Which cylinder - standard or ACV?

[bobby62]

What would provide more hot water a 500 litre standard coil cylinder, or a 400 litre ACV tank-in-tank cylinder. It is for a large house (linked to my earlier 50kW output boiler post). The property has six separate bathrooms with all the usual draw off demands.

I know the ACV would perhaps be more responsive in terms of reheat but the larger capacity cylinder may be the better option. Has anyone got any recommendations from previous installations?

I don't think the ACV 400 comes with an immersion either?

Thanks

 

[Dan Robinson]

Depends on how you control it.

 

[bobby62]

Depends on how you control it.

7-day 24-hour programmer on boiler circ - no hot water priority

 

[Dan Robinson]

7-day 24-hour programmer

hhmmm....

 

[Dan Robinson]

You seem to have some entrenched views that could be detrimental to the effectiveness of your potential system.

 

[bobby62]

You seem to have some entrenched views that could be detrimental to the effectiveness of your potential system.

Thanks Dan, are you suggesting hot water priority?

 

[Biggles..]

One will provide 100 litres more than the other.

Coil size of a normal cylinder likely to be 20kw, heat requirement of an ACV likely to be 40-60kw.

Neither the correct solution for 6bathrooms with rain heads.

 

[dcawkwell]

The ACV as you can reheat it faster.

If demand is very large you might need to think of more than one cylinder and an accumulator tank.

 

[dcawkwell]

One will provide 100 litres more than the other.

Coil size of a normal cylinder likely to be 20kw, heat requirement of an ACV likely to be 40-60kw.

Neither the correct solution for 6bathrooms with rain heads.

What would the correct solution be for 6 bathrooms with rain heads?

 

[Biggles..]

Would depend on how they are used, together/Seperate, flow rates etc.

 

[bobby62]

One will provide 100 litres more than the other.

Coil size of a normal cylinder likely to be 20kw, heat requirement of an ACV likely to be 40-60kw.

Neither the correct solution for 6bathrooms with rain heads.

These companies manufacture large capacity cylinders for a reason, I don't see why this is not a suitable system for the property. In the context of capacities available a 400 or 500 litre cylinder is small, you can get 1000 - 2000 litres models if you require them.

2 x accumulator stores will also be installed to provide a better flow rate.

There are a couple of 300mm dia shower heads and a number of 200mm shower heads (no body showers etc.)

 

[bobby62]

Would depend on how they are used, together/Seperate, flow rates etc.

The $64,000 dollar question! I know flow rates but who can actually say exactly how often, when and for how long they will be used??

 

[Biggles..]

Your the client surely you know how likely 6 showers will be ran together or how likely someone will fill 6 baths conseqatively.

 

[bobby62]

Your the client surely you know how likely 6 showers will be ran together or how likely someone will fill 6 baths conseqatively.

I would say 4 may be likely to be run together (for how long - who knows). It comes down to how people use the showers and how long they intend to stand under it 5 mins, 8 mins, 12 mins ?? I appreciate it is unlikely 6 showers would be running at the same time and there has to be an element of diversity

 

[Biggles..]

No space for 2 boilers but room for 3 cylinders totalling 1100 litres.

To me your mind is made up, you have the chance of running 120lpm if all showers are used.( that's quite small for a rainhead)
80/40 so 5 or 6 mins of showering then a full recovery.