Can anyone identify this hot water tank?

[ProDave]

On a job I am working on. This is the hot water tank used on conjunction with a wood pellet stove. The whole system is about to be ripped out and this tank may be going begging. I am trying to work out exactly what it is, and can I do anything useful with it.

 

First off, I cannot find a manufacturers name anywhere on it.

 

It measures 22" diameter and 65" tall

 

 

It is clearly unvented. Almost all of the ports are not labelled.

 

To the left connects the wood pellet Boiler. Just 2 pipes one top and one bottom go to the boiler and nowhere else.

 

At the back a top and bottom port connect to what I believe is the flow and return to the radiators (via a pump)

 

An additional top port connects to a 50L expansion vessel, an over pressure relief valve and a fill loop.

 

The only 2 ports that are labelled are "hot" and "cold" that appear to be fed with mains cold water and output via a thermal mixing valve.

 

 

I believe the black thing is a tiny expansion vessel? it has a Schroeder valve on the top.

 

The ONLY label on the tank is this one so I don't even know it's capacity

 

 

My thinking is it must be a thermal store (the hot / cold and blending valve looks like an output loop to me) or some kind of tank within a tank arrangement?

 

The thing that puzzles me is if it is a thermal store, then it's the first unvented thermal store I have ever seen.

[PeterW]

Looks like a McDonald Engineering TS. 

 

Black thing is an expansion to allow the coil water to expand. 

[ProDave]

So all the various top and bottom ports just connect to the store volume as simple as that?

 

There is also one immersion heater, and 2 thermostat pockets one near the bottom, one half way up.

 

Any idea from the size what volume it might be?

[Onoff]

Looking at the lip on the plastic top then Tempest (or maybeWorcester)?

 

 

 

[Nickfromwales]

Deffo a TS. Id say 300l at a guess, possibly 350l. 

[Declan52]

I have a 350l and that looks slightly smaller. Mine is 22 inches X 72 inches.

[ProDave]

If it were a  (Telford) Tempest the ports would be labelled and I am sure they would have their name on it

 

I can't see it is any use to me as a hot water tank as I really want an UVC not a thermal store (thermal store needs a hotter temperature to get a decent amount of hot water capacity so not really suitable)

 

I am wondering if it has a future as a heating buffer tank.  I had been planning an indirect tank for the heating buffer so I only have a small circuit filled with antifreeze circulating water from the heat pump to the cylinder(s)

 

Any thoughts on using this as a heating buffer and using a plate heat exchanger between the small heat pump circuit and the larger thermal store volume? I guess that would need a circulating pump on the thermal store side of the PHE?

[Tennentslager]

Good use you say

 

 coffin for a retired heating engineer for when the time comes...

They do them like that in Ghana if I recall...themed coffins like?

Be a good wake I'd bet ?

[Nickfromwales]

38 minutes ago, ProDave said:

Any thoughts on using this as a heating buffer and using a plate heat exchanger between the small heat pump circuit and the larger thermal store volume? I guess that would need a circulating pump on the thermal store side of the PHE?

You could cheat and send the heat back through the DHW coil thats already in it  It'll be a juicy coil so should work fine. 

[ProDave]

9 hours ago, Nickfromwales said:

You could cheat and send the heat back through the DHW coil thats already in it  It'll be a juicy coil so should work fine. 

But that would mean the entire thermal store would need to be filled with brine for the outside circuit to the heat pump.  My thought was a PHE on the input from the heat pump to the store so only a much smaller circuit needs to be brine and the store can just be standard inhibitor.  In this case just take from the tappings to feed the UFH and not use the DHW coil at all.

 

Or is that too much hassle?  Fill the tank and heat pump circuit with brine and use the DHW coil to extract heat to the UFH?

 

Assuming this tank is 250 or even 300L is that too big as a heating buffer tank?

[le-cerveau]

46 minutes ago, ProDave said:

But that would mean the entire thermal store would need to be filled with brine for the outside circuit to the heat pump.  My thought was a PHE on the input from the heat pump to the store so only a much smaller circuit needs to be brine and the store can just be standard inhibitor.  In this case just take from the tappings to feed the UFH and not use the DHW coil at all.

I think what nick means is use the DHW coil (Circuit) as the ASHP brine circuit (primary water) then just draw heat directly out of the tank.

