it hurts if it's cold).  The cost of heating water to a comfortable temperature is, to me, worth it.

As well as being more comfortable for some people, hot/warm water will remove dirt, sweat, oily substances, etc. more effectively and quicker than cold water, even if soap is used. 

Having said that, by the time my hot tap gets hot I've normally finished so I mostly just use cold.