Hot water question

[jon26]

Hi,

Will 2 x 300ltr Megaflos or ACV's cope with a 5 Bed B&B with 5 separate en-suites and large kitchen?

Any advice will be appreciated

 

[dcawkwell]

Go with the ACV they have fantastic reheat times. Only limited by how much heat from the boilers you can throw at it.

Is your water supply up to it?

 

[jon26]

Go with the ACV they have fantastic reheat times. Only limited by how much heat from the boilers you can throw at it.

Is your water supply up to it?

Thanks, I've seen the ACV's before, the tank-in-tank system is good.

Yes, I have a 1000 litre CW tank and twin pump set going in for the cold water, should be adequate.

 

[jon26]

Or alternatively a 600 litre ACV. Would this have a better performance than 2 x 300 litre cyls?

 

[dcawkwell]

Or alternatively a 600 litre ACV. Would this have a better performance than 2 x 300 litre cyls?

I would go for 2 rather than one big one. So in case of a failure you can take one out of service. You can also switch one off if your B&B isn't full.

Moving and installing a 600 litre would be a problem. Where 300 litre
is manageable.

 

[dcawkwell]

Assuming 10 people in the B&B each having 1 bath would require 50 litres of hot water each so approx 500 litres. Then the boilers would be reheating so I think 500 litres would be plenty so 2x 250 litres.
You also should have 2 boilers to work in cascade and act as a backup in case of failure of the either.

 

[Agile]

I would never fit a 250 li when a 300 li is more suitable.

No mention of the owner's hot water or for cooking and washing!

Tony

 

[dcawkwell]

I would never fit a 250 li when a 300 li is more suitable.

No mention of the owner's hot water or for cooking and washing!

Tony

The ACV cylinders reheat in minutes. Water storage isn't a problem.
Better to buy lots of kW to heat them as fast as needed.

 

[jon26]

Thanks for the comments. I agree with the advantages with 2 x smaller cylinders versus 1 x larger one. All noted.

As Tony mentioned, if I assume a reasonable amount of hot water for the kitchen operation then 2 x 300 litres may be more suited than 2 x 250.

 

[jon26]

Would you consider hot water priority?

I know the ACV cylinders can absorb a significant amount of kW's (the SL320 can in fact take 70kW). There is a 60kW boiler going in, but in the height of winter when supplying LTHW heating there wouldn't be a huge amount left for the cylinders, perhaps around 5-10kW (although that is not uncommon and may not be an issue).

 

[dcawkwell]

Would you consider hot water priority?

I know the ACV cylinders can absorb a significant amount of kW's (the SL320 can in fact take 70kW). There is a 60kW boiler going in, but in the height of winter when supplying LTHW heating there wouldn't be a huge amount left for the cylinders, perhaps around 5-10kW (although that is not uncommon and may not be an issue).

In a morning at peak time that is where the demand will be.
I would suggest maybe 2 smaller 30kw or 35kw boilers.
With the ACV cylinders being a tank in a tank there is very little resistance
so as soon as the zone valves open to the cylinders most of the flow is going to go through them until they are satisfied.