Free Cooling Coolers
Guntner free cooling units give the opportunity to reduce power consumption and CO2 emissions by substituting chillers systems or similar in low ambient conditions.
A number of clients now utilise the product, where depending on the design parameters, can see the primary cooling plant switched off for up to four months. Equally when heat rejection can not be done exclusively by the cooler, and the primary cooling plant is switched on, the cooler can still contribute to reducing the compressor run hours by providing partial cooling with the chiller 'trimming' the temperature to the desired leaving water temperature.
For example if we consider a close control system serving a switch-data centre
- 90kW total cooling with power input of 30kW
- Maintain room temperature of 24°C +/-2°C
- Resulting that in a 15°C ambient or above 120kW is rejected to dry cooler
- Design conditions are 35°C external temperature & 48°C glycol mix cooled to 40°C
| Ambient | Reduction in compressor hours | Saving in hours PA |
| 10-12°C | 10% | 95 |
| 8-10°C | 25% | 275 |
| Below 8°C | 100% | 2015 |
2385 hours saved per year!
How much do we save?
| Total energy saved | = 30kW x 2385 hours PA | = 71550 kWh |
| Estimated cost saving | = 71550 kWh x £0.12/kWh* | = £8586 PA |
| Power used by fans | = 2 x 1.5 | = 3kW |
| Energy used by fans | = 3 x 2385 | = 7155kWh |
| Cost of running fans | = 7155 x 0.12 | = £858 |
| Money saved | = 8586 - 858 | = £7728 |
| Dry cooler & panel | = £5000** | |
| DX Close control unit | = £10000** | |
| Payback | = (£10000 + £5000) / £7728 | = Less than 2 years |
* Typical conservative electricity cost used
** Typical units prices (2008)
The ECA Scheme
The Guntner range of products also qualify under the ECA Scheme. (www.eca.gov.uk/etl).
"A business that spends £100,000 on designated energy-saving equipment can deduct £100,000 from their taxable profits of the period in which the spending is incurred.
Expenditure on the provision of plant and machinery can include not only the actual costs of buying the equipment, but other direct costs such as the transport of the equipment to site, and the direct costs of installation."
HM Revenue & Customs