Heat pumps: Winter beckons like a warm blanket


By Eamonn Ryan | All photos by Eamonn Ryan

Winter – a cruel time for many, through affectionately known as ‘geyser season’ to plumbers – is approaching, as temperatures start to plummet from April onwards. It’s also a time when lots of insurance claims are made, and this holds the potential for upgrading geysers to heat pumps.


Plumbers who are savvy enough to send regular newsletters to customers should perhaps give their customers advance notice of the option to upgrade to a green, energy-saving heat pump should they be one of the unfortunate ones whose geyser pops. However, when that happens and their water freezes, panicked homeowners rarely think rationally – so the seed needs to be planted well in advance. Plumbers who are savvy enough to send regular newsletters to customers should perhaps give their customers advance notice of the option to upgrade to a green, energy-saving heat pump should they be one of the unfortunate ones whose geyser pops. However, when that happens and their water freezes, panicked homeowners rarely think rationally – so the seed needs to be planted well in advance. 

Many insurers allow policyholders the option to pay in the difference between the claim settlement and the cost of a heat pump (or solar geyser). It’s still a hefty cost, but with Eskom pushing the regulator for much steeper increases in its tariff in 2020, electricity prices may soon be going through the roof. It’s therefore a smart move for plumbers to suggest to customers to go for alternatives to their water heating needs. A heat pump can save up to 50% on water heating costs and it’s a great step towards greener living. And plumbers shouldn’t forget to remind customers – once installed, they need to add the heat pump asset to their building insurance cover.

The water heat pump market is being driven less by this replacement market as by new residential developments through the requirement that 50% of energy in developments must derive from alternative energy sources, stipulated by SANS standard 10400-XA. However, this has so far had little impact on the installed pool of traditional geysers. Insurance could be the spur to this market need.

“Electricity prices may soon be going through the roof. It’s therefore a smart move for plumbers to suggest to customers to go for alternatives to their water heating needs.”

Energy-efficient water heating devices such as heat pumps and solar heaters cost roughly double what a geyser does – but they can pay for themselves within two to five years based on various factors such as usage. For those with the spare cash, it is worth it in the long run.

Supplier companies involved in this business include: SA Heat Pump Engineers; Heat Tech. Kwikot, Stiebel Eltron; Thermowise; GMC; Alliance Air. Marketing of heat pumpsThe challenge for growing the market share of alternative water heating systems such as solar or heat pumps, is that the ultimate user – the homeowner – is never involved in either the decision to install or its replacement. The plumber, in turn, is not going to invest time in persuading a homeowner to go with one system or another: he receives instructions and it becomes a job like any other to be completed as rapidly as possible – he’s not there to do a selling job on alternative options.

When an individual purchases a house it comes with a water heater installed – he is not party to the choice. Thereafter, it is covered by manufacturer’s warranty and after that by the home insurance, which determines its replacement. The result is there’s a very low level of maturity in terms of energy efficiency in South Africa among homeowners compared to other regions like Europe. Although there is a SANS standard 10400-XA stipulating that 50% of water heating energy shall come from alternative energy heating sources, while building plans are duly signed off with such a provision, it is rarely implemented in practice, as enforcement is negligible in the inland provinces of South Africa.

The evidence is that in the residential market, 500 000 water heaters are sold each year, of which less than 40 000 are either solar heated (sales of which have flatlined at about 24 000 over the past five years after the huge spike from Eskom’s rebate system) or heat pumps (10 000 to 15 000 systems), a figure which isn’t close to half of 500 000. The percentage of occupancy certificates which are actually signed off is low. Considering the XA regulation has been in force for nine years now, the level of traction we have is less than 10%.

The water heater replacement market in depressed times such as these sits at around 60% to 65% of this market. For heat pump suppliers, it has always been a dilemma where to pitch the marketing drive for water heaters: replacing a water heater happens about once every ten years and it’s a grudge decision. So, one gets minimal leverage from advertising in publications targeting the consumer. Water heaters are also not sold alongside appliances, and it also has to be installed by a qualified plumber. It’s not something the consumer buys over the counter. The two motivations for a homeowner to install a heat pump (or solar system) is a neighbour who raves about the savings he is experiencing, or the rolling black-outs. Even in the case of load shedding a heat pump is not much help as it runs off electricity too, albeit just a third of the traditional thermal water heater. 

John Davis, technical manager at Gap Geysers, says that while the company is a major supplier of all three types of water heaters, he adds, “At the moment we find the market in South Africa is not big enough to be a serious part of it.”

“The market is certainly aware of heat pumps – the challenge is that at approximately R18 000, it is an expensive product when compared to an ordinary geyser at R3 000 or even a solar water heater at R9 000, thereby putting a cap on the market size.” Another constraint on the market is that the average plumber cannot install it – since it is more complex to install than a traditional geyser it requires specialist training and often accreditation to a supplier,” says Davis.

The case for heat pumpsHeat pumps use substantially less electricity to heat water than do resistance heaters such as geysers – by how much, depends on their particular technology and usage. All heat pumps have to declare their coefficient of performance (COP). Mines are major adopters of heat pump technology. The 20-year lifespan of heat pumps and modular design means that when a mine runs out of ore, it can simply lift the heat pump and relocate it to another mine. Mines utilise extremely large heat pumps due to the demand for substantial volumes of hot water in their staff shower-houses.  

