Chiller technology | Archive Titles

Table 1: Relative efficiency of chiller installations relative efficiency (CoP)
Building size (m²)	3000	7700	11500
Chiller size (kW)	400	1000	1500
Air-cooled screw	2.2–4.	0 2.2–4.	0 2.2–4.0
Water-cooled scroll	3.5	3.5	3.5
Water-cooled screw	4–5, 5-6 part load	4–5, 5–6 part load	4–5, 5–6 part load
Water-cooled centrifugal:
Single compressor	6–7, 8–9 part load	6–7, 8–9 part load	6–7, 8–9 part load
Dual compressor	6–7, 10–11 part load	6–7, 10–11 part load	6–7, 10–11 part load

Table 2: Indicative costs of alternative chiller installations capital cost (£)
Building size (m²)	3000	7700	11,500	30,000
Chiller size (kW)	400	1000	1500	3900
Air-cooled screw	56,000	120,000	160,000	468,000
Water-cooled centrifugal
Chiller	n/a	93,000	117,000	255,000
Condensing system	n/a	94,000	121,000	225,000
Total (£)	n/a	187,000	238,000	480,000
Water-cooled screw
Chiller	50,000	88,000	119,000	270,000
Condensing system	46,000	94,000	121,000	225,000
Total (£)	96,000	182,000	240,000	495,000
Costs are current in first quarter 2006 and based on a central London office development.The rates are for the supply and installation of the chiller plant and include allowances for builders’ work. Allowances for trade discounts, preliminaries and testing and commissioning are excluded. No allowance is made for professional fees or VAT. Operating costs are not included.