Contents

1.0 Problem Statement2.0 Aim3.0 Objectives4.0 Background: Malaysia’s Profile5.0 Greenhouse 6.0 Solar Cooling7.0 Methodology8.0 Work Status9.0 Expected ResultsReferences

1.0 Problem Statement

• Demand for temperate climate fruits and vegetables has risen over the years (Kamarudin, Bailey & Montero 2002) in Malaysia.

•Local production is incapable of catering for this rising demand (Mat Sharif, Mohammud, Abd Kahar 2006).• Application of greenhouse assisted by solar cooling facility will be an alternative approach to meet this market demand.

• A thorough analysis for implementation is required due to Malaysia’s high rainfall, high relative humidity and high ambient temperature.

2.0 Aim

The Research Investigation aims to identify and select solar cooling technology applicable in greenhouses for temperate climate crop production in Malaysia.3.0 Objectives

• Review available greenhouse design for tropical climate

• Review available solar cooling technologies

• Design greenhouse system based on operating parameters for lettuce and strawberry production for Malaysian weather

• Recommendation

Questions to ask and get answered:

• What is a greenhouse?

• What is solar cooling?

• Why does Malaysia need greenhouse and solar cooling?

• Where can Malaysia apply this technology?

• When can it apply this technology?

• How can it apply this combined technology?

• Who can apply this technology and benefit from it?

4.0 Malaysia’s Profile (A Brief Outlook)

• Climateo Located between 1 and 7o North and 100 and 119o East o Equatorial climate with average

annual rainfall of 150-400cm (Mohd Desa & Rakecha 2006), annual temperature of 27 degC, high humidity of 80% daily solar radiation of 15-20 MJ/m2

• Agricultureo Total land area of 329667 km2

o Only 22% of the land utilised for agriculture (Shamsudin 2004)o Arable land for fruit and vegetable is only 1.4% and forecasted to reach 4610 km2 in the year 2010 (Economic Planning Unit 2005)

Malaysia’s Profile (A Brief Outlook) - continue

• Economy

o Has a population of 27 million with 61% making up middle to upper income group

o Net importer of food products more than RM 16 billion annual imports (Chang 2006) temperate fresh fruits import: RM291 million in 2004 temperate vegetables import : RM576 million annual growth demand for temperate climate fruits (strawberry, rasberry and gooseberry) is 5% annual growth demand for temperate climate vegetables is 7.6% (Chang 2006)

(Note: 1RM = AUD 0.35 (2007))

5.0 Greenhouse

• A structure covered with a transparent or partially transparent material for the purpose of admitting natural light for cultivation and propagation of plants (Nelson 2003).

• Most greenhouses have been developed for winter conditions and colder climates.

• Tropical greenhouses require reflection of solar radiation in the non PAR (photosynthetically active region) to reduce heat gain, and lower absorptance of IR (infra-red) region for the same reason.

• Natural ventilation for relative humidity (RH) and temperature control may not work all the time due to high ambient RH and temperature.

6.0 Solar Cooling Technology

• Solar cooling technology in its modest form had existed since ancient Greek time (Florides et al. 2002).

• The technology uses energy from sun for space cooling.

• Presently, it can be divided into two main categories:

electrical photovoltaic (PV) system solar thermal system

(Saman, Krause & Vajen 2004)

• The thermal system is focused in this research. Thermo-sorption process Thermo-mechanical process (vapour compression)

- continue

•The thermo-sorption: open-cycle or close-cycle absorption process for heat removal and generation of cooling media. • Use of hygroscopic properties of certain chemicals (such as sea salt or alkali metal halides) to absorb moisture from one media and transfers the heat to another media through heat exchange.

•Depending on a closed or open cycle, the result will be chilled water or chilled air.

7.0 Methodology

• Select greenhouse type, solar cooling technology and specific crop cultivation parameters.

• Select a greenhouse size, geometry, material of construction and crop coverage for Malaysian weather.

