Hot water in the home is an essential requirement and it is estimated that the cost of using electric water heaters accounts for over 33% of the average household electricity bill. Understandably solar hot water heaters are becoming increasingly popular as not only in the energy largely free but also there are ecological benefits from using renewable energy sources.

How does a Dayliff Solar Water Heater Work

The principle is simple – cold water is fed into the integral storage tanks from where it circulates through the adjacent solar collector using the principal known as thermosyphon that results from the temperature differential between the top and the bottom of the unit. The collector is a series of capillaries attached to copper sheeting that collects the sun’s energy and heats the water as it flows through. Hot water is then stored in the insulated tank for use when required. Dayliff solar water heaters also feature an auxiliary electric heart as standard so that hot water can also be supplied when the sun’s energy is low.

Selecting a Solar Heater

Solar heaters are available in different sizes depending upon demand and available solar irradiation levels. Dayliff systems are supplied in three basic sizes with options of 160l, 220l and 320l tank capacity which typically are suitable for household of 5, 7 and 10 people. The amount of irradiation is also important so systems are supplied in two specification levels, one having a larger collector area for more temperature climates, for example in Nairobi. Generally the tanks are fitted on a frame together with the collector and sit above it on the roof. However, for aesthetic reasons this is sometimes not acceptable and it is possible to fit the tank under the roof providing it is above the top rail of the collector. This requires a sufficient roof pitch. Also available are the option of direct and indirect systems, the latter being applicable if the feed water is lightly mineralized with a tendency to corrode and block the capillaries. They work by separating the feed water and the heating water which circulates through the collector to a jacket around the tank and transfers heat to the feed water by induction. These systems are less efficient, though have applications at the Coast.

Solar Water Heater Installation

There are three golden rules of Solar Heater Installations – they must be exposed to as much direct sunlight as possible and so must not be shaded, they should be installed at a pitch of about 150 and the main axis should be oriented North – South with the panel facing South in the Northern hemisphere and vice versa. By following these simple rules the heat input will be maximized. It is also important to ensure that the system is suitably plumbed so hot and cold water pressures at the outlets are the same. This is simply done by arranging the solar heater’s feed from the main cold water supply. Tanks are rated at 3.5Bar so the system supply can be rated to this pressure to give full water flow at the outlets – generally the gravity supply should be avoided as outlet pressures are too low and a booster pump should be fitted.

Solar Heater Usage

As there is only heat energy in the day solar heated water is only available once in a 24 hour period; if it is used in the evening there will be insufficient hot water in the evening. All Dayliff heaters therefore provided with an electric booster heater that can be fitted with a timer so hot water is available in the morning. If electricity is not available hot water use must be managed accordingly.

Unquestionably solar hot water systems are effective and of course save considerable power costs and considering their inherent advantages as well as legislation that is making the fitting of solar heaters compulsory on new buildings their application will increase. If correctly sized and installed they are now both highly effective and reliable, though it is also important that they are robust and designed for high efficiency. Dayliff solar heaters are tried and tested and with the benefits of a high efficiency Turkish sourced collectors and long life GRP cased tanks are particularly suitable for local conditions. Dayliff systems are also backed by experienced application engineers who will ensure a properly specified and engineered installation.

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19th Sep 2020

Are you among those who are fed up of the frequent power outages in the country? Many people have to make do with only three quarters of their power supply needs yet the bill at the end of the month never seems to reflect this reduced usage. Because of this unpredictable supply, a good number of Kenyans are turning to solar power to fill in for the erratic power supply. In the past two years, the number of companies selling solar power equipment has risen noticeably to the extent that there is currently a glut in the supply of cheap, Chinese-made solar panels in the global markets. But although this oversupply is yet to be felt in the Kenyan market, all indications are that it will soon be with us. Already several companies are aggressively advertising the products in the media.

The cheaper prices will make it more affordable for urban residents to put up solar panels on their roof tops allowing them to run some of their appliances on solar. Prices for solar panels, available locally are today approaching KShs.150 per watt, half the price they were retailing for two years ago. A watt is the smallest unit of power. Locally produced panels in Naivasha, retail slightly higher at KShs.200 per watt. All signs point to the prices of the panels falling down to KShs.80 per watt – a price at which the solar industry is said to have reached grip parity, which is the point at which generating electricity from solar power is equal to or less than the price of purchasing power for the Kenya Power grid.

