Research Shows Copper Cylinders Save Over £227 Every Year

Recent research has proven that a copper cylinder with an Integron finned copper coil can provide savings of £227 per year compared to a standard stainless steel hot water cylinder.

The research was carried out at McDonald Engineers UK Testing Facilities to analyse the time it took for a 210 litre unvented cylinder from 13°C to 55°C.


The project was carried out under normal household conditions with a standard indirect household boiler and an ambient room temperature of 20.5°C. 

Three cylinders were tested – a standard stainless steel hot water unvented cylinder, a standard POWERflow copper unvented cylinder and a POWERflow copper unvented cylinder fitted with a high performance Integron finned copper coil.

Heat up times were conducted over 3 tests (see appendix 1 for full analysis) and a comparison was drawn from the average heat up times as below:

CylinderStainless Steel CylinderPOWERflow POWERflow with Integron Coil
Heat-up Time50 Minutes 47 Seconds37 Minutes 30 Seconds32 Minutes


The research found the POWERflow with Integron Coil delivered the best performance, reaching the required temperature 37% quicker than the stainless steel cylinder and 15% quicker than the standard POWERflow.

Based on doing 2 full heat ups every day, and using the current gas price 4.18p per kWh (Energy Saving Trust Price – March 2016), this is the equivalent of a 62p per day saving or £227.31 per year, by using copper unvented cylinder with the Integron coil over the stainless steel cylinder.

The standard POWERflow copper unvented cylinder also delivered impressive savings which equated to £160.74 per year.

McDonald Engineers’ Sales Director, Jamie Stewart, explained, “Copper cylinders are widely recognised as the most efficient on the market thanks to their improved thermal transfer properties however, the actual financial implications have never been quantified.”

He continued, “The annual savings are quite incredible however even if you take this over the 25year warranty period of the hot water cylinder, you could expect to save £5682. This further demonstrates the fact that copper hot water cylinders are the most cost effective hot water solution on the market."