Castanet

CrystalCity wrote:It's also part of the current troubles facing strata's in BC when applying for insurance because of the required proofs of adequately maintained fire suppression in the condominiums. They have to show that the internal water tanks are full. Those asking about pumping water from the base of the condos in the other threads...well it goes to a use in fire suppression. Each floor has its own "hydrant" built in.

Fire suppression systems, such as sprinklers (those little things in the ceiling) are designed to contain a fire until fire crews arrive, not to replace them. I have one installed in my house, so I know what they are. Fire hydrants on each floor in larger buildings (those boxes hanging on walls with rolled up fire hoses inside) are just pipes and hoses. If they were connected to residential plumbing, you wouldn't get a *bleep*-stream out of them. Usually, there is a fire hose hookup near the main entrance of the building on the street level where fire engine feeds water into those hydrants on each floor. Other than having ladders, and seats for crews, fire engines are just big water pumps on wheels. They take water from the main, and pump it into the building. The taller the building, the bigger pump you need.

My question was, who's paying for adequate fire engines in this deal? I don't know, because I haven't seen it. But in my opinion, every Kelowna taxpayer should ask the City that question.

BC Landlord wrote:The problem would be pumps. You would need at least 1,200 Psi for water just to trickle at 2,700 ft. At 470 ft it would be over 200 Psi. And that fire hose needs a lot of volume. To get a proper flow at the end of that hose (>500 Gpm), you would probably need ten times that pressure. I am not saying it's impossible. Some taller buildings have big water tanks at the rooftop to feed sprinklers system, or they feed water to fire hydrants (on every floor) from a bad-*bleep* fire engine.

Not every fire engine is good for these heights, and probably none of Kelowna's FD. I am not sure what the deal is with the developer here, but if Kelowna needs new fire engines, just because someone wants to build skyscrapers, who's paying for them? Taxpayer?

When pumping water we used half a pound pressure loss for every 1 foot in elevation. We also take into account the hose diameter and amount of hose deployed to achieve the desired pressure at the nozzle. With 1 1/2 or 1 3/4 inch line we tried to get 100 psi at the nozzle and the 2/1/2" line around 60 pounds.( controllability) If you try and push too much water, ( higher psi) the turbulence in the hose makes the increase in gallons/min negligible. Smaller diameters may get upwards of 200 gal/minute and the 21/2" line may achieve 300 gpm.
A fire in a high rise will result in the sprinklers setting off at the impacted location. A fire truck will attach a supply line from a hydrant and then attach lines to the fire connections located outside the building. The fire truck will boost the pressures to a point and that will get more gallons onto the fire. We tested hoses to 300 pounds once a year so I don't think they will go much more than that.
Taller buildings do have reservoirs on the upper floors and those feed the sprinklers. Because of the head, the water is relayed up to the reservoirs, much like a municipality water system.
Fire trucks have various sized pumps in them. Bigger pumps require more HP. many trucks have a 1050 or 1250 pump in them. Plenty for most structure fires. North Van City had some 2500 gph trucks as they had some big exposures at the water front.

A tall building is never fire proof but we always wanted to know or was aware what the fire load was or might be in any building.

I think Kelowna would be fine with a high rise regarding apparatus, manpower is another issue.
Sometimes if a developer has a grandiose design, they have sprung for the cost of a fire apparatus to deal with it.

seewood wrote:When pumping water we used half a pound pressure loss for every 1 foot in elevation. We also take into account the hose diameter and amount of hose deployed to achieve the desired pressure at the nozzle. With 1 1/2 or 1 3/4 inch line we tried to get 100 psi at the nozzle and the 2/1/2" line around 60 pounds.( controllability) If you try and push too much water, ( higher psi) the turbulence in the hose makes the increase in gallons/min negligible. Smaller diameters may get upwards of 200 gal/minute and the 21/2" line may achieve 300 gpm.