This drop in price should come as a welcome relief for most home owners because it will cushion them from high electricity costs and make up for unreliable supplies by Kenya Power, which is the sole provider. The cheaper price of panels is also trickling down to those in the rural areas because more kits that are more suitable for the rural areas are coming into the Kenyan market. The increased uptake of lighting solar kits in urban and rural areas coincides with report by Solar Electric Fund (SELF) that Kenya is emerging as a world leader in the adoption of solar equipment per capita. SELF is a US based body that has been advancing Solar Solutions to rural villages across the globe since 1990.

Increasing adoption

The report further says that more Kenyans are adopting more solar power in a year as opposed to making connections to the country’s electricity grid. An informal survey around some of Nairobi’s high end estates like Karen, Runda and Kileleshwa to name a few, reveals that most houses now come with solar water heating panels. In Karen, a whole estate was recently put up uses more solar power than electricity such that even the street lighting there is solar powered. This state of affairs is reflectd in the sales volumes recorded by companies like Solar Cookers International, Davis & Shirtliff and Chloride Exide and Kenital – among others – that deal in household solar gadgets over the last one year. The popularity of this alternative source of energy is partly explained by the fact that with solar connections, you avoid the long bureaucracies like the ones associated with applying for connection to the conventional systems.

Another reason that is advanced by these service providers for the rising popularity of solar energy is the fact that it adequately serves both poor home settings and the well to do ones. A drop in price of solar powered gadgets as recently reported by the Energy Regulatory Commission is another pointer that things are looking up. Although the newly gazetted regulations for Residential and Commercial Buildings which stipulates that buildings that need more than 100 litres of hot water a day should incorporate an in built solar heating system is yet to take effect, the trend is a shot in the arm in meeting this legal framework. It suffices to mention that the shift is not only limited to heating also installation of lighting systems, both indoors and outdoors. Many homes are opting to install both heating and lightings systems as the main source of energy. John Amayo of Solar Cookers International says that Kenyans are quickly embracing solar as a major source of energy because it’s cheaper and more reliable than what is currently available. “As a country, we are currently witnessing an overwhelming departure from the conventional sources of energy to solar technology,” he explains that the rate of adoption have been higher in Kajiado, Kisumu and Mombasa where they rolled out pilot projects in 1998 to popularise usage of solar for household energy solutions.

“The adoption cuts across the different classes of the population in these areas and save for Nairobi County which leads in connectivity, the three mentioned above are unmatched by any other part of the republic,” he offered. Amayo further explains that lately, even the laggards who were not keen on walking the solar path are choosing to have solar installations exist side-by-side with their conventional electrical connections. This scenario is projected by Tor Rafoss, the proprietor of Dala Rieko, community based organisation (CBO) that relies on solar power to run all operations within the organisation. The organisation specialises in making farmyard manure out of the water hyacinth in Lake Victoria.

“Although we are connected to Kenya Power, most of our machines are solar powered.” Says the Norwegian who divulges that solar as a green source of energy is cost-effective. He says that solar heating appliances are available in varying capacities and are able to operate even during cool days when the sun’s rays are not very strong. “Different from electricity that cannot power heavy appliances when the voltage is low, solar heaters are made in such a way that they have backup energy storage that it relies on when the supply reduces.” He explained. There is however one fact that all these suppliers confess, the initial costs of installation is high. But despite this, it has also come out so strongly that when spread over time investors in solar energy save up to 80% of their energy expenditures. Deputy Group CEO of Davis & Shirtliff, David Gatende, encourages households and commercial holdings to invest in solar energy saying it will eventually give value for the money you spend. “while the initial installation costs may be quite expensive, once you install a solar water heater or other solar powered systems, your water heating bills should drop by between 50-80% and within two years , you will have recovered your initial investment.” He exuded.