Heat pumps come in two forms: as a split pump with an external attachment to the tank; or an integrated pump where the two are combined. In a residence where there is an existing geyser, it can be retrofitted to accommodate a heat pump. Although the savings on monthly electricity means the residential pay-back period may be four to five years, the retail market tends to find this too long, even though the savings over a ten-year period can be R70 000. It also requires annual maintenance which adds perhaps another month a year to the pay-back. 

Economies of scale Closer to the domestic residential end of the market with smaller heat pumps, is Stiebel Eltron. Niel Bosman, Stiebel Eltron Southern Africa technical sales representative, explains that the property market is being driven more towards renewable energy by the SANS XA requirements, though the problem is whether it is a heat pump or thermal solar, it is still a lot more expensive than a traditional geyser, “and if a heat pump comes close to the price of a geyser I would question its quality”.

Suppliers are able to advise on the design, he says. To obviate this mismatch Stiebel Eltron opted for the integrated system of heat pump and cylinder, as a single plug-and-play unit, as supply and return pipes are not required such as for a split system.

“All the calculations for specifying the correct system are done based on the end-user’s demands to maximise on electrical savings and is ideally suited to a standalone house with three or more occupants,” says Nico Jooste, Technical Sales.

Installation of a heat pump has to be done by an accredited technician – usually a qualified plumber who is also accredited by the supplier: either by SA Heat Pump Engineers locally, or in the case of Stiebel Eltron, trained and accredited in Germany. 

While large heat pumps are suited to, for example, mines where an entire shift comes to shower, the domestic ones would typically be suited to a family of at least three to be economically viable. Stiebel Eltron’s heat pumps are premium products which are meant to do more than supply domestic hot water (DHW), but can do underfloor heating and cooling, heat swimming pools and more.

The rooftop evaporator at The Village, Bramley.

“Although there is a move in the market to heat pumps, there is a lingering perception that they are not delivering on promised savings. For a heat pump to achieve its full COP it needs high consumption rates. Its COP is not high when it only has to moderately heat water.” Bosman explains that the average COP is calculated by the energy required to heat water from 25°C to 55°C, in a situation where the water tank is completely drained and the water fully reheated. When it is only partially used and the water temperature drops, for example, to only 45°C, the heat pump only has to increase the temperature by 10°C, it doesn’t have the opportunity to fully achieve the claimed COP. A heat pump is consequently suited more to massive usage than small draw offs, which means the heat pump is constantly and inefficiently heating water by only 10°C. You will still get a saving compared to a geyser, but not to the full potential. Perceptions of under-performance are consequently a result of the wrong-sized heat pump or water cylinder being specified; as well as pipe distances between the heat pump and the cylinder, which must be kept as short as possible. All this influences the performance of a heat pump and the efficiency you can get out of the system. This distance is often a factor of the building or house design, which the plumber can’t do anything about,” says Bosman. 

The affordability of a centralised heat pump system is affected by the number of units in a residential block. Bosman says, “There are certain costs and materials that have to be in the system, and the cost of these gets averaged out, reducing the cost per unit: if you go from an 80Kw to 160Kw system, it is not double the price. During school holidays when occupancy may drop to 50%, you still have all the fixed costs to supply only half the water it should and in that instance an alternative on-demand system like instantaneous water heaters may be more viable. On the other hand, with a solar water heating system you have to either increase your storage capacity or adapt your usage pattern in order for it to be efficient, by, for instance, only showering in the evening when the water is hot. With solar, the standby losses, especially on RDP houses is considerable, resulting in minimal hot water in the morning, thus the electrical consumption remains high due to the internal element being on to ensure hot water by morning.”

The biggest downside of solar heating, he explains, is that many buildings simply lack the space or facility to install solar panels and it is consequently not an option. 

The plumbers’ roleSA Heat Pump Engineers imports four different types of heat pumps from China, primarily at the larger, commercial end of the market. Heat pumps need regular maintenance – mainly cleaning. If one skimps on maintenance one can expect poorer performance and reduced life.

Some maintenance requires professional help – but much of it one can do oneself. SA Heat Pump Engineers director Godfrey Sutherland explains that its installations come with a one-year warranty during which it is responsible for maintenance which is performed biannually, and thereafter moves to a service level agreement contract. The complication with servicing heat pumps is they cross over between plumbing and refrigeration, requiring both expertise. Plumbing skills are consequently not integral to such servicing, he explains, as much of the skilled work relates rather to refrigeration.

“In some instances, they do the maintenance inhouse using our manual as the basis.” Properly maintained, he says, a heat pump will have a life span much longer than the repayment period. 

“We supply our heat pumps to plumbers who install them on site, and we provide them with the specialist training they require for this,” says Anton van Locherenberg of SA Heat Pump Engineers. “It is basic plumbing skills to install an integrated heat pump, no different to a standard geyser.”Sutherland says that while there is a steadily growing volume of enquiries for heat pumps at the moment, there are also more suppliers than ever in the market. “In 2008/09 it was quite a niche market, but since 2015 there has been a marked increase in players – more than the increase in demand.” Because the demand is primarily coming from new developments rather than replacement of installed geysers, demand matches new residential developments, and SA Heat Pumps finds there are a lot of old CBD buildings in Johannesburg being refurbished. However, the new development market has been affected by the demise of several of the large construction companies over the past two years.”

Sutherland says the maintenance of heat pumps costs about R700 a service and R1 500 to R2 000 for a commercial unit, but in the case of residential complexes the cost can be more than halved based on economies of scale.