Heat loss from pump to storage cylinder

[Nickfromwales]

  On 06/08/2020 at 16:26, ProDave said:

I wish fridges were sold like hifi

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Today could be your LUCKY DAY!!!!!!!!!

 

 

[SteamyTea]

  On 06/08/2020 at 20:55, Thedreamer said:

Hi @SteamyTea can you expand on the energy conservation part?

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Energy cannot be created, it can only change its form.

So if you suck energy from one place, to keep things in equilibrium, it has to be replaced.

So taking energy from the airing cupboard, just means that excess energy has to be put in there initially.  So you need to know where this energy comes from, in what quantities and is there a real benefit.

[Thedreamer]

  On 07/08/2020 at 13:05, SteamyTea said:

Energy cannot be created, it can only change its form.

So if you suck energy from one place, to keep things in equilibrium, it has to be replaced.

So taking energy from the airing cupboard, just means that excess energy has to be put in there initially.  So you need to know where this energy comes from, in what quantities and is there a real benefit.

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Yes, that is true but the heat taken is not really felt. All the heating since we have moved has come from our south facing glazing, from us and residual heat from appliances. If the bulk of the heat comes from the sun then this is free energy and it would less efficient to have a heat pump taking electricity from the cold outside. 

 

To me it’s irrelevant how efficient the system is as I could have had a large external heat pump that would be more expensive to run and require a lot of electricity.

 

This system is small in power but is easily meeting our demand for hot water for what seems to be very little electricity.

 

The cost was also very attractive at £2,500 for a good UK/Ireland constructed cylinder, mini heat pump, dual immersion (not planning to use!) and extraction system. 

 

As I said previously, I will reflect fully on how well it performs once a full year has passed but I don’t see how we could have got a cheaper method of hot water that provides so many functions.

 

[simon45089]

I am really interested in this thread as the issue faced by the op is exactly the same as my own. My wife is a very light sleeper and heat pump noise will not be tolerated . My own build is a barn conversion in a silent bit of countryside and locating the ASHP away from bedroom windows- which are situated on east and west walls, is not easy. 

 

I am really interested in the comment from nickfromwales regarding only using the ASHP to supply heating , and using a separate system for hot water. I was pondering if this was a good option, and I was considering using a small electric megaflo on night rate electric to  heat my hot water. This would allow me to turn off the heat pump in the summer months and keep things relatively simple when it was being used- I am not keen on constant tinkering with temperature etc. It sounds like another benefit is that by just using the pump to produce low temperature hot water there would not be a noise increase from boosting the temperature for hot bathing water every so often.

 

I am just learning about all this heat pump stuff,- largely from this fantastic forum, so please bear with me, but I would appreciate any views on my thoughts, and hopefully they will benefit the original poster. 

 

 

[SteamyTea]

  On 07/08/2020 at 22:33, Thedreamer said:

As I said previously, I will reflect fully on how well it performs once a full year has passed but I don’t see how we could have got a cheaper method of hot water that provides so many functions.

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It is always hard to compare, as you cannot easily build an identical house, subject it to the same weather regime and see what the difference is.  But you can run the DHW on pure electrical power for a few days and then look at the household data and see if there is an overall difference i.e. does the space heating requirements go up.

 

  On 08/08/2020 at 07:20, simon45089 said:

and I was considering using a small electric megaflo on night rate electric to  heat my hot water

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I can hear my water heating up at night, and that is the most basic of systems, just a 3 kW element in the bottom of the insulated cylinder.

[Thedreamer]

  On 08/08/2020 at 07:43, SteamyTea said:

It is always hard to compare, as you cannot easily build an identical house, subject it to the same weather regime and see what the difference is.  But you can run the DHW on pure electrical power for a few days and then look at the household data and see if there is an overall difference i.e. does the space heating requirements go up.

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Although it would be interesting to do so, it would not be possible. As the internal temperature would vary if it was a cloudy or a sunny day. If it gets to hot I tend to just open one or two of the windows depending on the wind direction to get the desired temperature. 

 

Another factor which I think make these air source heat pump efficient is that I am able to recover some heat from showers and baths into the system. Although the hot water for the shower just disappears (apart from steamy) into the treatment tank. When baths are used I tend to leave the hot water and this allows some of the heat to gets sucked back into the system and then this recovered heat can be stored for future use.

[SteamyTea]

  On 08/08/2020 at 09:04, Thedreamer said:

Although it would be interesting to do so, it would not be possible. As the internal temperature would vary if it was a cloudy or a sunny day.

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Just a matter of basic data collection and statistical analysis.

Bread and butter stuff.