The CEO revealed that they have rolled out the second generation Dayliff solar water heating systems as a Kenyan solar power brand to make the equipment even more accessible. When fully operational, he says, the initiative will enable households to save up to 60% of their current utility bills. “Among the new models unveiled feature an indirect heating version for mineralized water and also greatly improved tanks with additional corrosion protection provided by cathodic protection,” he explained. For your house to be connected to both lighting and heating purposes, Evans Mitune, a registered electrician with the Energy Regulatory Commission says that an inverter must be installed to tap and change the power into a format that electrical appliances can use. Power from the solar panel is harnessed as Direct Current which must be transformed to alternative current format that most appliances are configured for.

The other requirements for conventional installation like issuance of quotation apply. Mitune says that the cost of installation constitutes a third (30%) of the total cost of materials. He also explained that the overall cost is also determined by the number of lighting and heating points increases the connection cost by at least KShs. 2,850 whereas that used for lighting needs KShs 1,500. Available in the market at similar prices to conventional electric appliances are solar refrigerators and freezers that are energy efficient. The two, PF 166 and PF 240 which are maintenance free, work with an input voltage of 12V and 24V respectively.

By Justus Wanga

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19th Sep 2020

BY Tom Jackson

There was a time when even the clearest of blue swimming pools came at a hefty cost in chemicals, health and the environment. But not today, with 4/5 of all the new swimming pools going into Kenyan homes and institutions now being saltwater pools with lower running costs and none of the same side risks.

Saltwater systems are not chlorine-free: the difference is that they use chlorine generators to make the chlorine from salt, rather than adding concentrated chemicals. It’s a shift that has enjoyed galloping technology in recent years, with 80 percent of all new installations now using a chlorine generator”, according to Moses Kitheka, Sales Engineer at Davis & Shirtliff. The company, which is the leading supplier of swimming pool equipment in East Africa, has seen a boom in people turning to salt as an alternative to traditional chlorine.

Chlorine pools are now firmly associated with sore, irritated eyes and itchy skin, switching to saltwater creates a more natural, comfortable swimming experience. It is not the same as swimming in the ocean, where salt content is around 35,000 parts per million (ppm). The optimal salt content for a saltwater pool is actually less than a tenth of that, at approximately the same salt content as the human body. But the production of chlorine through a generator prevents the production of the chloramines that result in irritated eyes and itchy skin.

The electrolysis process producing the chlorine burns off these chloramines, meaning the swim is no less sanitary, but more comfortable and natural.

Environmentally Safe

The lowered use of chemicals, as saltwater pools virtually clean themselves, also makes the pool more environmentally safe and relieves the owner of the burden of consistently checking chemical levels. The salt systems also naturally inhibit the growth of algae. This natural process saves on both time and money when it comes to maintaining the pool, usually the most difficult and costly aspect of owning a swimming pool.

However , the initial spend on a salt water pool is greater, with a 200,000 litre pool requiring a generator costing Sh190,000 and a small 100 cubic meters pool requiring a generator worth Sh100, 000, which also come with additional costs for installation. Yet the technology makes financial sense in the long-term, with pool owners covering the cost of the initial investment within a few years through savings on chemicals and maintenance staff. In general, the cost of maintaining a salt water pool is less than half that of looking after the chlorine equivalent.

“Salt is 10 times cheaper than chlorine, “said Kitheka. “ Handling salt also requires a lot less care than handling chlorine”. With the generator producing chlorine whenever the pump is running, there is no for purchase, storing or handling of chemicals. There are also health benefits to the saltwater option. Pure chlorine pools create organochlorines with the ability to mimic human hormones. These can caused reduced fertility, abnormalities in the immune system and various cancers.

The same chloramines that cause discomfort to the eyes and skin have also been found to cause or worsen emphysema and asthma, meaning the saltwater option is more beneficial to those suffering from either illness. Moreover, where organochlorines and chloramines are a standard feature of chlorinated swimming of chlorinated swimming pools, in a salt water pool levels of chlorine never drop low enough for them to form.

As long as the pump is running, the generator will produce enough chlorine to keep a pool clean and comfortable without the hassle and negative repercussions of purchasing concentrates and swimming in heavy chlorine. It’s a cocktail of bonuses that have now seen salt water move to market dominance, and look set to mark the fading out of the old, blue pools of chemical concentrates.

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19th Sep 2020

With a wide range of backup generators, Davis & Shirtliff can help saving businesses or ensuring modern comfort when electricity grid is failing.

