VENTURES: Innovation With Evaporation
Recent Western Cape Business News
DEVELOPED and patented in the early 90’s, Protek launched its two-stage evaporative cooling system as an alternative to compressor air conditioning for the industrial and commercial markets in South Africa.
Operating on the principle of evaporative cooling of water applied to pre-cooled ambient air, unit supply air temperatures between 15°C and 20°C can be achieved for the most part of South Africa (excluding the Natal Coast and Lowveld). This allows space temperatures between 23 and 25°C to be achieved and makes the system fully suitable for most commercial applications.
The 40 000 sq m DTI office block in Pretoria has been running at a constant 23°C over the past three years at relative humidities between 55 and 65% with these coolers. This is well within world accepted comfort limits today, says Protek’s Neels Claassen.
For the Cape Peninsula, areas around False Bay would not be suitable. But the rest of the Cape Town metropole would be well suited. Due to the fact that water is evaporated directly into the air, the full energy advantage of the evaporation of water (2 500 kilojoules for each kilogram water evaporated) is obtained as opposed to compressor systems where Eskom has to produce electrical energy at 30 – 35% efficiency, evaporating massive amounts of water to condense the steam circuit to produce electricity.
This is then transported with line losses to the compressor, then converted into compressing the refrigerant, condensing and evaporating the same in the unit´s evaporator to generate cooling.
This second process requires about three times the electrical energy of an evaporative cooling process and evaporates more water in the electricity generation than the evaporative cooling process whilst cooling space.
The two-stage evaporative cooling process is a full fresh air process and has been applied successfully over the last 20 years in many markets in South and Southern Africa including commercial (offices, supermarkets, exhibition halls), industry (automotive, printing works, storage plants, electronics, pharmaceutical) and institutional (universities, churches, jails and libraries). It is also used widely in agricultural (grape exports packaging, poultry and egg, plant nurseries, mushrooms).
Exports are undertaken to mostly our South African neighbours and even as far as Australia and other countries in the southern hemisphere.
Claassen predicts in time to come the limitation of electrical power will force designers to consider two-stage evaporative cooling as a serious contender for energy saving when evaluating the electricity consumption of larger projects and specifically when designing for the Green Star Rating System.
“Whereas winter heating still causes an interesting problem to solve, good designers with creative minds can and have found lower energy solutions to reduce winter heating electricity demands,” Claassen says.
Business News Sector Tags:
Fax 2 Email
Study IT Online
Work from Home