[Nickfromwales]

35 minutes ago, ProDave said:

But that would mean the entire thermal store would need to be filled with brine for the outside circuit to the heat pump.  My thought was a PHE on the input from the heat pump to the store so only a much smaller circuit needs to be brine and the store can just be standard inhibitor.  In this case just take from the tappings to feed the UFH and not use the DHW coil at all.

 

Or is that too much hassle?  Fill the tank and heat pump circuit with brine and use the DHW coil to extract heat to the UFH?

 

Assuming this tank is 250 or even 300L is that too big as a heating buffer tank?

If it were me, and the tank IS going begging, then id use it as a buffer, fill it with brine, bite the bullet on the anti-freeze and ditch the PHE / pump / controls and the extra losses they'll generate, and use the buffer for DHW preheat. You'll be making most of your DHW at FAR higher CoP then, so a winner imo as DHW will be your biggest consumer of energy.

Factor in the PV and you've got a top notch solution there. Also, you'll need a much smaller UVC then too.  

If ever designing my own system, id go for a lot of low grade storage for DHW pre-heat, and prob feed a 6kw sunamp for the final 'lift' rather than an UVC.

 

1 minute ago, le-cerveau said:

I think what nick means is use the DHW coil (Circuit) as the ASHP brine circuit (primary water) then just draw heat directly out of the tank.

Yup

[Nickfromwales]

Actually, id suggest the above is a good candidate for a Sunamp Dual-port, for the higher grade DHW production, and leave the far cheaper lower grade heat in the TS provide much of the bathing temperature water. Only a small amount of 'boost' is needed to get kitchen / utility / hand wash temp water so I'd seriously consider putting money into that rather than into the UVC, even more so if the money for buying the buffer has been saved and the size of the boost device subsequently reduced by the size of the 'new' buffer

[ProDave]

5 hours ago, Nickfromwales said:

If it were me, and the tank IS going begging, then id use it as a buffer, fill it with brine, bite the bullet on the anti-freeze and ditch the PHE / pump / controls and the extra losses they'll generate, and use the buffer for DHW preheat. You'll be making most of your DHW at FAR higher CoP then, so a winner imo as DHW will be your biggest consumer of energy.

Factor in the PV and you've got a top notch solution there. Also, you'll need a much smaller UVC then too.  

If ever designing my own system, id go for a lot of low grade storage for DHW pre-heat, and prob feed a 6kw sunamp for the final 'lift' rather than an UVC.

 

Yup

I thought the DHW coil in a thermal store would be too near the top to use as a heat input coil?

 

This buffer tank is going in the plant room, as it's location is not sensitive for heating purposes.  Yes I could use the DHW coil as a pre heat to the real hot water tank, but that is going to be nearly 10 metres away, so for much of the hot water used the pre heat would not get to the tank in time.

 

I have finished that job now. I have made it known I am very interested in the tank, but the plumber has given him a price to "remove the old system and fit a new gas system" and he suspects the plumber has factored in some value from selling the cylinder and pellet boiler.  So it's now wait and see if I get it or not.

[Nickfromwales]

It fills a LOT of the inside of the TS. I used to think the same. 

I should add thats from the Telford ones ive bought with the 46kw 28mm coils. Of course we dont know with this one. 

[Nickfromwales]

5 minutes ago, ProDave said:

I thought the DHW coil in a thermal store would be too near the top to use as a heat input coil?

 

This buffer tank is going in the plant room, as it's location is not sensitive for heating purposes.  Yes I could use the DHW coil as a pre heat to the real hot water tank, but that is going to be nearly 10 metres away, so for much of the hot water used the pre heat would not get to the tank in time.

 

I have finished that job now. I have made it known I am very interested in the tank, but the plumber has given him a price to "remove the old system and fit a new gas system" and he suspects the plumber has factored in some value from selling the cylinder and pellet boiler.  So it's now wait and see if I get it or not.

Speak to the plumber and ask. If you dont you may miss it for a song if its not free. 

[ProDave]

6 minutes ago, Nickfromwales said:

Speak to the plumber and ask. If you dont you may miss it for a song if its not free. 

I intend to if I get the chance. Once the gas is connected I have to go back and earth bond that, so I am hoping I might meet the plumber then. It is not a plumber I know from other jobs.