Sizing accumulators/large hot water demand

Joined
4 Aug 2008
Messages
48
Reaction score
1
Location
Bath
Country
United Kingdom
I need to size a system for my local rugby club which currently has 2, very ancient, 280 litre Andrews water heaters supplying 11 showers and 3 basins.

The most showers I've had to supply water for in the past is 5 so any advice would be welcome.

My first thoughts were to install an accumulator in conjunction with 2 x 300 litre Megaflows with a 28mm cold feed to the cylinder although the client has been told they would need three accumulators to provide adequate flow. I haven't fitted an accumulator before but thought this sounded a bit excessive?

Also, can I install 2 Megalfows in sequence or should they be fitted independently and then supply half the outlets each?

Cheers, Ben
 
Sponsored Links
Fit some Rinnai continuous water heaters, much less hassle and instant.
As far as accumulators go, double up the accumulators for the expected draw off. Speak to GAH to get info, but also get prices from Inta. Good luck
 
Or you can give guys at TWS a call, basically same as GAH - you tell em details - they tell you what you need...
 
To be honest an accumalator wont help you in this scenario,id say that the original installation was correct in supplying 2 andrews water heaters.

Personally i think 2 megaflows with independant cold mains and combined hot water output would be a mistake,more through reheat period than capacity.

if you want to go the megaflow route youll be looking at a 28mm outlet for your number of showers and basins would be correct based on LU's for industrial/commercial applicantions.

cold main in would be around 35-42 dependent upon other usage ie toilets etc,urinals are discounted.

Personal choice would be to spec either new andrews,ao smiths,lochinvar or rinnai water heaters.If you really must boost the water then a breaktank/boost set will be a beeter option than an accumalator which will only benefit during the high water point during the night not for all day showering.

Acc sizing is normally twice the size of any stored water ie 400litre acc for a 200 litre cylinder,soon becomes unrealistic to install.
 
Sponsored Links
Have just been looking on the Rinnai site which looks good although many options available. Based on what you guys are saying instantaneous water heating does seem the best option bearing in mind a bunch of sweaty rugby players will be using the majority of the hot water at weekends and then minimal usage in the week.

I'll give Rinnai a call in the morning to discuss the spec.

Regarding accumulators, I took a flow rate from a few outlets and it wasn't particularly good. Around 15L/Min, although they have been running 11 showers. Unless the hot water tap outlets I tested were restricted I would have expected a better flow to serve the outlets.

I've no experience with light commercial water heating systems and generally install system boilers/megaflows for the larger properties we work on. Am I missing something regarding water heaters such as Andrews regarding flow/pressure as lcgs mentions an accumulator won't help me?

Many thanks
 
You need to do some proper research/tests on the existing installation to work out how its operating.

One thing is certain, you dont run 11 showers from a 15 li/min supply unless they are VERY tiny rugby players who can shower in 1.1 li/min !

So far it seems you are rather out of your depth and I would recommend you team up with someone who has more experience. Perhaps John Cooke as he is also in Bath.

Tony
 
Spot on Tony, I am out of my depth hence the questions!

Its nice to learn new things though..

:)

I not so inexperienced to know that the flow rate I took isn't enough to supply the showers and should have spent more time testing the system. As there are no accumulators then I assume there are break tanks and a pump in the loft.

I made the mistake of doing a site visit on this job an hour before I was meant to whisk the missus away to London. Therefore, any of my oversights can be lumped on her...

Thanks for the recommendation of John Cooke, Tony. Is he contactable through diynot?
 
You should have took cummalative flow measurements by opening as many outlets as possible.

Would expect or you should envisage for the following to be applied, 4 lpm @ basin tap, 6lpm or 30lp use @ showers, 6lpm @ kitchen tap.

Rinnai are good but not cheap,consider the alternatives I mentioned,easiest option if all is working ok would be direct replacement of the Andrews.
 
I think John posts here as The Scruff or perhaps just Scruff so do a search and look in his profile. Or is that Doitall ?

Tony
 
Spot on Tony, I am out of my depth hence the questions!

Its nice to learn new things though..

:)

I not so inexperienced to know that the flow rate I took isn't enough to supply the showers and should have spent more time testing the system. As there are no accumulators then I assume there are break tanks and a pump in the loft.

I made the mistake of doing a site visit on this job an hour before I was meant to whisk the missus away to London. Therefore, any of my oversights can be lumped on her...

Thanks for the recommendation of John Cooke, Tony. Is he contactable through diynot?

The reason it has worked so well for so long is We probably installed it :rolleyes:

Avoid Accumulators. :rolleyes:

lcgs is on the ball take note of what he's saying.

The Rinnai is the modern Andrews without the stored water, and not necessarily better.

As it's not the Bath Rugby club, which one is it.
 
Its the Bathford rugby club Doitall. One of yours?

I've never fitted an Andrews or Rinnai or similar. Just standard vented/unvented and combis so appreciate the advice. Obviously I need to reassess the current installation but why is the use of accumulators not necessarily a first choice for some of you guys?
 
Acc's work in some instances,normally domestically rather than commercial with lots of out lets.

basiccally it works by capturing the pressure rise that occurs during low use periods(generally through the night),so before specing one you need to see what that increase is if any,no point fitting one if you dont have a rise.That rise is then put back into your system.

reasons for not fitting are

the rise in pressure could be minimal.
size is a big problem,you need twice the volume of your stored water content for any real use.
the pressure increase wont last long in a building where outlets are used frequently.

Ive only ever seen a couple of sports/leisure complexs with acc's,those visits were to specify removing them and installing booster sets.Nearly all have gas fired,stored water heaters for high recovery.

Lee
 
Its the Bathford rugby club Doitall. One of yours?

I've never fitted an Andrews or Rinnai or similar. Just standard vented/unvented and combis so appreciate the advice. Obviously I need to reassess the current installation but why is the use of accumulators not necessarily a first choice for some of you guys?

Know it well, "The Swan" used to be my local :D

The first thing you should be doing is checking the flow rate, pressure should be 3bar plus where it's situated.

What's wrong with using the Avon or are they getting soft now.
 
Whats the world become when even Rugby players are pampered prima donnas eh doitall?! Wanting a bloody shower after a match...Just an excuse to give each other a good lathering if you ask me.

Are you still installing in the Bath area doitall? They need this work doing before the new season starts and we may not be able to meet the deadline as we've just taken on a job in Bear Flat which will keep us busy for most of the summer.

I know he has had one chap give him a price who has quoted for the same sort of spec I originally had in mind before I started this post. Accumulators and unvented clearly would not be the ideal based on what has been discussed.

PS: Is the Swan worth a walk up the hill? The Crown's closed down!
 
Whats the world become when even Rugby players are pampered prima donnas eh doitall?! Wanting a bloody shower after a match...Just an excuse to give each other a good lathering if you ask me.

Are you still installing in the Bath area doitall? They need this work doing before the new season starts and we may not be able to meet the deadline as we've just taken on a job in Bear Flat which will keep us busy for most of the summer.

I know he has had one chap give him a price who has quoted for the same sort of spec I originally had in mind before I started this post. Accumulators and unvented clearly would not be the ideal based on what has been discussed.

PS: Is the Swan worth a walk up the hill? The Crown's closed down!

Bit posh and quite small, the Jollief on the box road is more lively :LOL:

I don't install anywhere nowadays. the joys of being retired. :cool:

3 Guys I used to work with maybe interested, if you want to peak in my profile and send the info I'll pass it on, and you can discuss it with them.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top