In this modern era a stable and reliable electricity supply has been taken for granted in the developed world, though in Africa many countries still fail to deliver this service to their citizens that affects private individuals as well as companies, big or small, and can have seriously damaging consequences on a business. Production machines cannot work, communication lines are broken and electronic equipment can be destroyed by sudden and frequent electricity breakages.

In aggregate it can seriously affect a whole country unnecessarily slowing down its development. For David Wanjohi Kagera, the factory manager of Highlands Coffee near Thika, a reliable backup was a simple necessity when he started designing the coffee factory late last year. Without it, the factory would have been unable to work during power blackouts. Planning would have been impossible and coffee beans would have gone to a waste being a loss to the thousands of small coffee farmers supplying coffee beans to the factory.

In reality, Highlands Coffee is unable to deliver and survive without having a reliable generator backup so they turned to Davis & Shirtliff for the supply of a 350kVA Dayliff Yanan generator which can run the whole production machinery with a capacity of 6 tonnes of coffee beans per hour. In addition, a 42kVA Dayliff Yanan generator is used as a backup for office facilities, security lights etc Mr Wanjohi is very satisfied and says “Seen over a whole year we expect mains electricity supply to be down at least 15% of the production time. Our backup generators from Davis & Shirtliff have been working perfectly well so far and they are crucial for our business. We have chosen Davis & Shirtliff for the job, because they are well known for their professionalism and reliability in their services.”

At the other end of the scale, smaller generators can also make a world of difference in business execution. Bridge International Academies is a network of high-quality, low-cost primary schools, supported by a strong central headquarters. Their “school-in-a-box” system is based on extensive use of technology to drive down school operation and support costs, thus enabling school staff to focus on their core job of ensuring student learning. At their central warehouse in Nairobi, they have installed a portable 4.6kVA Dayliff DG 6000S generator to ensure a constant reliable electricity supply to their offices from which the logistics for distributing inventory, school books etc is managed.

Warehouse officer Patrick Mussumba explains, “Our main electricity supply is erratic, when it fails, we have 30 people here who cannot work at full capacity. Our 84 academies may not get the supplies they need on time. In the end, the pupils suffer due to the lack of electricity in the warehouse. Since we got the backup generator from Davis & Shirtliff, we have been operating at a hundred percent, so it means a lot to us and the academies we serve”.

Davis & Shirtliff offers a wide selection of generators suitable for applications ranging from small domestic and commercial to large institutional and industrial use. They are sourced from world renowned manufacturers including Lister Petter, Yanan, Cooper & Elemax. In addition, the company’s own range of Dayliff DG generators offer excellent quality and unbeatable value for money.

Whether the client needs a small portable standby generator or a larger and more powerful solution, Davis & Shirtliff can supply. Most large generators above 15kVA are skid mounted on anti-vibration mounts and come with a specially designed canopy for whether protection and noise reduction. Most also include an integral fuel tank with contents gauge and fully automatic mains failure operation is available as an option. In addition the range includes a wide selection of high speed units specially designed for standby use as they combine higher operating efficiencies with lower initial costs to provide more cost effective solutions.

Like the company’s well known water pumps, all power products from Davis & Shirtliff are fully supported with technical selection advice and service backup with clients enjoy the same benefits of well established network of dealers and service centres all over East Africa.

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19th Sep 2020

Q&A Water Equipment People by Kenya Farmer Magazine

Interview with Davis & Shirtliff Group Chief Executive, Alec Davis

Q. Davis & Shirtliff started when and for what reason?

A. The company was founded in 1946 by my father who had worked as a water engineer for the military in Kenya. The company’s primary business then was water supply, though today we have diversified into other product segments including boreholes, swimming pools, water treatment, solar and power generation.

Q. Describe the company and its scope?

A. Water Pumps have traditionally been our core business and we have developed from a project oriented organisation to one focusing on wholesale and distribution within East & central Africa. The strategy has been supported by the development of a branch network and Davis& Shirtliff today has 25 branches across the region. As well as developing business established markets we are now also focusing on new emerging markets such as Sudan, Burundi and the Democratic Republic of Congo.

