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Should all new homes have fire sprinklers ?
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RenewableCandy



Joined: 12 Sep 2007
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Location: York

PostPosted: Thu Jun 29, 2017 10:01 pm    Post subject: Reply with quote

vtsnowedin wrote:
RenewableCandy wrote:

No I do not want a cold shower every time I do a stir-fry, thanks.

.

Perhaps a few cooking lessons are in order? There are settings for the stove burners other then high. Smile

Not for stir-fries there aren't. Unless you want soggy leaves, that is.
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vtsnowedin



Joined: 07 Jan 2011
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Location: New England ,Chelsea Vermont

PostPosted: Sat Jul 08, 2017 3:47 am    Post subject: Reply with quote

RenewableCandy wrote:
vtsnowedin wrote:
RenewableCandy wrote:

No I do not want a cold shower every time I do a stir-fry, thanks.

.

Perhaps a few cooking lessons are in order? There are settings for the stove burners other then high. Smile

Not for stir-fries there aren't. Unless you want soggy leaves, that is.

It would be a hoot doing side by side stir-fries. I seldom have enough left overs to keep a small dog from starvation. High heat when searing the meat ? Yes of course, but not turning it down and throwing the cover on to steam the vegetables without tripping a smoke detector? Haven't done that in years.
But if your family likes the results that is good enough for me as that is how I judge my own efforts.
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johnhemming2



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PostPosted: Sat Jul 08, 2017 9:46 am    Post subject: Reply with quote

It is all well and good having a sprinkler system, but if there is not enough water pressure for water to get through it it raises questions as to the merit.
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adam2
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PostPosted: Sat Jul 08, 2017 11:33 am    Post subject: Reply with quote

johnhemming2 wrote:
It is all well and good having a sprinkler system, but if there is not enough water pressure for water to get through it it raises questions as to the merit.


In most cases the flow and pressure available from the mains water will be insufficient and a pump will be needed, and often a storage tank.

This raises concerns about cost and complexity.

Politicians and civil servants love to add cost and complexity, so it is likely that standards will become more complicated and more expensive in years to come.
There is also a policy of reducing water supply pressures, so a sprinkler system that works from mains water this year may not perform properly in years to come, unless a pump is added.
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vtsnowedin



Joined: 07 Jan 2011
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Location: New England ,Chelsea Vermont

PostPosted: Sat Jul 08, 2017 12:15 pm    Post subject: Reply with quote

adam2 wrote:
johnhemming2 wrote:
It is all well and good having a sprinkler system, but if there is not enough water pressure for water to get through it it raises questions as to the merit.


In most cases the flow and pressure available from the mains water will be insufficient and a pump will be needed, and often a storage tank.

This raises concerns about cost and complexity.

Politicians and civil servants love to add cost and complexity, so it is likely that standards will become more complicated and more expensive in years to come.
There is also a policy of reducing water supply pressures, so a sprinkler system that works from mains water this year may not perform properly in years to come, unless a pump is added.
While older buildings with aged plumbing fixtures sometimes need a pressure reducing fixture to avoid blowouts there is no logical or practical reason for the distribution mains of a water system to have their pressure reduced. Most mains have a working pressure between forty and a hundred psi depending on their location and elevation compared to the water reservoir or pump station. Given that just one sprinkler head over say the water heater or furnace will deliver thirty gallons a minute directly on to the source of a fire and it's air tank will not run out so will be a great asset to the fire department.
You would only need a tank if you have a private well or spring with limited flow per hour.
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johnhemming2



Joined: 30 Jun 2015
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PostPosted: Sat Jul 08, 2017 1:43 pm    Post subject: Reply with quote

adam2 wrote:
In most cases the flow and pressure available from the mains water will be insufficient and a pump will be needed, and often a storage tank.

Which is quite a big issue with a tower block.
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adam2
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PostPosted: Sat Jul 08, 2017 2:53 pm    Post subject: Reply with quote

Tower blocks are easy. Systems vary, but one way of achieving protection is to use mains water boosted in pressure by an electric pump for the lower part.
Higher up, gravity supply from a rooftop tank gives good results, possibly with a pressure tank for the top floor or two floors.

With a tower block, providing plenty of water is easy as they are in urban areas, likewise tanks and pumps are easy. A secondary mains electricity supply or a generator is also feasible.

Anyway, new tower blocks DO have fire sprinklers, so someone has worked it out.

Much more challenging are houses and small blocks of flats with a limited and low pressure water supply and no secondary electricity supply.
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vtsnowedin



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PostPosted: Sat Jul 08, 2017 6:06 pm    Post subject: Reply with quote

adam2 wrote:
Tower blocks are easy. Systems vary, but one way of achieving protection is to use mains water boosted in pressure by an electric pump for the lower part.
Higher up, gravity supply from a rooftop tank gives good results, possibly with a pressure tank for the top floor or two floors.

