Water efficiency

By: Herman Strauss – manager: Alternative Energy & Fluid Technology, SABS

Water use has been growing at more than twice the rate of the world’s population increase in the last century, and, although there is no global water scarcity, an increasing number of regions are chronically short of water.

Water scarcity is both a natural and a human-made phenomenon. There is enough freshwater on the planet for six billion people, but it is distributed unevenly and too much of it is wasted, polluted and unsustainably managed.

We have been warned – and we dare not ignore the warning. South Africa is destined to face increasing difficulties maintaining adequate clean water supply. New information and predictions surface more frequently in the media telling the public about the looming crisis. Will we be prepared, or are we on our way to another crisis similar to the electricity debacle?

What can we do to improve the situation? We accept that many of the factors are outside the control of the plumbing industry. We can’t control the expanding population, we can’t improve municipal infrastructure and we can definitely not influence weather patterns. We can, however, make a difference through small contributions by plumbers and the like which can result in substantial differences.

The first and most important rule in water conservation is change in behavior. By being aware of water usage a substantial difference can be made. The plumbing installation itself should also contribute to this. By simply following the mandatory installation standards this will be achieved. Let’s look at a few examples.

What happen when you open the hot water tap at the kitchen and bathroom wash basins? You allow the water to run until hot water comes out before the cold water tap is opened to get the right temperature for washing dishes. How much water was flushed down the drain?

Hint: If the first few liters of cold water are collected instead of allowing it to drain away you can save on average between 1l and 4l of water every time you fill a wash basin with water – which amounts to considerable water savings over a year.

South African National Standards (SANS) 10252-1 :2012, clause 7.7.1.3, specifies that any ‘dead leg’ (the length of pipe from the geyser to the tap) may not contain more than 4l of water. This implies that the typical 15mm copper pipe may not be longer than 26,7mr or a 22mm copper pipe may not be longer than 12,1m.

The standard goes further and recommends that substantially shorter lengths should be used, which is 12m for a 15mm pipe and only 8m for a 22mm pipe. Study this clause as it provides more details.

What to do if you are faced with a situation where long runs are required? Consider installing the geyser centrally so that pipe runs in any direction are similar lengths. Also consider installing more than one geyser. Do pay attention to the sizing of the geyser. You don’t want to store an unnecessarily large amount of water for only a small usage. (Annex H in SANS 10252-1 provides excellent guidelines on sizing). Another solution is to install insulated hot water circulation loops, from where much shorter dead legs can be fitted.

Water is often wasted through a leaking, or activated safety valve. It is not uncommon for a valve to be leaking for hours or sometimes for days before it is noticed by the home owner. Even fully activated safety valves often go unnoticed for long periods of time.

By simply terminating the discharge pipe of a safety valve in an area that will easily be noticed by the home owner, such water loss can be minimised. It is after all a dedicated requirement to do so in line with SANS 10254:2012 (clause 5.2, c) (4)). Please keep in mind that the requirements in clause 5.2 are all critical to the safety of the installation.

It remains a concern if you find running taps in public parks and restrooms. It is unthinkable that somebody didn’t close a tap after use, yet it is noticed all too often. To address this, clause 5.3.1.1 of SANS 10252-1 requires that any tap installed outside a building that is not a residential building must incorporate a self-closing mechanism. It must be operated with a removable handle and it must either be of a demand type or be lockable.

This is further supplemented by clause 6.2.3 of the same standard that makes it mandatory to fit either a metering tap or a demand type tap in ablution areas with more than three taps.

So far we’ve discussed only installation requirements and haven’t yet touched on the requirements for specific components. For each component used in a plumbing installation, there is a SANS standard that guides its safety and performance. Individual water saving requirements are built into these standards. For example the SANS 821 that addresses dual flush cisterns, SANS 1240 for automatic shut-off valves for water closets and urinals, SANS 1808-16 for drinking fountain taps, SAN 1808-66 for demand type water taps and SANS 1808-9 for metering taps and valves.

The various installation standards contains many more regulations and guidelines that aids water conservation, as well as energy saving. By simply following the rules in place we can all contribute to making South Africa a better place for all.

Are your pipes worn out?

If your house is more than about 60 years old, make it an annual ritual to look at any exposed pipe—in basements, crawlspaces, and utility rooms—for telltale signs of trouble. Check under sinks in your kitchen and bathrooms. Here are a few tips to make sure your water is running smoothly

• Look for stains on walls and on surfaces underneath plumbing pipes that indicate leaks. Even if drips aren’t apparent, stains indicate a past leak that signals future trouble.
• Check the tubing for discoloration, stains, dimpling, pimples, or flaking, which are all indications of corrosion. If you find irregularities, bring in a plumber to do an inspection.
• Watch for leaks. Even small ones that are easily repaired may be indicators that the time for replacing plumbing for your whole house is approaching. It’s likely that the original pipes in your home are the same vintage, made of the same material, and they’ve been subjected to the same water supply and usage patterns.
• Look at the color of bathtub water when you fill it—especially after a vacation when water has been sitting in the pipes for a while. If the water looks brown or yellow, what you’re seeing is rust, a sign of decay inside the pipes. Consider replacing plumbing soon.

Over the decades, the water pipes in your home gradually corrode. Eventually, replacing plumbing is necessary. If you don’t, leaks may occur—and possibly a flood of water or sewage that can cause thousands of dollars of damage.

What is solar water heating

Solar water heating is a system for heating water by using energy from the sun. Solar energy is collected by a panel/collector, which is then connected by pipes to a hot water storage device such as a hot water cylinder.

Benefits of solar water heating

Solar water heaters can help save water heating costs by reducing the amount of gas and electricity needed to heat water. By using sunlight to heat water instead of combustible sources or fossil fuel-produced electricity, fewer pollutants are being introduced into the environment. Solar energy is not affected by the current shortage of electricity and does not stop providing hot water during load shedding.

How much of my total hot water requirements can a solar water heater provide?

A solar water heater can provide between 50% and 90% of your total hot water power requirements, depending on the climate and model of heater. When you don’t use the element you will save 100% of your hot water power requirements.

How hot can the water get?

The ideal temperature of your geyser or tank is between 55 and 60⁰C. Most solar systems heat the water to between 55 – 65⁰C, but some can heat much higher than that. You need to be aware of over-performing systems so that you are not scalded by the hot water.
Unless otherwise required the water temperature at the point of use should be at, at least 38⁰C for domestic fixtures such as baths, basins and showers and at least 45⁰C (in order to melt fats) for sinks. The temperature is not meant to exceed 55⁰ C at any point of use.

Dangerous plumbing practices?

After attending an industry function…I have to throw this one back at the whole industry.

In the gift pack, the company gave all guests an installation training manual; I would like to know if this is not a ‘dangerous practice’. Among the guests were plumbers, manufacturers, suppliers, etc. After a little discussion in the office, some people think they can do the installation without any problems, so how many people who received the manual think the same?

Installations should be carried out by qualified plumbers and no one else. Plumbing is a health profession and should be treated as such, it’s not as simple as some people want to make it out to be. This is the message which should be conveyed to consumers by the plumbing industry. What role does a training provider /manufacturer play in the industry to ensure these training materials do not end up in the wrong hands?