Cooling and Ventilation Strategies for Fresh Impact Farm

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Project Team
Justin Flaherty
Tom Li
Milan Moise
Hannah Reitzas

Project Sponsor(s)
Ryan Pierce, Founder and CEO, Fresh Impact Farms

Instructor(s)
Dr. Steven Shooter, MAE, GW Engineering

Fresh Impact Farms, an indoor farm in Arlington, Virginia, delivers flavorful, chemical-free, and sustainable produce within a hyper-local supply chain. Using hydroponic systems, the farm cultivates herbs, greens, and edible flowers to meet the demands of chefs for locally grown, premium-quality products. However, achieving these goals presents an energy challenge due to the year-round operation of air conditioning systems. The heat generated by their artificial grow lights exceeds the cooling requirements of their indoor farm, driving high energy consumption and associated costs. To address this challenge, the team is developing a solution that reduces the cooling load on the air handler unit.

Who experiences this problem in the world?

Heating, ventilation, and air conditioning (HVAC) systems are responsible for a significant portion of total building energy consumption, posing a particular challenge for indoor farms. These growing facilities require precise temperature and humidity regulation to ensure proper plant growth, meaning the HVAC systems must run continuously. The need for consistent artificial lighting further adds to the energy consumption burden, ultimately increasing expenses and placing financial strain on farmers seeking to keep operations both efficient and sustainable. Small-scale indoor farms and agricultural initiatives, in particular, face even greater difficulties due to limited access to affordable energy solutions.

Why is this problem important?

Small-scale indoor farms like Fresh Impact Farms play a crucial role in promoting sustainable agriculture and strengthening local food systems. By growing plants in controlled environments, these facilities reduce the need for vast land areas, require significantly less water than traditional farming practices, and minimize long-distance transportation, lowering emissions in the process. Unfortunately, the high prices associated with constantly running both HVAC systems and artificial lighting create a financial strain that can threaten the long-term viability of these farms. Developing and implementing a method to harness ambient air for conditioning controlled environment agriculture spaces has the potential to reduce energy costs to ensure the continued growth of sustainable farming operations.

What is the coolest thing about your project?

This project has a strong local impact. Fresh Impact Farms serves restaurants and businesses throughout the Washington, D.C. area. These are places where students and locals can directly experience the benefits of sustainable indoor farming. With limited research available on natural ventilation in controlled indoor environments, the team's work has the potential to fill a critical knowledge gap. Some of this work includes developing an energy simulation to model airflow, temperature regulation, and energy efficiency within the facility. Additionally, building a small-scale demonstration model to test findings in real time. This approach allows for experimentation with optimizing natural ventilation, reducing energy consumption, and improving overall sustainability in indoor farming. By combining simulation with physical testing, the team hopes to create a scalable solution that could be applied to other indoor farming operations.

What were some technical challenges?

Many facilities with high process loads, such as data centers, implement free cooling solutions to reduce energy costs by using cooler outdoor air instead of mechanical refrigeration. However, free cooling is unsuitable for indoor farms due to an additional consideration: carbon dioxide (CO2) concentrations. Fresh Impact Farms maintains a CO2 concentration of 1200 parts per million, which is approximately three times higher than in ambient air and requires the injection of CO2 into the space. When free cooling and CO2 injections are both used, the cost of the additional CO2 trumps the savings achieved by powering off the compressor. This unique interplay of temperature, humidity, and CO2 management makes cooling indoor farms more challenging than other high-energy facilities.