Help with Sizing a Tank Water Heater

[Muhammad Raza]

Hi,
We are trying to size a water heater with tank for a dormitory toilets, laundry and public showers. Kindly let me know what will be the best way to get about doing this? Following are the equipment that will be utilizing the water heaters,

Area Equipment QTY
Bar Kitchen Single Tap Sink 1
Bar counter Spray washer 2
Swimming Pool Toilets Washbasin 6
Showers 6
Salon Hair Wash 1
Normal Sink 1
Foot Spa 2
Dormitory Showers 10
Washbasin 12
Dormitory Kitchen Washbasin 2
Dishwasher 1
Dormitory Laundry Washer 4

Read more: https://www.diynot.com/diy/threads/help-with-sizing-a-tank-water-heater.487811/#ixzz4qljk9Bzk

 

[ShaunCorbs]

TBH you need the services of a commercial gas safe engy who holds the unvented qualification as well

 

[Muhammad Raza]

We are looking for an electric water heater, not gas.

 

[ShaunCorbs]

We are looking for an electric water heater, not gas.

Do you have 3 phase electrical ?

 

[Muhammad Raza]

Yes 480 3phase.

 

[ShaunCorbs]

Good

Have a word with a good spark to see what the limit load (max load) for the unvented cylinder

Do you know your incoming flow and pressure (mains cold water)

 

[Muhammad Raza]

Both the flowrate and pressures are adjustable as we have large water storage tanks which can provide water to the water heater through the water pumps.

 

[Muhammad Raza]

Backstory:
We have an existing electric water heater that is leaking and needs to be replaced. It is a 400 gallon tank heater with 90kw power. We think this is an overkill for the job. So we want to purchase a properly sized heater for the job.

 

[ShaunCorbs]

That's the set up I was looking for

Your looking 600 l min

Megaflow commercial you want re heat under an hour tbh

 

[ShaunCorbs]

Backstory:
We have an existing electric water heater that is leaking and needs to be replaced. It is a 400 gallon tank heater with 90kw power. We think this is an overkill for the job. So we want to purchase a properly sized heater for the job.

You sure that's not litres ?

As 900 gallon is over 4000 l

 

[Chuck]

Backstory:
We have an existing electric water heater that is leaking and needs to be replaced. It is a 400 gallon tank heater with 90kw power. We think this is an overkill for the job. So we want to purchase a properly sized heater for the job.

It's been sized to reheat in one hour or, equivalently, satisfy demand of up to 400 gallon/hour at 60°C.

If all ten showers are expected to be in use simultaneously at peak times it's probably about right. If the showers use 10 litre per minute each that's 100 litre / min of water at 40°C demand, say 60 litre / minute or 800 gallons/hour of HW.

Why do you think 90kW is 'overkill' ? It looks about right to me.