Residential sprinklers in kitchens

[Northern Uproar]

Can anyone help with this one: we have had a question put us about the effectiveness of a residential sprinkler system in dealing with fires in 'white goods'. I can't seem to find much info to this precise question (the BRE report seems to focus around a lounge arrangement), does anyone know of any specific research carried out into this?

Thanks in advance.

[Chris Houston]

I don't know of any research.  But I'll throw in some opinion anyway........just for the fun of it.

Assuming we are talking about washing machines and fridges, it would seem to me that kitchen equipment that uses heat might be the more common source of fires - the cooker, chip pan and microwave.  But anyway.....

I would speculate that the fridge and washing machine tend to have flat, sealed metal tops and that we could not expect sprinkers to spray water into these, in the early stages of the fire they are going to provide some cooling and perhaps stop/delay the fire spreading to nearby combustible items.

The loss of the fridge, plus the associated water damage would for sure be a better outcome than the fire spreading to the whole kitchen or whole house and the inability of sprinklers to penetrate domestic electrical items like this isn't something I'd be worrying about, I'd be more worried about the bigger issue of the complete destruction of the property the life safety risk.

......while acknowledging that this isn't what you asked......

[CivvyFSO]

There should be no need to be this precise. I doubt research will have been done on something so specific because it will not have been flagged up as a risk. Sprinklers are not expected to always extinguish a fire, and to base any strategy on sprinklers actually extinguishing a fire would be a gross miscalculation. It might also depend on whether you are looking at a 'residential' system or a 'domestic' system, as they both perform relatively different functions.

[Northern Uproar]

I don't know of any research.  But I'll throw in some opinion anyway........just for the fun of it.

You've got to love what you do, Chris!

Thanks for the replies. I acknowledge the limitation of sprinkler systems in that they supress fire growth instead of extinguishing, but the question I as given was quite specific, and was concerned that there was some school of thought regarding the provisions in a domestic kitchen that is creating doubt about this, but also acknowledge that fires in tumble dryers etc are not uncommon. I have spoken to a sprinkler certifier who suggests, like Civvy, that the question is too precise and that risks within a flat are addressed within the flow rates provided in the standard, and that it points out that large scale cooking facilities are not covered and should be a 12845 system, but this isn't the case in this particular instance.

[Mike Buckley]

I don't know of any research, however given the operating temperature of the sprinkler heads, the fire would have to have grown quite considerably and have spread beyond the white goods before a head operated.

I would agree about the effectiveness of sprinklers just providing water to the exterior of the machines and not being able to penetrate inside the unit. Any alternative is a water mist system where the finer droplets are more likely to penetrate inside the units. I have seen video of this system extinguishing a fire underneath a solid surface.

[John Webb]

Friends of mine lost a kitchen through a fridge motor overheating and catching fire. Spread to other objects in the kitchen was mostly through vertical spread up the wall behind the appliance and then sideways to wall cabinets. The smoke spread to the rest of the (holiday) apartment and heat damage was limited to the kitchen, the door having been left shut.

My guess is that while a sprinkler would not have controlled the initial fire, the spread once beyond the appliance's casing would have been limited considerably, so damage would have been less with a smaller amount of heat and smoke production. Also the spray would to an extent 'wash' the smoke out, so smoke spread would have been much less anyway.

You might wish to try giving Dr Corrine Williams at BRE a ring - switchboard is 01923 894040.

[GB]

I have been to a domestic fire involving a washing machine in the kitchen where the sprinkler head actuated confining what became a smouldering fire within the space underneath the worktop - it was most effective.