Cylinders for use with heat pump or solar heat source

SunSpeed domestic hot water cylinders are designed for use with heat pumps or solar panels. The heat exchangers are purpose designed for this application because: -

(a) The primary flow temperature from these sources will normally be significantly lower than from conventional heat sources e.g. gas boilers. Therefore heat exchangers with large surfaces areas will be necessary to transfer the heat at low temperature differences. (b)A second heat exchanger for conventional heat sources e.g. gas boilers will often be required. In this case the heat pump/solar panel heat exchanger must be of a compact design and capable of being fitted very low down in the cylinder.

Heat exchanger specification

The heat exchanger in a SunSpeed cylinder designed for either SOLAR or HEAT PUMP is manufactured from ‘Integron’ integrally finned copper tube and is only suitable for pumped circuits. In a SunSpeed 2, the heat exchanger i.e. coil for use with a conventional heat source is manufactured in either 22mm or 28mm plain copper tube to meet the requirements of BS1566 and Part L of the Building Regulations.

Performance

The ‘SunSpeed’ heat exchanger is designed to heat the cylinder water content from 10˚C to 49˚C in one hour with a constant primary flow temperature of 55˚C. The heat exchanger for use with conventional heat sources (e.g. a gas boiler) in SunSpeed 2 is rated to give the recovery time under 30 minutes as specified in BS1566. When a heat pump is operated during “off peak” electricity supply times only, then the heat exchanger rating should be matched to the heat pump output. For example a 450 litre cylinder may be designed to be heated by 7.5kW heat pump operating during off peak times only; the designer would specify the storage required with SUN 28 heat exchanger.