Stainless buffer advice

[chrisb]

Has anyone used one of these https://www.ebay.co.uk/itm/BUFFER-TANK-HEAT-PUMP-CE-B60/112659997759 in their installation?

 

I want to use a buffer in my house which has a mix of rads, UFH and DHW by UVC. Boiler is a heat-only type, hence the buffer.

I have enough expansion volume separately, so not really bothered about the integrated expansion option in the product above, but I think it would be daft to overlook the option of having an immersion available incase either the boiler breaks, or in the future when I have PV, I can dump it there.

 

£316 delivered seems a reasonable price?

 

Thanks

Chris

[PeterW]

Bit that always worried me about these ones was the “innovative design” which means there are compartments inside it which could lead to airlocks. 

 

ESP do one which is just a big tank I think - I’ve used a copper cylinder which isn’t designed for high pressure so run everything at 1 bar which is perfectly adequate. 

[PeterW]

@chrisb this is the one I was thinking about. 

 

Buffer

[Nickfromwales]

9 hours ago, PeterW said:

@chrisb this is the one I was thinking about. 

 

Buffer

Strange a stainless buffer has a Magnesium ( sacrificial ) anode pocket? Knee-jerk from the manufacturer and just left blanked off ?

 

20 hours ago, chrisb said:

Has anyone used one of these https://www.ebay.co.uk/itm/BUFFER-TANK-HEAT-PUMP-CE-B60/112659997759 in their installation?

 

I want to use a buffer in my house which has a mix of rads, UFH and DHW by UVC. Boiler is a heat-only type, hence the buffer.

I have enough expansion volume separately, so not really bothered about the integrated expansion option in the product above, but I think it would be daft to overlook the option of having an immersion available incase either the boiler breaks, or in the future when I have PV, I can dump it there.

 

£316 delivered seems a reasonable price?

 

Thanks

Chris

Just had a look and IMO not a bad little cylinder. The 'baffle' arrangement that some "innovative" cylinders manufacturers fit inside is what has got @PeterW spooked, but in this instance they are just referring to the cylinder being what we guys call a 'bubble-top' tank. The vent at the top gets blanked off to capture air in the upper section of the vessel, and the volume is dictated by the next lowest tapping where any excess air ( beyond the stated 15L ) gets to escape and be vented by a bottle vent. Downside is, a bubble-top often needs emptying and refilling to reset the trapped expansion air volume so I routinely avoid that arrangement.

If you check with this seller, you should find you can fit an automatic air vent to the top of the cylinder and fill it entirely to 60L volume and fit an external dedicated expansion vessel. Thats what I would do. 

You'll be fine with this cylinder  and id go for the bigger volume as 50L ( and 60L tbh ) is borderline. Personally I'd go for at least 90 L due to the mix of heat emitters, 120 L would be better suited.

Try and locate the buffer where it can be useful wasted heat eg the airing cupboard.   

 

Have you not considered a TS to do both buffer and DHW ( via an instantaneous internal hot water coil ) ?

[chrisb]

Lack of internets got in the way of replying - sorry. Wet trees are an issue if you have a wireless bridge providing your internet connection ?

 

I've got an expansion vessel in the circuit anyway as I'm going for sealed rather than vented, so I wan't thinking I'd need another one?

 

I was thinking about 120L originally, but space, cost and heat loss is a concern. The boiler, UVC and buffer will all be in the attached garage, which is underneath two bedrooms, but not the biggest space (16'x7'). I'm expecting to put decent non-leaky doors on it and treat it as a room, but with the UVC and buffer it will get hot. MVHR will take care of some of the heat, but I would like to keep waste heat to a minimum in there. 

 

That was the main reason for the UVC/Buffer option as when the heating is not required the buffer can be cold, and the UVC can be heated to a lower temp than a TS. Radiators-wise, we have never really struggled for heat in any of the rooms, and often have them switched off.

 

I'm expecting the floor to run at no more than 25 degrees maximum (that was plenty last winter when we still had draughts and the floor could only get that hot with the 3kW Willis heater. It's pipes-in-slab at 150mm spacing, so once it's warm, it takes a very long time to cool down.

[chrisb]

Is there anything to stop me using a small direct (or indirect, and not use the coil)  UVC instead of a purpose-made buffer?

[PeterW]

indirect will reduce the amount of antifreeze needed in any UFH / ASHP circuits. I've fitted a 70 litre direct copper cylinder as a buffer.

[chrisb]

I hadn't thought about ASHP - we have mains gas, so I was only considering that and potentially PV in the future.

I was expecting to run the UFH loops with regular CH inhibitor in them - is there anything wrong with doing this?

I did like the idea of a coil in the buffer incase I wanted to connect another heat source of some kind in the future, but didn't plan on using it for now.