Qty of showers, cookers and hobs in a 6 bed HMO.

[Jasonss]

Just a few questions about the setup for a 3 storey, 6 bedrooms HMO (house of multiple occupancy).
This is a domestic house with 6 bedrooms but each bedroom is let individually to unrelated tenants, rather than to 1 family.

The gas and electric bills are paid for by the landlord, not the tenants.

Property:
3 storeys.
6x bedrooms.
5x Ensuite/bathrooms including 5x showers.
Interlinked smoke alarms in all bedrooms, landings and lounge.
Heat alarm in the kitchen and cellar.
2x ovens.
2x hobs.
Possibly immersion heater (depends on heating system).

2nd floor has 3x bedrooms and 3x ensuites.
1st floor has 3x bedrooms and 1x ensuite.
Ground floor has living room, kitchen/diner, bathroom.
Cellar is not used but will probably house the heating system.


Circuits to be as follows:
2nd floor sockets.
2nd floor lights
1st floor sockets
1st floor lights
Ground floor sockets.
Ground floor lights.
Kitchen Sockets
Kitchen Lights
Smoke alarms
Electric shower(s) ? Maybe.
Electric cooker circuit(s) ? Maybe. 2x 6mm cable - one for each cooker circuit.

2x single electric fan ovens will be installed. These can be connected to a standard 13a fused spur on the kitchen circuit.
The will be an option to have 2x electric ceramic hobs and so 2x 6mm cables will be run in for these.

Questions:
1.
If 2x ceramic hobs of 6kw each are installed, how many 8.5kw or 9.5kw showers could be installed?

2.
If instead of the electric hobs, gas ones are used, how many 8.5kw or 9.5kw showers could be installed?


It comes down to a trade off with the boiler and heating system needed to be able to feed 5x showers (non electric), or if a cheaper system can be installed if it only has to feed 2 or 3 showers (with the others being electric).

 

[OwainDIYer]

It depends on the oven ratings whether they can be connected through 13A spurs off a socket circuit. A lot are intended for continental Europe where 16A circuits are common, and would need to be connected to a cooker circuit. I would NOT have two ovens on a socket circuit even if they are less than 13A each. Apart from loading, if an element fails and knocks off the circuit that is all kitchen socket power lost.

Freestanding cookers are cheaper than built in appliances and quicker to pull out and replace when needed.

You have not mentioned laundry appliances.

The maximum load possible depends on your service intake rating, which you haven't mentioned.

Gas hot water is about 1/3rd the cost of electric showers. Five showers (with water restrictors / low flow heads) should be manageable by a decent sized cylinder system, but if you want unvented you rely on your incoming mains pressure and flow.

 

[chivers67]

My first thoughts are supply - is it single phase or three phase?

 

[Jasonss]

thanks for the reply

its a 100a supply
there will be a washing machine. probably not a tumble dryer because its not required to have one in the property.


freestanding cookers might be a good option. this would either be both electric, or 1x electric and 1x gas. i know it makes more sense to have 1x of each however i would prefer to have both electric.

the single fan ovens i was looking at from both Lamona and CDA can both only require hard wiring into a 13a fused spur. a separate radial 2.5mm circuit could be run for each of these. their manual states this : This appliance must be connected by a competent person, using fixed wiring via a double pole switched fused spur outlet, protected by a 13A fuse.

there doesnt have to be any electric showers at all. the idea of the electric showers was only if it would significantly reduce the setup cost of the heating system because it wouldnt have to supply as many showers. if it makes no difference then the showers can all be fed from the heating system if needed, or at least 1x electric in the common access bathroom just incase there is a fault with the heating system.

 

[Jasonss]

single phase

 

[RF Lighting]

1 shower.

 

[Iggifer]

You will struggle to supply 5 showers from any single heating system. The new build flats I'm working on at the moment has 2/3 showers fed from a pressurised cylinder. The rest of the rooms are electric showers. Could probably push it to 4 but I suspect the plumbers like an easy life .

If you run more than one hot tap at a time, notice the pressure drop, now multiply that by 5 - if everyone takes a shower at the same time, none of them are getting wet.

 

[Jasonss]

i was originally thinking of 3 from the heating system and 2 electrical showers.

 

[Echo the husky]

Have you seen this thread?

 

[Iggifer]

i was originally thinking of 3 from the heating system and 2 electrical showers.

Then fit one of these http://www.meteorelectrical.com/dis...ro-priority-shower-board-choose-priority.html

Note: you will be an unpopular landlord

 

[flameport]

single phase

Totally unsuitable for the proposed loads.

 

[endecotp]

i was originally thinking of 3 from the heating system and 2 electrical showers.

Then fit one of these http://www.meteorelectrical.com/dis...ro-priority-shower-board-choose-priority.html

Note: you will be an unpopular landlord

This one might be slightly less unpopular:

http://www.meteorelectrical.com/dis...r-board-non-priority.html?cpath=827_3_145_738

Seriously though - this is more like a small hotel / guesthouse system. Find a proper heating engineer who has experience with such installations.

 

[Jasonss]

just asked around, and 6 bed hmos are on single phase.
its not a large hotel, or even a small hotel, or a guest house, or an industrial unit.
its a house with 6 people living there. its just the same as any other 6 bed house.

 

[Taylortwocities]

Every morning six people will be wanting to shower at the same time.
Have to considered the logigistics of delivering that?

Electrically, with a single phase supply per the above

1 shower.

So other method(s) need to be considered.

 

[securespark]

its a house with 6 people living there. its just the same as any other 6 bed house.

No, it isn't!

I have a 5 bed house, there are 5 of us here and we have only 2 showers, one electric and one run from the boiler. It's rare that 2 people want a shower at the same time, but if that arises, then we can. But any more and we would be pushing it.

With a 6 bed HMO, it's not like a family who all know each other: people will want to be independent of each other (imagine the house like a small complex of flats) and they will have showers whenever they like. If you install what you propose, there will very quickly be a breakdown of supply.

I'm no plumber, but I would not employ any electrical water heating (apart from an emergency system for when the boiler fails) at all.

There must be a way of running multiple showers from a gas boiler: maybe install one for heating and one for the showers or somehow split the load in the HMO between two boilers?