Q. You are best known for what?

A. Our brand – Davis & Shirtliff is well known in our markets and is synonymous with professionalism and technical expertise. However, I would say that our core competence is distribution. Our approach to logistics is scientifically driven towards efficiency and we are well resourced with an extensive warehousing facility and a fleet of delivery vehicles. Our supply chain management expertise is a great strength that enables the group to sell a wide range of products throughout the network with low stockholding and at low cost.

Q. What’s the size of your company and what can be attributed to its growth?

A. With a workforce of over 340 employees at 25 sites, our primary focus has been to improve on our technical capacity. We have doubled our size over a period of 3 to 4 years and have managed our growth to a sustainable 30 % per annum. The principal growth drivers have been the expansion of our product lines, the increase in the number of branches, the growth of the market in general and our disciplined and focused approach. The trade environment in East and Central Africa is ever more competitive and we attribute our success to our company values of quality, integrity and continuous innovation and improvement.

Q. How strong is the company brand name?

A. Put it this way, we are known by our slogan- ‘The Professionals.’ Besides, the company has invested a substantial amount in building the brand which is now a household name within our markets.

Q. Describe the latest product and how the market has responded to it?

A. New products are the life line of any business. Market research has suggested that there are opportunities in waste water management so we have developed a water recycling plant that has been an instant success due to its user friendliness and flexibility.

Q. What makes the waste water treatment plant from your company unique?

A. Our waste water recycling plant conforms to international standards and gives the user the possibility of concealing the unit underground so as save on space and reduce the environmental impact while processing raw sewage into clean, safe water.

Q. What are prospects for the company?

A. The region is growing fast and the demand for water and solar related equipment seems to be on the rise. Increased development in infrastructure as well as general economic growth will drive the demand for the company’s wide range of products. Furthermore, i foresee Davis & Shirtliff retaining its competitive edge over other companies owing to the quality of its products and its competitive pricing.

Q. How does the company give back to the society?

A. The company has a well established corporate social responsibility plan. As part of its commitment, the company focuses on installing pumps that provide a sustainable water supply to under privilege schools and communities in the rural parts of Kenya. Last year Davis & Shirtliff completed 42 projects benefiting over 30,000 people.

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19th Sep 2020

The provision of water of suitable quality for consumption is a vital requirement in all societies. Mostly this is the responsibility of the public water provider, but as municipal supply becomes increasingly scarce there is a greater responsibility on the consumer to ensure that the water available is fit for human consumption. The challenge is to identify suitable cost effective equipment for the treatment requirement, Davis & Shirtliff, the acknowledged industry leaders, being especially well qualified to advice on this. Davis & Shirtliff have been providing effective water treatment solutions for over fifty years and specialises in the supply of a wide range of water treatment equipment to treat most prevailing conditions including turbidity, salinity, hardness, mineralisation and bacterial contamination. Equipment ranges in size from small domestic units to plants from small communities and the company has a treatment solution for most prevailing water conditions.

Domestic purifiers are a particular strength with a range of equipment sourced principally from So-Safe being offered. The range includes sediment filters, Ultra violet purifiers, reverse osmosis purifiers for mineralised water and extra fine filters that are suitable bacteria removal. There is also a large range of cartridges available that can be combined in series to treat specific water conditions. On a larger scale Davis & Shirtliff manufactures a range of plants for community application’s (e.g. Schools, Hospitals, factories, Estates etc.) including equipment for filtration, sediment removal, sanitisation, pure water production, softening, conditioning etc. and is the leading supplier for this type of equipment in the region. A wide range of chemicals is also available.

A new product that Davis & Shirtliff has recently introduced is a solution for waste water treatment, which is becoming an increasingly important requirement both for ecological and legislation reasons. A unique solution has been developed that provides for an equipment and design package that can be incorporated into pre-constructed treatment chambers. The fully automatic process involves settlement, aeration filtration and chemical dosage and very satisfactory results are being achieved with effluent discharge fully meeting prevailing standards. With all the products either being directly imported or manufactured in house Davis & Shirtliff can offer effective and cost competitive equipment with full lifetime service support. This combined with its unmatched experience and expertise enables Davis & Shirtliff to provide optimal solutions to all water treatment requirements, to have ‘The water you want from the water you have’.

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19th Sep 2020