Saturday 7 October 2023

Reader Response - HVAC system Draft 3

The webpage “Indoor Farming and Industrial HVAC'' from Metrexvalve (2021) introduces the Heating Ventilation and Air Conditioning (HVAC) units, used in Controlled Environment Agriculture (CEA) for climate control, an important component in the creating and maintaining of a conducive environment for plant growth, the HVAC unit may include dehumidifiers, humidifiers, ventilation systems, exhaust fans, extensive ductwork, ductless air-rotation systems, etc. Due to limited land resources and a heavy population density, Singapore had a heavy reliance on overseas imports for their food supply, up to 90%, this coupled with the supply chain disruptions due to conflicts and pandemics, highlighted the need for Singapore to develop its own reliable and eco-resilient farming modules (Willian et al., 2022). Leading to Singapore's goal of “30  by 30”, to increase Singapore’s agri-food industries capability to produce 30% of their nutritional needs by 2030, local farmers are turning towards technology and innovation to meet its goal as stated by Singapore Food Agency (SFA, n.d.). HVAC units enhance agricultural production, with the added benefit of allowing growth of non-native crops, further improving the food security for Singapore.


A feature of HVAC units is control over the air-conditioning and airflow in an indoor farm, which can provide a constant stream of carbon dioxide enriched air to further advance plant growth and development, as well as maintaining temperatures at specific levels to optimize the growth rate of plants (Benke and Tomkins, 2017). This provides a key advantage over conventional farming methods, as climate change worsens extreme weather conditions, it is likely to disrupt conventional farming at a global scale. CEAs largely separate the production from the natural environment, reducing production disruptions, while optimizing crop production (Cowan, at el.,2022). Thus, the shift towards indoor farms and their developments of HVAC units are so important to countries with food security issues and limited land for agriculture as there is much more agricultural production as compared to conventional farming, providing food security for places like Singapore.


The ability to control the farm's environment also provides an additional benefit of allowing us to grow non-native crops. This is perfect for a country such as Singapore as it is a rather temperate climate, making it hard or impossible to grow more temperamental crops such as strawberries, etc., and so with the ability to control the airflow and temperature, we will be able to grow seasonal produce all year round further helping to bolster food production. Moreover, producing these non-native crops further reduces the ecological footprint that comes with transportation, logistics and even food waste (Kriwangko, 2018).


This is however a caveat to this increase in production of crops, the cost. The switch from conventional to CEA farming requires a large initial investment in infrastructure, and depending on the scale of the projected CEA farm, the cost can exceed millions of USD (Cowan, at el., 2022). Coupled with the cost of maintenance and day to day operations of HVAC units, in extreme climates and northern latitudes, HVAC systems account for 70-85% of the total operation costs, even in warmer climates the cost of a HVAC can still represent up to 50% of the entire CEA operation cost(Engler, at el., .2021). Even though environmental factors are largely reduced, however the ambient environment still plays a part as it affects the energy consumption levels required to maintain optimal growth conditions for crops. A good display of this is from the same article (Engler, at el., .2021) where some studies showed due to a sensor error, a higher temperature was maintained for the indoor environment than reported, that lead to an increase in crops yield, however the additional cost of operations and maintenance greatly overshadowed the increase in yield of crops. Consideration needs to be made to plan for the best growth to energy consumption ratio for optimal results.

 

As it stands, CEAs in general are still economically unfeasible in certain system such as on production of staple crops and meat, and even though HVAC units can greatly bolster the production of crops, consideration need to be made for optimal conditions, not just in regards to greatest crop yield, but also its relation to energy consumption. However it is the technological advances likely to come in the next few decades that makes this a promising solution to the issue with global food shortages. Through constant developments CEAs have already reached the threshold in which renewable energy can be used, further improving the sustainability of food production. With further developments in CEAs and HVAC units due to climate changes increasing effects on conventional farms, these technologies will eventually enable cheap and intensive production of staple foods, thereby showing the true potential of these systems(Cowan, at el., 2022).


References:


Cowan N, Ferrier L, Spears B, Drewer J, Reay D and Skiba U (2022) CEA Systems: the Means to Achieve Future Food Security and Environmental Sustainability? Front. Sustain. Food Syst. 6:891256. 

https://doi.org/10.3389/fsufs.2022.891256


Industrial HVAC (2021) Indoor Farming and Industrial HVAC

https://www.metrexvalve.com/blog/industrial-hvac-for-indoor-farming-and-greenhouses 


Kurt Benke & Bruce Tomkins (2017) Future food-production systems:

vertical farming and controlled-environment agriculture, Sustainability: Science, Practice and

Policy, 13:1, 13-26, DOI:

https://doi.org/10.1080/15487733.2017.139405 


Lisa Kriwangko (2018) Sustenir sows the seeds of success

https://www.businesstimes.com.sg/companies-markets/leaders-transformation/sustenir-sows-seeds-success 


Nicholas Engler, Moncef Krarti (2021) Review of energy efficiency in controlled environment agriculture, Renewable and Sustainable Energy Reviews, Volume 141, 110786, ISSN 1364-0321,

https://doi.org/10.1016/j.rser.2021.110786


SFA(n.d.) 30 by 30, Strengthening our food security

https://www.ourfoodfuture.gov.sg/30by30/ 


William, Y. E., An, H., Chien, S.-C., Soh, C. B., Ang, B. T. W., Ishida, T., Kobayashi, H., et al. (2022). Urban-Metabolic Farming Modules on Rooftops for Eco-Resilient Farmscape. Sustainability, 14(24), 16885. MDPI AG. 

http://dx.doi.org/10.3390/su142416885 


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Reader Response - HVAC system Draft 3

The webpage “Indoor Farming and Industrial HVAC'' from Metrexvalve (2021) introduces the Heating Ventilation and Air Conditioning (H...