System efficiency and cost control

Bob Long, MD Eco Innovate Ltd
Bob Long, MD Eco Innovate Ltd

New designs and higher levels of sophistication continue to enter the heat pump market, but cheap heating is likely to be your customer’s only consideration, says heat pump specialist Bob Long

Assuming the customer’s expectations are practically achievable with the technology, all that is required for a successful outcome is a well installed system.

Understandably, with any piece of mechanical/electrical equipment, faults can occur from time to time, but in the case of a heat pump, the result of a fault situation can be very costly.

In previous articles I have discussed the value of fitting an energy meter, but MCS currently only demands installation of an energy meter for domestic users under certain circumstances.

Occurrences that reduce efficiency are not limited to air source heat pumps, and ground source systems can also be affected by numerous potential issues which lower economic performance.

The cause (and remedy) of most problems is best left to the technician, but identifying a problems’ existence is paramount to protection against excessively high running costs.

Many heat pump installations are fitted with bivalent support and failure of the heat pump can often go undetected, because bivalent support will usually provide the required degree of heating. bivalent energy is usually supplied from a more expensive energy source, such as electrical resistance heaters.

An electrically powered resistance heating source (immersion heater) can consume energy more than three times faster than the heat pump itself.

The RHI is designed to give financial support to assist in ownership of a heat pump system. This support is certain to attract customers from lower income brackets, who are keen to reduce energy bills.

Heat pump technology can, and does, reduce energy bills significantly, particularly for those in off-gas areas, but there is also the danger of unexpectedly large electricity bills, which could have disastrous consequences.

For the financially comfortable, a large electrical charge is extremely annoying, but for a household on the edge of fuel poverty, the result could be a step too close to financial ruin.

There are a number possible faults that can affect the performance of a heat pump, and the number of potential faults generally rise with the degree of system sophistication and complexity.

High electrical consumption can often result from a malfunction of the bivalent energy source embedded inside the heat pump, or the immersion heater, fitted to domestic hot water cylinders, and used for pasteurisation of domestic hot water.

The addition of bivalent energy to the heating system, and the pasteurisation process, are automatically controlled events and there is no visual indication of either of these processes in operation, and no visual indication when these processes operate for protracted time periods under a fault condition.

Subsequently, the system can potentially consume large quantities of expensive electrical energy, without knowledge of the bill payer.

There have also been instances where pasteurisation heaters have been energised, failed to reach their target temperature, and again resulted in excessive, prolonged energy usage.

I am not suggesting that these situations occur all the time, or with every heat pump system, but evidence and possibility is enough for concern.

Heat pump technology is here to stay and this is reinforced by one simple fact, that it is the most efficient way of using electrical energy to heat the home.

It is essential that any fundamental problems arising from experience, need to be dealt with quickly and effectively. If not, the industry could struggle to maintain credibility.