Hot return circuit, how to control it.

[Russell griffiths]

Opinions please. 

 

Hope i set this up right, I’m a bit of a dumbo. 

Edited June 18, 2021 by Russell griffiths

[IanR]

I use Loxone to run it for a few minutes when someone enters a bathroom (and then again after 10 mins if they are still in there).

 

That doesn't include the Kitchen, otherwise it would be on most of the time, but we don't seem to notice when the Kitchen takes a little longer to warm up.

Edited June 18, 2021 by IanR

[PeterW]

Simple timer - runs 6am to 11pm, runs 1min/hour assuming it’s an insulated ring. 
 

You can use something like a 1CJDT0 with an asymmetric on/off driven by a really simple DIN timeswitch providing the supply to allow you not to run it 24/7 if you are really that bothered about not having hot water pumps running overnight 

[Bitpipe]

My spark used a combination of prox sensors in the bathrooms and detecting the light being switched on (something to do with the neturals) and used that to trigger both the hot return pump and the MVHR boost.

 

All I know is that it works a treat.

[Andrew]

I’ve installed one of these smart pumps - https://product-selection.grundfos.com/uk/products/comfort?tab=products. It’s meant to learn usage patterns and modulate accordingly.
 

 

We only moved in on Wednesday so can’t yet comment on effectiveness or energy usage. 

[Bitpipe]

1 hour ago, Andrew said:

I’ve installed one of these smart pumps - https://product-selection.grundfos.com/uk/products/comfort?tab=products. It’s meant to learn usage patterns and modulate accordingly.
 

 

We only moved in on Wednesday so can’t yet comment on effectiveness or energy usage. 

 

Have you not seen 2001? It will soon be singing nursery rhymes and locking you out of the house.

 

'Turn on the hot water Grundfos'.

 

'I'm afraid I can't do that Andrew'

[SteamyTea]

3 hours ago, Bitpipe said:

Have you not seen 2001

This will clear out your bowels and washing your hand will be the last thing on your mind.

 

[Russell griffiths]

Anybody else, 

[Oz07]

Is there a cost implication or negligible?

Which option is the simplest with least points of failure? Timer?

Edited June 20, 2021 by Oz07

[Oz07]

My alarm has just gone think it needs fuse would be wary of linking to temperamental alarm

[Russell griffiths]

The electrician thinks the cost of running it most of the time will be cheap, but he likes spending my money!!!!

im afraid if we don’t have measures in place to limit electricity usage then we might have some unhappiness when we get our first bills. 

He thinks I’m like a walking cashpoint. 

Little does he know that I live on beans on toast all week just so I can afford another roll of cable. 

[SteamyTea]

Just now, Russell griffiths said:

Little does he know that I live on beans on toast all week just so I can afford another roll of cable. 

Is cable that cheap?

[Russell griffiths]

Just now, SteamyTea said:

Is cable that cheap?

Some days I just have the toast and no beans ??. 

[Oz07]

A minute every 15 sounds good. Presumably you could turn off at night or adjust timer to suit as you get a feel for it

[Temp]

Another way is to put a pipe stat on the return so the pump runs until water returning to the tank is hot. Then it stops until the pipe cools down. 

[Nickfromwales]

4 hours ago, Russell griffiths said:

The electrician thinks the cost of running it most of the time will be cheap

Running the HRC pump is pennies. Less P/A than feeding, say, a lake full of carp for example.

Providing the hot water to send around the pipes; "free" when the PV is on and burning, cheap enough also when the ASHP has to reheat it, eg during winter etc, especially when you can get electricity as cheap as 5-6p/kWh and strategize when you heat the water fully ( eg at night on Octopus Go! ) and THEN put that through an ASHP and possibly halve that again to 3p/kWh. Can't please everyone eh? ?‍♂️

People cry about spending pennies, by comparison, after saving a LOT of money doing as much of the work themselves as they could / can. Some are more skilled / adept than others so save much more than most, and those folk need not sit around weeping about parting with a hundred or so bucks a year ( IMHO ). They probably spend more money a year, say, on throwing expensive crockery about........but that's just a wild guess of course .

This is a bit like fitting lots of lights in your house, and then moaning about how much electricity it costs to switch them on. 

A bit like why most never own an american V8 gas-guzzler, but instead go get a Prius and drive it downhill only, only on windy days, with only if the wind is behind it....? , probably.

On a serious note;

A cheaper way of getting hot water to the most remote parts of the property would probably be to run a 1000m long hose pipe through the local village, with a sign attached to it saying "rub this pipe for luck" and then use the heat energy from the friction to offset the £100 a year costs of running the HRC.

You know what, that's a Dragon's Den opportunity if I've ever heard one. Nobody nick that idea until I get back, ok.  I mean it!! 

 

[Russell griffiths]

@Nickfromwales made me spill my tea mate ??

 

it was only a cheap cup, you need to let this go. 

 

[Nickfromwales]

8 minutes ago, Russell griffiths said:

@Nickfromwales made me spill my tea mate ??

 

it was only a cheap cup, you need to let this go. 

 

Still in trauma therapy chief…….?

[Dan F]

On 20/06/2021 at 14:27, Russell griffiths said:

The electrician thinks the cost of running it most of the time will be cheap, but he likes spending my money!!!!

 

Pump will consume next to nothing.  The issue with it running it all day is that you get heat-loss (how much depends on how well insulated HRC is):

- This costs energy/money.

- In the summer this can contirbute to over-heating.

On the flip-side, if you don't run the pump enough, then you'll waste water wating for the hot-water to come out of the tap.

 

We've tried to avoid HRC by using 10mm pipe.  For the a couple of remote basins that may require HRC, the plan is to use Loxone which will allow me to run a pump based on time of day and/or presence.

 

[PeterW]

On 20/06/2021 at 19:03, Nickfromwales said:

Running the HRC pump is pennies. Less P/A than feeding, say, a lake full of carp for example.

we worked out the additional cost over a year including the cost of running the ASHP to replenish 400 litres on a 24/7 pump was about £85… used a £20 timer with 15min/hr from 6am-11pm and so it paid for itself in 3 months. That was a commercial building with intermittent usage during the week. 
 

£85 buys a lot of pies … 

[Nickfromwales]

Hmmmmm ?

 

Pies…..or Daddy?
Pies…..or Daddy?

 

Pies it is. @Russell griffiths can wash his hands in cold water. 

 

11 hours ago, Dan F said:

(how much depends on how well insulated HRC is):

15mm hot and 10mm HRC are both inside the same piece of ( 22mm dia x 25mm wall ) Climaflex from start to finish.