Half a Psi/ft is about right. 0.43 is hydrostatic, then you get friction losses once the water starts moving. The smaller the pipe/hose diameter is, the bigger the losses are. However, 200 Gpm does not seem adequate, especially if you have to use more than one hose. As far as I know, minimum requirement for street hydrants is 500 Gpm, and some go well over 1,000 Gpm (commercial?).

A fire in a high rise will result in the sprinklers setting off at the impacted location. A fire truck will attach a supply line from a hydrant and then attach lines to the fire connections located outside the building. The fire truck will boost the pressures to a point and that will get more gallons onto the fire. We tested hoses to 300 pounds once a year so I don't think they will go much more than that.
Taller buildings do have reservoirs on the upper floors and those feed the sprinklers. Because of the head, the water is relayed up to the reservoirs, much like a municipality water system.

Exactly, but as I mentioned before, sprinklers function is only to contain a fire before fire crews arrive, usually within minutes. Water tanks can only hold so much water, and once it's gone, fire engine is the only source. Some fires take hours to put out.

BC Landlord wrote:However, 200 Gpm does not seem adequate, especially if you have to use more than one hose. As far as I know, minimum requirement for street hydrants is 500 Gpm, and some go well over 1,000 Gpm (commercial?).

Getting a bit off topic here but a VERY basic rule of thumb is the square footage of a FULLY involved room requires about the same in gpm to get ahead of the fire. Thing is we all agree water is heavy and a hose at the business end has several forces acting on it.
Watching rookies wrestle with any hose that is curved right behind them that wants to straighten out can be entertaining until you point out to have the hose straight behind you for a bit makes control easier. This is with either 60 to 120 PSI at the nozzle.
Crank the pressure up and the hose now becomes dangerous. Saw a 200 pound fire guy in full turn out and scba lifted off the ground when the pressure accidently was bumped up to 150 or so psi on a 2 1/2" line.
Pump operator may have a discharge pressure on his gauge showing 200 psi but through friction loss and elevation ( head) the net at the nozzle is 70 psi.
Street hydrant water volumes are all over the map. Depending on the pressures in the mains, Where the hydrant is in relation to the last pressure reducing valve, pipe diameters, looped or dead end line you can have 500 to 5000 gpm at a hydrant.
Now, what a fire engine can pull from a hydrant is another lesson......

In the olden days when those 2 1/2 to 3" stand pipes were poking out of the ground for fire water supply, most they could provide was maybe 300 GPM.

seewood wrote: Watching rookies wrestle with any hose that is curved right behind them that wants to straighten out can be entertaining until you point out to have the hose straight behind you for a bit makes control easier. This is with either 60 to 120 PSI at the nozzle.
Crank the pressure up and the hose now becomes dangerous. Saw a 200 pound fire guy in full turn out and scba lifted off the ground when the pressure accidently was bumped up to 150 or so psi on a 2 1/2" line.
Pump operator may have a discharge pressure on his gauge showing 200 psi but through friction loss and elevation ( head) the net at the nozzle is 70 psi.

You are talking 100 Psi at the nozzle, and that's fine, but if that nozzle is on the 46th floor, you would need an additional 200 Psi at the pump. There is absolutely no way around it. We are talking some 300+ Psi. Now, add a couple of hundred Gpms of flow to the equation, and we are talking some serious equipment. Do they have it? I wouldn't bet my life on it. Why would 12 storeys height limitation be still in force otherwise?

If they (the city) don't have it, then who is paying for it? That in my mind is the whole point of this discussion. Somehow, I don't believe the developer will be buying new fire engines.

BC Landlord wrote:Why would 12 storeys height limitation be still in force otherwise?

My understanding is the limitation is only for wood frame buildings. The local (City of Kelowna) bylaw states that for high rises every 6th floor above ground level must store appropriate fire equipment. Please site the alternative source to correct me if I am wrong.

That said 100 psi is what the hose is set at ground level but the engines are capable of pumping at greater force. Again the above local bylaw states that the internal private hydrants must maintain adequate pressure. The same is true if a hydrant is located on private property, such as being within the owners property line if a single family dwelling. The home owner is responsible for ensuring the hydrant is adequately maintained, that is they incur the cost.

