Variable flow Water Pump for instant water heater?

[DuckyUC]

I already get the system installed, and it work. It gives enough hot water. I only want to install a hot water pump to improve it, that simple. Why you guys seem anyone not using an unvent system are wrong? Instant hot water are so common in other country, whats the point of get an massive water tank that require more maintenance and more risk of leaking?

At the end of the post the ppl seem even made up an unvent system that only exist in imagination.
Hot water last for 2 hours and take 20min to recharge with amazing flow? If you can give me such a amazing model to me I will unstall my current system and install that unvent model.

Let say you have a 200L tank with all hot water heated up in E7 period, shower take 5L/min
200/5=40min shower

If each shower take 20min, that will be enough hot water for 2 shower.
For the 3rd person need a shower, he will need to wait the whole water tank boil to decent temp.

How long do he need to wait?
A immersion normally have 3kW output, 3000W/230V=13A (normally have 16A breaker in the fuse box)
My 12KW system can heat up 5L per min instantly
3/12=1/4, 5/4=1.25L per min
So 3kw should able to heat up 1.25L per min
200/1.25=160min=2hours40min.
With an immersion for the 3[SUP]rd[/SUP] person shower need to wait 20min (1[SUP]st[/SUP] and 2[SUP]nd[/SUP] shower run at same time)+2hour40min =3hours


With an instant heater the 3[SUP]rd[/SUP] person shower need to wait 20min(1[SUP]st[/SUP] shower) +20min (2[SUP]nd[/SUP] shower)=40mins


How come the unvert immersion becomes better?
Even with a 9kW output will still take 53min to heat the full tank of water
=53+20=1hour 13min waiting time

I would bet the fact is you take a 20min shower which use up half of the hot water, and the 20min recharge just heat up a bit the remain hot+ cold water mixture.
The point is if you do believe unvent system is the ultimate solution then give a physically exist model with spec rather keep saying how crap other system is.

 

[DuckyUC]

And my boiler room not even have space to put a 200L tank, I guess even I get an unvent only can have 150L max. Do you guys understand why I rather prefer get instant system at the cost of only 1 shower can run each time now?

 

[lame plumber]

la la la la la la lal la

 

[happyflyer]

Have you thought about this guys, this could be an old plumber playing mind games with use, dats what I fink, it's a wind up and you have all fallin into the trap, BTW did I reply to this post, my memory is going now, this chap needs a left handed fluffle valve, that will fixed or someone needs to block the thread with a Yorkshire 61.

 

[Howsie]

A shower does not use only hot water. As soon as the cylinder stat calls for heat the water is being heated. The recovery times mentioned are for a complete reheat not a top up.

Your understanding of the subject is poor that is why you are clinging onto a 5l shower rather than listening to the good advice from people who do this everyday.

Are you an engineer by chance?

 

[PlumbBobBob]

it is all getting very monotonous now imho

 

[lame plumber]

la diddly la la (change of tempo to improve the thread )

 

[Dotty]

la diddly la la (change of tempo to improve the thread )

Pom pom!

 

[DuckyUC]

my current system give 5L hot water @ 55C,
if the unvent system can mix cold water to increase the flow, so do I.
If the unvent give event less than 5L per min whats the point of geting an unvent?

 

[DuckyUC]

too many unvent fundamentalist!