Hot water in high rise buildings

Hot water in high rise buildings

You can ask any professional how to prevent them but you will invariably receive the same response, you can fix them but they are absolutely impossible to avoid. They are often the culprit behind damaged underfloor, flooring and drywall. They contribute to contaminated water supplies and poor flow levels.

They push insurance rates through the roof and residents to their limit. They are also the reason why more property managers are doing what they can to lessen the necessity of future leak repair by presenting their condominium boards with the Rikos solution. Nearly per cent of residential high-rise buildings utilize domestic hot water recirculation systems to provide hot water to taps on demand. The hot water required to service every suite moves constantly through copper pipes. This persistent flow, combined with the soft quality of copper, poor system design, and chemically-treated municipal water supplies, leads to a deterioration from the inside of the pipes in domestic hot water recirculation systems.

Even the most up to date leak detection methods and equipment sensors, acoustic leak detection, etc. Sadly, there are times in which deterioration only becomes noticeable when the inner wall of copper pipe reaches paper thinness, and springs a leak.

So miniscule that it may not even be visible from a distance, that tiny hole is one of hundreds that may be forming, or potentially exist already.

Over time, the rate at which they appear will only increase, as the interior of the copper pipe reduces to a fraction of its original thickness. The Rikos solution can be relied upon to more than double the service lifespan of the pipes within your domestic hot water system, as we employ an epoxy coating which adheres to the interior of the piping, sealing any potential leaks. That epoxy coating is resistant to the variables within your system which make pipeline vulnerable.

The Grand Canyon is a natural marvel in Arizona. Over the course of 17 million years, the Colorado Plateau shifted and gave way to the rushing Colorado River below.

Because of its malleability, cost, light weight, and relative durability, copper is used for domestic hot water pipes in 99 per cent of Canadian high-rise condominiums. During use, a semi-protective film forms on the surface of the interior of the pipe, useful for defending the pipe against corrosion. Unfortunately, a number of factors can lead to a breakdown of that film in concentrated areas.

When erosion corrosion reaches its breaking point, it manifests in a perforation of the pipe. Poor engineering and workmanship: A domestic hot water system designed with too many bends creates an unstable water velocity at certain points in the system regardless of tubing size.

Water rushing around corners, crashing into the interior wall of the copper pipe repeatedly at the same point creates a pitting in the pipe, leading to a small hole or fissure.

The same issue occurs when pipes are crimped by contracting companies using poor tools or or less than stellar methods during the bending process, or when pipes are improperly inserted into fittings before being soldered.

When a domestic hot water system is designed, it is integral that the flow rate in the penthouse is equal to that on the first floor. To compensate for poor design, often times a build company will utilize an over-sized booster pump to achieve proper water flow.

The velocity of water rushing through the pipes, as created by the grossly overpowered pump, creates a turbulence which leads to pitting in concentrated areas. This prevents the interior wall of the copper pipe to develop its protective layer, which leads to later problems.

Further, if a poorly designed domestic hot water system causes water stagnation within the pipes, soft water will victimize the copper quickly. This chemical treatment often inhibits the development of a protective carbonate layer within the interior of copper pipes. Without this protective film, copper pipes are developing leaks in buildings less than five years old.New York City is home to more than high rise buildings, typically defined as structures with 12 or more stories.

And that number is growing every day. According to the Wall Street Journalthe city is in the midst of what may turn out to be the largest construction boom in a generation, as hundreds of new residential projects have been initiated in the past year. Especially for luxury residential construction projects, high rise HVAC requirements are a prime concern. Buyers and tenants demand nothing less than consistent comfort, quiet operation, and even the ability to customize the heating and cooling of the space according to their individual requirements.

Yet for builders of high rise residential buildings, those needs have been tough to meet with the traditional high rise HVAC options. They tend to be noisy, inefficient, and they take up too much valuable space within the building. Heating and cooling high rise buildings presents difficulties not encountered with structures that have fewer stories.

For example, as the building increases in height, the air temperature outside the building decreases and the wind speed increases, which can impact the ambient temperatures inside as well as operation of outdoor equipment.

