﻿Star Refrigeration launches heat-pump system to cool spaces and generate DHW
Star Refrigeration has developed a heat-pump system that can generate chilled water for air-conditioning systems and ‘free’ domestic hot water at up to about 70°C. Called Envitherm, it uses carbon dioxide as the refrigerant and transcritical CO2 compression to produce high-grade heat that can raise the temperature of cold mains water to over 70°C in a single pass. Applications include buildings with a high demand for heating and hot water, such as hotels.
Star’s director of innovation Dave Pearson says, ‘With rising energy costs in the HVAC market, heat pumps are becoming an increasingly attractive proposition for the building-services industry. Utilising waste heat from air conditioning for useful heating can help cut operating costs and reduce carbon footprint. The system may also be eligible for Renewable Heat Incentives.
‘When configured to continuously deliver hot water, the initial capital cost of Envitherm will be recovered in less than three years from energy cost savings. With current carbon-reduction funding incentives, the return on investment will typically be under two years.’
Envitherm is designed for ease of installation, with simple pipework connection to chilled and hot-water circuits and electrics. Units are prewired and come complete with an integral electrical starter panel.
Each unit has a cooling capacity of 34 kW and a water-heating capacity of 45 kW. Multiple units can be linked to achieve higher capacities.
When chilling water from 12 to 7°C, the EER is 3.1 The COP for heating water from 15 to 60°C is 4.1. The overall COP for combined heating and cooling is in excess of 7. With typical utility rates for gas and electricity, each unit will save over £13 000 a year.