How to size an accumulator ?

[john0740]

Anyone know how to determine the size of accumulator needed for a pressurised hot water system? Sizes I've seen seem to be 2, 5, 8 litres and upwards. How would I choose what size to fit to stop the water pump pulsing? Thanks.

 

[2Tizwoz]

Its a matter of balancing the cost and size of the accumulator against the frequency of the pump running partially and also to permit the water to expand as it is heated. The expansion will be related to the size of your cylinder so take that into account also.

 

[ccscott49]

get a big one if you dont want your pump cycling a lot, I have an 11 litre one, but what will limit you most, is the room you have for it.

 

[daveyw]

99p from your local minimarket. A 500ml Fanta bottle is what I use! I have two systems, a hot and a cold and each system has an upturned fanta bottle screwed into a tee. Total capacity of each system is about 4m of 15mm pipe to galley and heads. No pulsing. Had the same bottles in for the last 3 years, maybe it's time to invest in new bottles. Maybe coke this time!

 

[Anonymous]

Brilliant idea! Or, should I say, Fanta-stic! Thanks.

 

[ColinS]

No need to fit one with the new Jabsco pumps. I fitted a new pump this year, without an accumulator and there is no pulsing whatsoever. The accumulator I had was a PITA to fit and just added to the number of joints in the system. I'm pleased to be rid of it.