hot water temp commercial kitchens.

[mm60103]

I'm at the receiving end of a whinge from the caterers that the hot water supplied to the sinks in the kitchen is not hot enough.

The water is supplied through an instanteous gas heater giving a 40 deg C lift i.e. with the incoming water at +5 deg C the water to the sink is 45 deg C.

I can't find any regulations / rules telling me what the temperature should be. I'm begining to think stored water at about 75 deg C is the answer.

Help???

 

[migoplumber]

in a commercial kitchen, stored hot water is the only way to obtain the required temperatures. you can get a required temperature limit from hse website. you will also find the required storage temperature depending on appliances, blending valves are generallt installed at pou.
possibly with a blender valve on cylinder outlet depending on design, a return circuit is normally required as minimum temperatures have to reach pou within certain times.

 

[mm60103]

Shaun

Thanks for the reply

I've had a look at the HSE website but no further forward. I can see that it legionella thrives between 20 - 45 deg C but this water isn't stored.

What I'm looking for is something like water must be at 60 deg C at the tap together with danger hot water notices. I've had a good look and still can't find those words or something like it.

Obviously with the present gas heater there is no recovery time.

cheers

 

[Renewable M]

the secondary return must deliver hot water to within 1.5m i think of the outlet?

we've been surveying a lot of schools (anyone looking for work in the hull area by the way?) and all of those returns are 50 ish at the cylinder. (leaving the cyl at nearer 60)

If you slow the flow rate, will you achieve a higher temp gain. slightly less gush, but maybe get it to more like 55deg.

45deg is toward the warm end of hand hot.

legionella regs do not apply to anything with a heat exchanger of less than 15l capacity.

 

[migoplumber]

renewable do the legionella regs not apply to all commercial instalations?

adding to above stored water in cylinder is circulated at 65 degrees, then at pou you are allowed to install blending valve (as said above within no less than than 1.5 metres of pou) and reduce the temp down to permitted levels. these vary i think from 38-46 degrees. cant remember!

 

[seangreen]

Any commercial property will have to apply to the current legislation regarding to the control of Legionnaires disease in hot and cold water systems. The current ACOP assists business and alike to comply with the minimum standards required. The document is produced by the HSE and is called the L8. It states in the document that the minimum stored temperature of a Calorifire is 60°C and if circulated should return to the Calorifier at no less than 50°C. The outlets from the Calorifier should be no less than 50°C and should reach this temperature within 1 minute of opening the outlet. There is no minimum size to the Calorifier, therefore if the Calorifire stores as little as 5 litres, the same rule will apply. Therefore if the water is not heated instantly i.e. a Combi, then the water needs to be stored at 60°C. If the outlet is in an uncontrolled area where people may be at risk of scalding then the outlet will need to be blended using a TMV set at 43°C to protect the end user. If the area is controlled, i.e. a kitchen then a warning label is sufficient. Any persons entering the kitchen must have to sign in and be inducted, where they are made aware of the temperature of the outlets may cause scalding.

 

[mm60103]

Shaun

Thanks for the information. This kitchen does not have stored water, no water tank, so L8 would not apply. The incoming mains water feeds directly to the instantaneous water heater. Incoming water temp is well below 20 degC - actually at 5 deg C when measured.

I'm still not able to find the minimum temperature that the hot water should be at.

Are there any regulations or is this a loop in the legislation and hot water is nothing more than a nice to have as long as it doesn't get too hot.

 

[fuzzy]

Shaun

Thanks for the information. This kitchen does not have stored water, no water tank, so L8 would not apply. The incoming mains water feeds directly to the instantaneous water heater. Incoming water temp is well below 20 degC - actually at 5 deg C when measured.

I'm still not able to find the minimum temperature that the hot water should be at.

Are there any regulations or is this a loop in the legislation and hot water is nothing more than a nice to have as long as it doesn't get too hot.

ill share what i know. stored water has to be at 65 degrees C. I worked on an old peoples home years back and on basins and baths the temps were reduced to about 36&41 respectively the kitchen sink was about 45 if i recall correctly.
A commercial kitchen i can see why they would want there to be a high temp output but i would like you prefer to know what temp that can be. I would presume it can be no higher than 65. in my experience of commercial kitchen is they have a direct heated unvented cylinder in the kitchen, then they can draw 65C at high pressure

not sure that helps you or not