With a tower block, providing plenty of water is easy as they are in urban areas, likewise tanks and pumps are easy. A secondary mains electricity supply or a generator is also feasible.

Anyway, new tower blocks DO have fire sprinklers, so someone has worked it out.

Much more challenging are houses and small blocks of flats with a limited and low pressure water supply and no secondary electricity supply.

I think you have that twisted around some. A thirty story 300 ft tall tower would need 130 psi static pressure at street level to get water to the top floor with each ten feet or rise losing 4.33 psi. The lower floors have plenty of flow and water either from the main in the street or from the storage tank on the top floor. Only the top two or three floors would need a booster pump.
If you look at commercial sprinklered buildings (at least in the USA) you will see on the wall nearest the street a water gong alarm that sounds when the sprinkler system is flowing and a fire hose fitting below it that the fire department can hook a fire hose to and pump water from the nearest fire hydrant to maximize pressure and flow when needed.
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adam2
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PostPosted: Sat Jul 08, 2017 7:25 pm    Post subject: Reply with quote

In most parts of the UK the mains water supply wont reliably reach above about the sixth floor.
The last building that I maintained had water tanks on the seventh floor (eighth floor in USA terminology) These filled from the water mains without any booster pump, but the inflow was very unreliable and intermittent in warm weather.
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vtsnowedin



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PostPosted: Sun Jul 09, 2017 12:31 pm    Post subject: Reply with quote

adam2 wrote:
In most parts of the UK the mains water supply wont reliably reach above about the sixth floor.
The last building that I maintained had water tanks on the seventh floor (eighth floor in USA terminology) These filled from the water mains without any booster pump, but the inflow was very unreliable and intermittent in warm weather.

I suspect some of your water mains are a bit long in the tooth. I see a good infrastructure project there that needs doing in any urban area where towers are being considered.
Your eight floor limit means you have just 35psi at the street and shower heads and such need 20 to operate satisfactorily and individual sprinkler heads work best at 40 psi and up.
Tanks and booster pumps are of course workable and probably cheaper then tearing up the street all the way back to reservoir if just a building or two is contemplated but a whole downtown would be better served with a high pressure system that did not need electric power anywhere except back at the water plant.
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kenneal - lagger
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PostPosted: Tue Jul 11, 2017 2:07 pm    Post subject: Reply with quote

Some of our mains are indeed in a very bad condition. We have one, under the main road into Newbury from the south, which has burst three times in the last three months and four times in the last year, all in a half mile stretch! It causes massive queues into town all day for three or four days. Thames Water are obviously not being charged enough for taking road space.
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emordnilap



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PostPosted: Tue Jul 11, 2017 2:24 pm    Post subject: Reply with quote

kenneal - lagger wrote:
Some of our mains are indeed in a very bad condition. We have one, under the main road into Newbury from the south, which has burst three times in the last three months and four times in the last year, all in a half mile stretch! It causes massive queues into town all day for three or four days. Thames Water are obviously not being charged enough for taking road space.


Nothing to do with privatisation then? Laughing
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Mark



Joined: 13 Dec 2007
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Location: NW England

PostPosted: Tue Jul 11, 2017 4:06 pm    Post subject: Reply with quote

adam2 wrote:
All common types of fire sprinkler react directly to heat AT THE SPRINKLER HEAD they are not activated by smoke as might result from cooking.
The usual activation temperature is IIRC 68 degrees centigrade.


The sprinkler heads have bulbs of chemical (alcohol ?) in them.
As heat increases, the alcohol (?) expands to a point where the glass breaks and water sprays from the head....

I only know big systems on industrial premises.
These are linked to a diesel engine which kicks in if a head is activated and will generally take water from an on-site water storage tank.

As well as excessive heat, you also need to protect heads from accidental damage....
Depends how hot and vigorously you like to Stir Fry....??
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RenewableCandy



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PostPosted: Tue Jul 11, 2017 5:00 pm    Post subject: Reply with quote

In the Mongolian Restaurant in Leith (Edinborough) they stir-fried your chosen meat&veg in front of you.

Sometimes the flames touched the ceiling.
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adam2
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PostPosted: Tue Jul 11, 2017 5:01 pm    Post subject: Reply with quote

Yes, many large industrial sprinkler systems use a low level tank and an engine driven pump. Others use mains water, if this be available in sufficient volumes and at enough pressure.
Still others use a pressure tank that is partly filled with water and then pressurised with air so as to drive out the water under pressure.

Domestic sprinklers are similar in principle and use mains water if this be suitable.
If not then an electric booster pump and often a tank will be required.
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