Skyscrapers above 60 stories high have the most difficulty with this issue. Also remember that heat rises, so heating and cooling requirements for the upper floors can be quite different than the lower floors.

The high rise HVAC system must be capable of accommodating the varying conditions throughout the building. Tall buildings also use a great deal of energy simply because of their size. Another problem is space. As demand for cooling in particular has increased, due to climate change, increase in power consumption and expectations of residents, the disadvantages of older high rise HVAC technology have become more problematic.

Packaged units These were the high rise HVAC system of choice for older construction at the time and are still used today especially in landmark buildings, due to restrictions in new holes through the wall. These individual units are installed through an existing wall opening and can only serve one or two rooms.

Water Supply in High Rise BUildings 2

They are also very noisy and an eyesore in well-appointed spaces. Individual split systems As opposed to a large, central building system, this option consists of individual units for each living space. These small, air-cooled units are installed with condensing units mounted under windows and on balconies of each apartment, and indoor fan coil units somewhere within each living space.

They are inexpensive to install, but the problem can be finding the space for the indoor units without giving up closet space or lowering ceilings heights to make room for ductwork.Crossover occurs when hot water crosses, usually through a defective fixture, into the cold water piping or vice versa. These hot and cold water systems are normally separate.

However, mixing points — such as single lever faucets — connect hot a cold and provide a channel for crossover. When hot water crosses into cold water lines the effect could be great enough to shatter a toilet bowl.

When cold water crosses into hot water piping it can result in a lack of hot water. A typical resident complaint is a sudden change in temperature from hot to cold or vice versa after setting the temperature just right.

Replace the cartridges in Moen faucets. Older Moen faucets are a frequent cause of crossover. Replacement Moen cartridges are available free from plumbing suppliers. Replace or modify designer Italian European faucets. Many require precisely equal hot and cold pressure and are not designed for the fluctuation present in high-rises. Replace them or modify them by installing spring- loaded check valves on supply lines. Replace cheap handheld showerheads and advise residents on proper operation.

Residents often turn on the hot and cold water at the tap and then press the button at the showerhead to enable the flow of water. When finished they release the button and leave the water on at the taps. The open valve s may be a crossover point.

Look for recent in-suite renovations. Investigate further. To determine if neighbouring risers are affected take the following steps:. Isolate turn off the hot water riser. Open cold water taps. The cold water should run properly.High-rise buildings present MEP engineers with a number of design considerations and challenges that are neither commonly addressed nor given formal guidelines for resolution.

The design of efficient and reliable plumbing systems in high-rise structures requires careful awareness of water pressure issues, water access logistics, heater efficiency, drainage problems, vent stack problems, and a myriad of other maintenance concerns.

By taking the size of these buildings into account, understanding the constraints imposed by gravity, and being aware of established plumbing design principles, any MEP engineer can tackle the numerous challenges that these formidable buildings present.

Low water pressure issues can derive from a number of sources. At times, low pressure may be attributable to an insufficient municipal water supply ; in such instances, it is necessary to implement a pressure-boosting system to compensate.

Nonetheless, internal plumbing problems may be the cause of water pressure issues in situations where the supply pressure is verified to be adequate. Keep in mind that unnecessarily implementing a booster pump in situations where insufficient pressure is due to internal piping issues incurs unnecessary energy costs; in addition, it may result in excessive water pressure that may damage valves, pipes, and any number of other elements in a plumbing system.

Fixing the system is preferable to bandaging it with a booster pump. Clogged pipes are often the culprit in causing low water pressure in old installations. There may or may not be external and obvious damage to the installation, only performance assessments can assuredly diagnose a blocked pipe issue. If the damage is not extensive, the piping may be refurbished and reused, otherwise, it may need to be replaced.

In addition to clogged pipes, insufficiently-sized piping and valve malfunctions may also cause flow and pressure restriction. High-rises are large, tall structures with internal plumbing systems that, to be in compliance with established building codesmust overcome the downward force of gravity and provide water throughout a building, top to bottom.

Plumbing in tall buildings requires high pressure-rated pipes to deal with the greater water pressure that these systems require to properly function. MEP engineers must consider the minimum required pressure for piping on the top floor of a pressure zone and ensure that aforesaid fixtures can adequately maintain pressure throughout peak flow periods.

