Reductions in Energy Consumption and CO2 Emissions for Greenhouses Heated with Heat Pumps

Tong, Yen Wah; Kozai, Toyoki; Nishioka, Nobuyasu; Ohyama, Katsumi

doi:10.13031/2013.41488

Cited by 29 publications

(17 citation statements)

References 22 publications

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“…Heating is used as temperature control in winter, thereby increasing energy costs due to greater fuel use, which is highly detrimental to farmers. The application of chilling-tolerant cultivars (van der Ploeg et al, 2007), solar heat collection (Fang et al, 2015;Joudi and Farhan, 2014), heat-pumps (Tong et al, 2012;Zhou et al, 2016), thermal screens (Giacomelli and Roberts, 1993;Kawashima, 2015), water thermal screen systems (Ogura and Mukai, 1988), and split-night temperature (Gent et al, 1979;Toki, 1970) have been proposed as methods for saving energy. Local heating is also an efficient energy saving technique.…”

Section: Introductionmentioning

confidence: 99%

Local Temperature Control in Greenhouse Vegetable Production

Kawasaki

Yoneda

2019

Hortic J

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Uniform temperature throughout a greenhouse is recommended, as the present climate control method and many other studies have shown that the temperature gradient decreases vertically and horizontally in a greenhouse. However, recent research revealed that roots, fruits, flowers, and shoot-tips are more sensitive to temperature changes than leaves and stems, indicating that uniform temperature control may not be necessary. In addition, energy-saving techniques that do not lead to yield loss are desirable to reduce energy costs and ensure sustainable greenhouse production. In this paper, we review current studies on local temperature control methods in greenhouse vegetable production, primarily focusing on the tomato, and compare them with novel climate-control techniques. Roots, fruits, shoot-tips, and flowers are sensitive to temperature changes, showing negative symptoms under extreme temperature conditions. Therefore, the temperature of these plant organs should be controlled locally. Root zone temperature control enhances root growth and its associated physiological activities, promoting uptake of water and mineral nutrients. This subsequently leads to enhanced growth of shoots. Fruit temperature control may not be effective for tomato plants, but it promotes fruit growth and fruit sugar accumulation in melons and watermelons. Shoot-tip temperature control promotes the differentiation of leaf and flower buds. Flower temperature control enhances pollen viability and promotes fruit set. The combination of shoot-tip and flower heating enables low energy consumption compared with conventional heating, without loss of yield. Local temperature control techniques (except roots) have been studied in recent years; however, there is a distinct lack of research on the physiological mechanisms and practical approaches to develop a better local temperature control system. Thus, further studies are required on this area in the future.

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Section: Introductionmentioning

confidence: 99%

Local Temperature Control in Greenhouse Vegetable Production

Kawasaki

Yoneda

2019

Hortic J

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“…Tong et al carried out an experiment in Japan and reported that the hourly energy consumption for heating from January to March in the greenhouse with heat pumps was in the range of 0.22 to 0.56 MJ m −2 , while heating with a kerosene heater was in the range of 0.42-0.76 MJ m −2 . As well, the hourly CO2 emissions in the greenhouse with heat pumps were in the range of 9.5-24 g m −2 , while that in the greenhouse with the kerosene heater was in the range of 31-55 g m −2 [7].…”

Section: Introductionmentioning

confidence: 88%

A Prospect on Integration of Solar Technology to Modern Greenhouses

Koçar¹,

Eryaşar²,

Gödekmerdan³

et al. 2018

deufmd

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The demand for food products is increasing with the growing world population day by day. Given the environmental and land deterioration, agricultural requirement cannot be supply with conventional agriculture. At this point modern greenhouses are attractive alternatives. The high energy consumption of greenhouse systems is a major obstacle to sustainable production. With integration of solar technology to modern greenhouses is aimed to reduce dependence on fossil fuels and expanding the greenhouse in places where greenhouse activities are not carried out. In this study, the current state of solar technology applied in the modern greenhouses has been examined. This study reviews the modern solar greenhouse application technologies which are mainly renewable and sustainable based solutions such as photovoltaic (PV) modules, CSP and hybrid PV/T system. Also, it is summarized what purpose these technologies are used for in the greenhouse. In addition, advantages of solar technology applied to modern greenhouses have been determined.

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“…As a result, in warm climates, the energy used by these systems for air conditioning can be a significant component of the total energy input. Various researchers have evaluated use of heat pumps for greenhouse heating [125][126][127][128][129][130].…”

Section: Heat-pump Cooling Systemsmentioning

confidence: 99%

“…Although the results of these studies were largely positive and demonstrate a potential for cooling glasshouses during sunny periods, the reduction in temperature and RH may not be conducive to plant growth at certain growth stages. Thus, to create a microclimate suitable for plants at different growth stages, complementary cooling methods, such as fogging, evaporative cooling and natural ventilation, could be used in conjunction with a GHE [25,128,147]. A few researchers have pointed out the importance of estimating the undisturbed ground temperature of areas surrounding the greenhouses, given the spatial variation of deep soil temperatures [25,132,144].…”

Section: Geothermal Cooling Systemsmentioning

confidence: 99%

Protected Cropping in Warm Climates: A Review of Humidity Control and Cooling Methods

2019

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The projected increase of the world’s population, coupled with the shrinking area of arable land required to meet future food demands, is building pressure on Earth’s finite agricultural resources. As an alternative to conventional farming methods, crops can be grown in protected environments, such as traditional greenhouses or the more modern plant factories. These are usually more productive and use resources more efficiently than conventional farming and are now receiving much attention—especially in urban and peri-urban areas. Traditionally, protected cropping has been predominantly practised in temperate climates, but interest is rapidly rising in hot, arid areas and humid, tropical regions. However, maintaining suitable climatic conditions inside protected cropping structures in warm climates—where warm is defined as equivalent to climatic conditions that require cooling—is challenging and requires different approaches from those used in temperate conditions. In this paper, we review the benefits of protected cropping in warm climates, as well as the technologies available for maintaining a controlled growing environment in these regions. In addition to providing a summary of active cooling methods, this study summarises photovoltaic (PV)-based shading methods used for passive cooling of greenhouses. Additionally, we also summarise the current humidity-control techniques used in the protected cropping industry and identify future research opportunities in this area. The review includes a list of optimum growing conditions for a range of crop species suited to protected cropping in warm climates.

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Reductions in Energy Consumption and CO2 Emissions for Greenhouses Heated with Heat Pumps

Cited by 29 publications

References 22 publications

Local Temperature Control in Greenhouse Vegetable Production

Local Temperature Control in Greenhouse Vegetable Production

A Prospect on Integration of Solar Technology to Modern Greenhouses

Protected Cropping in Warm Climates: A Review of Humidity Control and Cooling Methods

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