Hotel plumbing design

[kasser]

Out of curiosity, how are hot and cold water systems designed for places like a hotel or gym with multiple bathrooms? I always find these places have water gushing out of taps and you never have to wait for hot water.

My guess is hot and cold water tanks with pumps and secondary circulation for hot water. Any special pump?

 

[Stigster]

Yes, they use secondary return loop with a pump as you assumed. The pump must be suitable for continuously replenishing supply which usually means fitting a bronze pump. Using a bronze pump is extremely important.

The most damage I ever saw done to a property was from a secondary return using a standard central heating circulating pump. Whilst the owners were on holiday for a fortnight, the head of the pump corroded to the point it simply fell off allowing the 22mm mains feed to flood the house whilst they were away. It was in the loft of a 2 story property full of Persian carpets and artworks. A total disaster.

 

[centralheatking]

Out of curiosity, how are hot and cold water systems designed for places like a hotel or gym with multiple bathrooms? I always find these places have water gushing out of taps and you never have to wait for hot water.

My guess is hot and cold water tanks with pumps and secondary circulation for hot water. Any special pump?

We used to look after Hotels in Bath..up to 50 rooms or so. Basically there will be 3 boilers
big gas types. One for heating one for hot water and one spare. In the same way as the heating circuit, the domestic hot water is produced and continuously circulated around a 2 inch maybe 3 inch continuous circuit. The take offs for the ensuites are twigs off the circuit but are as short as possible to get instant hot water. Some of these boiler rooms were a thing to behold. centralheatking

 

[kasser]

I suppose the pumps are such that they can run 24-hours a day? Is there more than one per hot/cold water as backup perhaps? Are they activated when they sense demand, i.e pressure drop?

 

[centralheatking]

I suppose the pumps are such that they can run 24-hours a day? Is there more than one per hot/cold water as backup perhaps? Are they activated when they sense demand, i.e pressure drop?

Yes there were two per circuit and they ran 24 hrs per day and were water cooled, some were turney turbines which ran a sep. impellor.
The boilers all had lead string which held the gas gate valves open so if there was a fire the lead melted and the gate dropped unless you stepped on one. centralheatking

 

[Last Plumber]

Out of curiosity, how are hot and cold water systems designed for places like a hotel or gym with multiple bathrooms? I always find these places have water gushing out of taps and you never have to wait for hot water.

My guess is hot and cold water tanks with pumps and secondary circulation for hot water. Any special pump?

It varies from place to place. They do all tend to have pumped secondary circuits. Most that I have worked in will have direct fired hot water boilers. Some are tank fed, some are pumped like you might see on a ship or in a launderette. Pipe size is obviously very important.
Are you planning a hotel job?

 

[Stigster]

I suppose the pumps are such that they can run 24-hours a day? Is there more than one per hot/cold water as backup perhaps? Are they activated when they sense demand, i.e pressure drop?

In a domestic setting the secondary return pump would either be on a timer for running it during expected hours of demand, or with an infra-red sensor in the bathroom so that when you enter it switches the circulating pump on and by the time you have finished your business, the hot water is where you need it.

In a hotel setting it is more likely that it will run 24/7/365 as demand could be at any time of day.

In commercial applications most systems are set up for redundancy with a second pump as a backup. Some systems will have the option to switch between the two at regular intervals to prevent stagnation and seizing of pumps.

 

[Marka1411]

Just come across this thread, i used to do a lot of commercial work.

Big secondary returns installed as already said, also sometimes 3-4 cylinders linked up with plate heat exchangers for faster recovery. Interesting work and very well thought out and planned. Depending on the building and usage but would sometimes have boosted tanked cold water as the main wouldn't be able to cope with the demand.

Miss that sort of work.