Optimal design for a high-rise plumbing system uses a different booster pump for each pressure zone. Each pressure zone, depending on floor-to-floor distance, may span around 10 floors.

The top floor of the pressure zone must meet some minimum pressure requirement while the bottom floor of the zone is its most pressurized point, it is either at or below 80 PSI the maximum allowed by New York building codes.

A distributed booster pump set up is more efficient than a design that utilizes a single pump package at the base of a building, which is mediated by pressure-reducing valves to mitigate pressure on the lower floors ; such designs needlessly waste energy. The efficiency of a water heater system does not necessarily correspond with optimal cost-savings; regional energy price differences are more influential on water heating costs than individual design nuances. In some areas, such as New York, natural gas rates are far cheaper than electricity, rendering a natural gas solution far more attractive than an efficient electrical heating system.Around towers are currently under construction or in the planning phase in the capital.

They vary between 20 and 60 storeys — around 80 to m high.

Hot Water Recirculation in High-Rise Buildings

Tall buildings pose unique design and engineering challenges and opportunities — particularly in terms of maximising floor space and reducing the energy used for heating and cooling. Gone are the days when each apartment would be fitted with an individual gas boiler. Most newly built residential buildings now utilise district and community heating or centralised boiler systems.

This can optimise the efficiencies that dense population living provides and enable the use of low-carbon energy sources such as combined heat and power CHP. However, the efficiency of the transfer from production of energy to the end user is still key to maximising the potential energy savings. This is where low supply and high differential temperatures, working with a diversified heat load, can reduce energy loss between the energy source and the dwelling.

In tall buildings, system pressure becomes a major issue and is critical to the design and layout of services. In simple terms, the static pressure in a heating and cooling system is 0. Add in the dynamic pressure from the pumps and a breach of the 10 bar maximum pressure rating, that is common for some types of pipework, radiators, and underfloor heating manifolds, will occur.

You will also commonly breach the 16 bar maximum pressure rating for pumps, valves, and boilers. Rather than uprating components to deal with these high pressures, and so increasing costs, the most commonly used solution is to break the system into two or three sections using heat exchangers.

In tall buildings heat exchangers can be used to take the energy from the low pressure plantroom and transfer it into the high pressure secondary side, where it is distributed to apartments. Having one exchanger serving the lower section of the building and another serving the top half of the building can minimise the components exposed to the high system pressure experienced in the building. Location of these heat exchangers varies in different building designs, but apartment building designers tend to favour the basement rather than halfway up the building.

When selecting pressure-breaking heat exchangers, any loss in the exchanger represents unused production of energy. Efficiency of exchange should, therefore, be the primary consideration when specifying these products. With this in mind, Danfoss has developed a range of plate heat exchangers that delivers exceptional performance, efficiency and flexibility in a compact design. All of this can result in a smaller, more efficient transfer of heat, with minimal temperature loss in the exchange.

These heat exchangers are designed to meet the needs of virtually any heating and cooling application — including heat networks and centralised boiler plants. In high-rise buildings, they can be used as pressure breakers for heating, cooling and hot-water production. Efficient control of heat exchangers is also an important factor in effective distribution of heat.

Utilising pressure-independent control valves makes it possible to combine a differential-controlled balance with high control-valve authority.

This ensures the system achieves the design temperatures and matches the requirements of the system load. Indeed, Danfoss can design and prefabricate a complete packaged unit to a bespoke project specification.

Servicing high-rise living

This package would typically include the Micro Plate heat exchanger itself, a pressure-independent balancing and control valve, ultrasonic energy meter, controls, pumps, strainers, and ball valves — all delivered as a single component ready to be installed with just four pipe connections. Kevin Pocock of Mitsubishi Electric discusses the drivers for universities to achieve zero carbon in their built environment — and the challenges.

Coming Soon! Coming soon — exclusive content for MBS subscribers. Home News Analysis Servicing high-rise living 05 May, The dimple pattern design of this plate heat exchanger increases heat transfer and reduces pressure loss.

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Water has the unfortunate quality of being heavier than air.

