Patrick

A puzzle for the plumbers on here . permanent hot water supply . how to use it

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I have a bit of a task here .

How would you go about plugging a permanent hot water reservoir into the house (ufh and DHW)

If got a tank of (very) hot water .

It s a 2000l reservoir that is used for server water cooling (to minimize run-to-waste water cooling) .

I would like to use the hot water from there to heat

A. The hot water cylinder

B. Under floor heating .

 

How could this setup look like

As far as I understand , usually the hot water at the house works in the way that you heat up water when water is needed and not keep it permanently on max temperature (can't do this with ufh anyways)

So would probably need 2 separate cycles

Cycle 1 is for cooling the servers and is permanently on hot temperature

Cycle 2 is the water cycle in the house for heating UFH and hot water tank.

If cycle 2 "needs" hot water , switch switches water from cycle 1 into cycle 2 ....

 

Excuse my stupid explanation . I m missing terminology and knowledge here.

 

So please, let me know how I could start building this as an experiment to test out.

 

 

Edited by Patrick

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How much power does the server consume from the mains and what percentage do you think is captured by the cooling system? 

 

Where does the server currently send the heat? Air cooled rad? 

 

What's the max temperature you can allow  the cooling water to get to before the server get too hot?

 

I'm away tomorrow but others may ask same questions.

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Just circulate this spare hot water through a heat input coil to a DHW tank or thermal store.

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1 hour ago, Temp said:

How much power does the server consume from the mains and what percentage do you think is captured by the cooling system? 

 

Where does the server currently send the heat? Air cooled rad? 

 

What's the max temperature you can allow  the cooling water to get to before the server get too hot?

 

I'm away tomorrow but others may ask same questions.

Consumption Is 7kw with 40% going into heat. So heating is approx 2.8kw . 24/7 . Currently water cooled but run to waste so pretty wasteful . Have a tank that minimises the run to waste but still ..

Temp of the water is 74degrees max, so plenty of reserve .

Thanks . Theses are good questions.

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1 hour ago, ProDave said:

Just circulate this spare hot water through a heat input coil to a DHW tank or thermal store.

Yes. That principle is somewhat clear to me. But bear in mind i'm not a plumber:

 How do you switch it "off" when the DHW tank becomes too hot . You have to switch the circle ...

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2 minutes ago, Patrick said:

Yes. That principle is somewhat clear to me. But bear in mind i'm not a plumber:

 How do you switch it "off" when the DHW tank becomes too hot . You have to switch the circle ...

With a normal heat source you would turn the heat source off.

 

Assuming you can't do that then instead you have to divert it to a dump load which could be a radiator outside or something similar.

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17 minutes ago, ProDave said:

With a normal heat source you would turn the heat source off.

 

Assuming you can't do that then instead you have to divert it to a dump load which could be a radiator outside or something similar.

Yes. That s perfect. Stupid question: is there an automated valve the rediverts the flow of water at certain temperature.. Or how would that technically look like ... I 100%agree to the idea

Edited by Patrick

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3 port 2 position valve (not mid position) controlled by the cylinder thermostat.

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21 minutes ago, ProDave said:

3 port 2 position valve (not mid position) controlled by the cylinder thermostat.

Brilliant 🤝

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Surely it's simpler than this- I've looked into this on a commercial scale but it never made sense. If you have the HW 'for free' already then the coil through a thermal store makes a lot of sense.

Just have a 2 port valve and pump that cicrculate water from the 2000L reservoir through your HW cyclinder/ thermal store coil. When your cylinder/ thermal store is satisfied, close the 2port valve and turn off pump. Then the 2000l reservoir continues on it's current merry cycle exactly as is? No need to introduce an additional radiator dump unless your reservoir is currently overheating? It must be dumping the heat somewhere (air cooled rad as above?) so can continue to do that once you've had your take off it?

 

Take you UFH/ heating from the thermal store tappings and the DHW from a plate heat or a second internal coil in the TS?

Edited by Wil
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Could you use the 'spare' hot water on a recirculating DHW system.  That can also act as a cooling circuit.

I wish I had spare energy, maybe I need to run a very large TOR relay at home, then host dark web content, that should pay the bills.

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How much power does the house need? I think it will be easy if the server  can provide it all. Bit harder, but not much, if you need a boiler or similar as well.

 

 

 

 

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6 hours ago, Wil said:

Surely it's simpler than this- I've looked into this on a commercial scale but it never made sense. If you have the HW 'for free' already then the coil through a thermal store makes a lot of sense.

Just have a 2 port valve and pump that cicrculate water from the 2000L reservoir through your HW cyclinder/ thermal store coil. When your cylinder/ thermal store is satisfied, close the 2port valve and turn off pump. Then the 2000l reservoir continues on it's current merry cycle exactly as is? No need to introduce an additional radiator dump unless your reservoir is currently overheating? It must be dumping the heat somewhere (air cooled rad as above?) so can continue to do that once you've had your take off it?

 

Take you UFH/ heating from the thermal store tappings and the DHW from a plate heat or a second internal coil in the TS?

Exactly like this. That's what I imagined. Just that the 2port valve needs to open/close automatically... What kind of valve would do this (very silly question. But I'm not a plumber)

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1 hour ago, Temp said:

How much power does the house need? I think it will be easy if the server  can provide it all. Bit harder, but not much, if you need a boiler or similar as well.

 

 

 

 

No . There would be no need for separate source of hot water. Problem is more that the water will be too hot . House is passiv so not that much needed and input is permanent 70degrees hot water ...

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14 hours ago, Patrick said:

Exactly like this. That's what I imagined. Just that the 2port valve needs to open/close automatically... What kind of valve would do this (very silly question. But I'm not a plumber)

 

A tank stat on your thermal store (close to the bottom so you're constantly topping up given it's 'free') could call for heat, the two port valve would open, when opened, it's limit switch would turn the pump on and your domestic cylinder would top up.

 

You could make it even simpler and run your TS permanently- forget the valve and treat it as a heat sink from the 2000l store. put the TS in series with your dump load, so all heat runs through the TS on it's way to being dumped. You'd need some isolation valves for maintenance and need a bypass for when the cylinder was 'at temp' although it will never go above 70 if  the temp of the water leaving the 2000l is 74.

 

Effectively you're just treating your 2000l as a boiler which runs at a constant 74 and need a plumber to sort you out a thermal store that can use it. Depending on how hard you use DHW/ heating (you say little above) then the 2.8kW 'recovery' of the main tank shouldn't be an issue. 

 

 

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You could plumb in a plate heat exchanger, say a 50 kW one,  Then run whatever you want off of that.  No ned for an extra storage cylinder.

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8 hours ago, SteamyTea said:

You could plumb in a plate heat exchanger, say a 50 kW one,  Then run whatever you want off of that.  No ned for an extra storage cylinder.

True . But I like to keep the house system as "regular" as possible as you never know what's gonna happen and I might decide to take the hot water source elsewhere ... Then It's better to have a functional system in place. 

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