New system installation

[ali68]

Hello all just joined the forum and have done a lot of reading and picked up some good tips.

Now for my first post, I have just completed an extension to the house and one of the final jobs is to relocate the hot tank, its a conventional vented system and is too far away from the sinks etc and takes an age for hot water to reach the taps even with a booster pump fitted.

My only source of heating is electricity and I am on the total control total heating tarrif, which should simplify my options.

It has always been planned to locate the tank to the internal garage, so I am thinking a thermal store 210ltr and a 30tube 58mm panel array.

Does this sound over spec for the tank? reason I have went in this direction is I am in Orkney and dont see so much of the sun as we would like

Is a thermal store viable using immersion as the only form of boosting the heat, currently 0.07pence a unit?

Any other info you require please ask as I must admit I am a little lost as to waht diretion to go.

Many thanks for any replies.

[brackwell]

Ali,

You do not need a thermal store just because you want solar and indeed i would use your present tank - as indeed i do. 

The problem with hot water systems is that they are constantly loosing heat and it is much better that this heat is being used to heat your house ie the tank is within the insulated envelope of the house. To move it to a garage would not be a good idea.

What size are your water pipes if they are bigger than necessary then the pre run off will be more significant. 15mm is enough and perhaps you can shorten the run. I guess your already insulated like mad.

I do not like thermal stores because it is necessary to hold a larger volume of water at a higher temp and therefore more heat losses.   A 210L thermal store will only deliver a usable 120L of hot water - assuming it was fully hot in the first place.

A 120L vented tank which is what you perhaps have now can deliver nearly all 120L with water stored at a lower temp and lower surface area for heat loss.

With the immersion heater on a timer use it for the last 1/2 hr of the cheap rate so just before you need it.   If your day rate is the same 0.07p then you best option would be to use a inline heater which can be programmed with the temp required say 40C and this could be placed just before your sink etc thus eliminating the losses altogether. But because these only run off mains pressure you would need the thermal store if you had solar panels.
 This is a good use with solar panels as it does not matter what kind of day it is you are still getting max advantage and a guaranteed supply of hot water.

Ken

[ali68]

Cheers for your answer, try and answer some of your points..

Ali,

The problem with hot water systems is that they are constantly loosing heat and it is much better that this heat is being used to heat your house ie the tank is within the insulated envelope of the house. To move it to a garage would not be a good idea.

Understand what you are saying, was thinking about the in-house Newark cyl with extra insulation, heat loss would surely be minimal then, maybe not though!

What size are your water pipes if they are bigger than necessary then the pre run off will be more significant. 15mm is enough and perhaps you can shorten the run. I guess your already insulated like mad.

70/30 split between 22/15 respectively, no chance of shortening and yes plenty insulation

A 120L vented tank which is what you perhaps have now can deliver nearly all 120L with water stored at a lower temp and lower surface area for heat loss.

210 is what I have just now.

With the immersion heater on a timer use it for the last 1/2 hr of the cheap rate so just before you need it.   If your day rate is the same 0.07p then you best option would be to use a in-line heater which can be programmed with the temp required say 40C and this could be placed just before your sink etc thus eliminating the losses altogether. But because these only run off mains pressure you would need the thermal store if you had solar panels.
 This is a good use with solar panels as it does not matter what kind of day it is you are still getting max advantage and a guaranteed supply of hot water.

SWMBO loves her power shower and there is "no way in this world will it be going" so an in-line immersion wont really help me here.

Ken

Any other thoughts?

[ali68]

Oops that did not display as I was expecting , makes reading my reply a bit difficult..