​Domestic Hot Water Recirculation Systems

In fact, it weighs This mass requires a pressure of 0. To put it another way, one psi will lift water 2. In a single story building with 70 psi in the street, this can be insignificant. In a high-rise building, this factor will drive the design of both the hot and cold water systems. I don't know why anybody would want to live in the penthouse. The water pressure is dismal up there. To avoid this, the plumbing engineer needs to pay careful attention to zoning the water systems.

First, high and low pressures need to be determined. Plumbing codes usually limit the high water pressure to 80 psi. Using 70 psi will result in more manageable flow rates at the fixtures, reduced water hammer and lower velocities. These characteristics will result in lower operating costs and a longer life of the system. Codes often limit the low water pressure to 20 psi, unless there are fixtures such as flush valves that require greater pressures.

Nevertheless, a minimum pressure of 40 psi is recommended for the comfort of the end users. With a pressure differential of 30 psi, a zone can be no more than 69 feet in height 30 ft x2. Using a typical floor to floor height, for a hotel, of 11 feet, no more than six floors can be served by a single zone.

hot water in high rise buildings

The next step is to determine the system pressure. The suction pressure can be determined by adding the street pressure and the elevation gain assuming your booster pump is in the basement. Adding the anticipated losses including friction, elevation and PRV falloff to the minimum pressure results in the system pressure.

Subtracting this from the street pressure yields the boost pressure. The manufacturer will also need to account for internal losses in the booster pump system. Booster pumps today can be configured in any number of ways.

With advancements in pumping technology, vented roof tanks are a thing of the past. A constant speed pump, carefully calculated, could operate without PRVs.

If so, PRVs might be required at the top floor, and shutoff head must be checked. Shutoff head is the system pressure resulting from the demand approaching zero. It can be determined by adding the suction pressure to the pressure indicated on the far left end of the pump curve. In some cases, this pressure can exceed the capacity of the piping system. If PRVs are provided on the pump discharge, problems with shutoff head can be eliminated outside of the booster pump package but must still be checked within the package.

A better solution is a variable speed booster pump.While icy water in nature is a natural part of seasonal changes, no one wants it with their morning shower. In fact, cold water in showers and at faucets actually wastes money and resources.

Deppmann offers the product solutions for hot water recirculation systems ranging from simple single zone constant speed systems to multiple zone, multiple level variable speed systems. Why depend on flow balance when you are trying to achieve a temperature? This design assures the integrity of the element by keeping it our of the water flow. Many competitive devices do not have this advantage.

hot water in high rise buildings

Whether you have a question about the product or want information on product availability and pricing, we've got you covered. One challenge with Domestic Hot Water Recirculation Systems is the setting of the flow balance valves.

These valves will modulate to maintain the flow rate. Any over head of the pump is taken up by the balance valve. This prevents too high a velocity in the copper pipe in an unbalanced system. They may be dialed down to eliminate over heading in pumps. Some may also vary the speed in response to changing loads. The traditional domestic water recirculation system goes back in time a long way. At the end of each hot water plumbing supply, the engineer adds a manual combination balance and flow measurement valve.

From there, a small return is piped to the water heater. The pumps are normally small factional horsepower constant speed pumps. The difference between them is capacity, starting power, cost, and energy saving potential. The selection of balance valves, recirculation pumps, and system design can vary dramatically.

The R. Deppmann series "HRR" zone recirculation package will assure proper flow to all floors while provided the best use of pumping energy.

Why You Have Pinhole Leaks

This package is pre-assembled with all of the components required. Specifying this package saves the engineer design time while providing unit responsibility for the operation of the system.

Traditional domestic water recirculation systems in single pressure booster high rise design normally follows a simple design. One design, shown here, has a pump for each zone. This leads to multiple pumps with very low flow rates and high heads.

hot water in high rise buildings

If a single high head pump is used there will be a balance problem. Upper zone balance valves will be throttled so severely that they may plug or create a whistle noise. We have all experienced the frustration of turning on the shower and having to wait for the water to get hot. It doesn't have to be like that. Smaller commercial and home systems may or may not have a dedicated return piping system.

Most of us know the frustration of waiting until the shower water gets warm. Wasted time and wasted water. It is simply installed between the hot and cold water lines.


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