CrystalCity wrote:My understanding is the limitation is only for wood frame buildings.

Wood frame structures are limited to 6 storeys in the building code. That’s provincial. The 12 storeys limitation is a municipal decision (as per the article). I can’t see any other reason for that besides their fire-fighting capabilities.

That said 100 psi is what the hose is set at ground level but the engines are capable of pumping at greater force.

That's right. And the taller the building is, the greater the force (pressure) is required. Not every fire engine is good for these heights.

I believe the code was changed provincially to 12 stories for wood frame structures in 2019.https://www.ubcm.ca/EN/meta/news/news-a ... anges.html

As for the local zoning height variance it's only regarding public access to sight lines and not with fire safety. It's stated point blank in sections 1.0 and 7.0 of Kelowna's C7 Zone Design Guidelines.

CrystalCity wrote:I believe the code was changed provincially to 12 stories for wood frame structures in 2019.https://www.ubcm.ca/EN/meta/news/news-a ... anges.html

I wasn’t aware of the change. But anyhow, why would councilors then debate changing it to 46 storeys? Such a skyscraper can’t be wooden, even if they wanted.

From the article:
In order to go ahead, council would have to approve a height variance from the present 12 storeys and 26 metres to 46 storeys and 141 metres.

Because each neighborhood block has been zoned under the BC Land Titles Act. I live in a strata and took the course provided by the CHOA (Condominium Home Owners Association) and BC Housing in the fall of 2019 which is why this info is still relatively fresh in my mind. Just because a parcel has been zoned in a particular way doesn't mean it must remain that way. The parcels were likely zoned decades ago.

BC Landlord wrote:You are talking 100 Psi at the nozzle, and that's fine, but if that nozzle is on the 46th floor, you would need an additional 200 Psi at the pump.

Water for fire fighting at the 46th floor is coming from above reservoirs, reservoir is being topped up via relay pumps. Much like in a municipality, as the reservoir is being drawn down, a switch at a preset water level tells the pumps below to pump up and refill the reservoir. The fire engine at the street will be boosting the water volume and pressures in conjunction to the water supply provided by building water connections to the main outside.

I have a question for any building engineers here, I'm thinking the water table in Kelowna is not too far down. Would this have an impact with a 46 story building? How do they build on old lake bottom sediment or to they drive piles to bedrock, where ever that may lie?

I believe they drive the piles down. From what I remember that is what was done for One Water Street, and Brooklyn.
https://onewaterstreet.ca/one-water-str ... -okanagan/

seewood wrote:
I have a question for any building engineers here, I'm thinking the water table in Kelowna is not too far down. Would this have an impact with a 46 story building? How do they build on old lake bottom sediment or to they drive piles to bedrock, where ever that may lie?

The answer is no. They're not pumping the water up from a well, they're pumping from a hydrant that has it's own pressure. They don't "suck" water through the hydrant or anything like that, only boost it's pressure if/when needed.

A more interesting question would be "Is hydrant pressure higher at low elevations?" therefore requiring less pumping. I don't think hydrant pressure is regulated so I believe pressure would be higher near the lake but in no way sure of that.

TylerM4 wrote:I don't think hydrant pressure is regulated so I believe pressure would be higher near the lake but in no way sure of that.

Yes it is, that's why hydrant caps are painted different colours, and it's actually illegal to paint them differently.

CrystalCity wrote: Yes it is, that's why hydrant caps are painted different colours, and it's actually illegal to paint them differently.

So why are they labeled?

Sounds to me like they're labeled/painted different colors to indicate the pressure anticipated. To me that would mean they're unregulated and to help make up for the varying pressures as a result of being unregulated they've instigated a process of painting the hydrants different colors.

In other words "Are all of the hydrants downtown painted with a color that indicates high pressure because they're low in elevation"?