• Select a case year from available Malaysian meteorological data after data processing using FORTRAN90 and EXCEL.

• Design the system via available components in TRNSYS 16, write other additional equations and run the design using the weather data.

• Design a conventional cooling system greenhouse using TRNSYS 16.

- continue Methodology

• Carry out a financial analysis for the design based on the output for crop specific.

• Carry out a comparative financial analysis for the conventional system based on the output.

• Discussion and conclusion.

8.0 Work status

• Research Model

The model uses single span PE (NIR blocking film) greenhouse with lithium chloride liquid desiccant for dehumidification of inlet air and evaporative pad and fan coolers to obtain inlet greenhouse temperature and relative humidity.

Flat plate solar collector is used to generate hot water for regeneration of dilute salt solution in the regenerator (50-70 degC).

-Continue Work status

Crop’s temperature and relative humidity requirement sets the model criteria (22-26 degC, 60-65% RH).

Input to the model is hourly solar radiation (MJ/m2), hourly ambient temperature, wet bulb temperature and wind speed.

• Other inputs are equipment datasheet for absorber, regenerator and evaporative pad.

• Financial analysis to be concluded after completing simulation.

9.0 Expected Results

• Greenhouse design dimensions and operating outputs.

• Equipment specifics for absorber, evaporator, solar flat plate collector and regenerator.

• Greenhouse temperature and relative humidity for specific crop (strawberry and lettuce) – related to above.

• Financial analysis of solar cooling system

ReferencesASHRAE 2005, in pp. 10.1 -.22.Chang, J 2006, Malaysia Exporter Guide Annual 2006, MY6042, USDA Foreign Agricultural Service.Davies, P 2005, 'A solar cooling system for greenhouse food production in hot climates', Solar Energy, vol. 79, pp. 661-8.Economic Planning Unit 2005, Ninth Malaysia Plan 2006-2010, Prime Minister's Department, Malaysia.Florides, GA, Tassou, SA, Kalogirou, SA & Wrobel, LC 2002, 'Review of solar and low energy cooling technologies for buildings', Renewable and Sustainable Energy Reviews, vol. 6, p. 557–72.Grossman, G 2002, 'Solar-Powered Systems for Cooling, Dehumidification and Air-conditioning', Solar Energy, vol. 72, no. 1, p. 53–62.Kamaruddin, R, Bailey, BJ & Montero, JI 2002, 'A Naturally Ventilated Greenhouse For Temperate Vegetable Production in the Tropics', paper presented to International Symposium on Trop. Subtrop. Greenhouses.Mohd Desa, M & Rakhecha, P 2006, 'Annual Highest Persisting 24-hr Dew Points in Malaysia', paper presented to National Conference – Water for Sustainable Development Towards a Developed Nation by 2020.Mat Sharif, I., C. Mohammud, et al. (2006). SMART Environmental Control System for the Production of Strawberry in Lowland Tropics. Proc. IS on Greenhouses, Environmental Controls & In-house Mechanization for Crop Production in the Tropics and Sub-tropics.Nelson, PV 2003, Greenhouse Operation and Management, 6 edn, Prentice Hall, Upper Saddle River, New Jersey.Saman, W, Krause, M & Vajen, K 2004, 'Solar Cooling Technologies: Current Status and Recent Developments', paper presented to Solar 2004: Life, the Universe and Renewables.Shamsudin, MN 2004, Infrastructure Issues: Implications for the Food andAgricultural System.

Evaporative-cooled greenhouse with solar regenerated liquid desiccant (Davies 2005)

Absorption solar cooling (Grossman 2002; Saman, Krause & Vajen 2004)

Type of Solar Cooling Technology (Saman, Krause & Vajen 2004)

Lean-to Even-span

Ridge-and-furrowUneven-span

Structural type of Greenhouse (Nelson 2003)

Type: Tunnel, Single Span

Source: www.greenhousesolutions.com.au

Type: Sawtooth, Multispan

Source: www.greenhousesolutions.com.au