Development of an integrated ventilation, thermal mass, and lighting system for the first Deep Winter Greenhouse (DWG) in North Dakota

Progress report for FNC20-1234

Project Type: Farmer/Rancher
Funds awarded in 2020: $8,980.00
Projected End Date: 01/31/2022
Grant Recipient: Folly Hill Farm
Region: North Central
State: North Dakota
Project Coordinator:
Derek Lowstuter
Folly Hill Farm
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Project Information

Description of operation:

Folly Hill Farm is a working demonstration farm that was established in late 2016. The farm is situated on 40
acres of pasture land two miles north of the town of Menoken, ND. It is owned and operated by myself, Derek,
and my wife, Claire Lowstuter. We currently live on the property with our daughter, and are looking into
additional housing to host interns, seasonal employees, and agritourism guests. I am the Forest Stewardship
Manager for the NDSU-North Dakota Forest Service. I have a Bachelor’s Degree in Natural Resource
Management and a Master’s Degree in Collaborative Forest Management from Colorado State University. I am a
certified arborist, permaculture designer, and agroforester; with experience designing and managing permaculture
practices in the western U.S., Ireland, Ethiopia and Thailand. Claire has a Bachelor’s Degree in Human
Dimensions of Natural Resources with a minor in Sociology. She is also a certified permaculture designer and
shares the same international agricultural experience. We are Returned Peace Corps Volunteers from Ethiopia.

The farm was established as a trial and demonstration farm for the organic soil amendments produced by Black Bison Organics LLC. The primary purpose of the farm is to be a testing ground for these products. The second, but equally important, purpose of the farm is to demonstrate innovative agricultural practices based on permaculture, agroecology, and agroforestry methods. Folly Hill Farm was established as a small, diversified farm that is intended to be self-supporting through the sale of raw and value-added agricultural products, and on-site trainings. The farm is not self-sufficient yet, but we are working towards that goal. Roughly thirty-five acres of the property are grazed by cattle owned by Paul and Gabe Brown of the neighboring Brown’s Ranch. We currently raise 50 laying ducks of various breeds and sell the eggs through local markets. There are plans to add fiber animals in 2020/2021. We grow various fruits and vegetables that we sell at a local market, and also sell to local CSA producers to supplement their share offerings.

There are a number of small fruit and unique trees that have been planted over the past two years. These include haskap, apricot, plum, rose hip, aronia, and many more.

We received grant funding from the ND Dept. of Agriculture in 2019 to cover some of the cost associated with building the first Deep Winter Greenhouse (DWG) in the state. The building is currently being constructed and will be complete by early spring 2020.


The project will monitor and integrate the active and passive environmental control systems of the first Deep Winter Greenhouse (DWG) built in North Dakota. DWGs are passive-solar structures with angles & dimensions that maximize solar heat during winter months, when the sun is low in the sky, and minimize solar heat during summer months, when the sun is high in the sky. The project will help balance the passive components of the greenhouse, such as the innovative use of phase change materials and an underground climate-battery, with the active components of the greenhouse, such as ventilation, heating, lighting, and CO2 supplementation. Funds will be used to professionally monitor and electronically-integrate the systems so they work synergistically, instead of antagonistically; which can easily occur with these multipart, multistage systems.

This work will maximize the efficiency of the greenhouse for growing specialty crops, and  improve its use as a demonstration and educational facility. Although the function of the greenhouse is to grow crops, its primary purpose is to demonstrate the use of innovative production methods for beginning and established producers. This project will improve the utility of the greenhouse as both an educational and agricultural tool.  

Project Objectives:
  1. Develop a monitoring system and integration protocol to maximize efficiency in, and between,  greenhouse heating/cooling, air exchange, humidity, CO2, and lighting systems. This includes improving the way systems work together, but also mitigating system antagonism (e.g. venting air at same time as pulling heat from thermal mass).   
  2. Evaluate the effectiveness of tiles composed of phase change material in regulating the internal temperature of a passive solar greenhouse, reflecting ambient light, and acting as a durable greenhouse wall covering.
  3. Evaluate the effectiveness of a Ground to Air Heat Transfer (GAHT) system in heating, cooling, and dehumidifying a passive solar greenhouse in North Dakota.


Click linked name(s) to expand
  • Stephanie Blumhagen (Educator)


Materials and methods:
This is the final design used to construct the greenhouse. The brown panels are below grade and the grey panels are above grade.

No SARE funds will be used on construction of the greenhouse - only on the monitoring and control systems, and the experimental phase change material.

The greenhouse was designed and built using well-established passive-solar principles. The materials used in the greenhouse and its systems were selected for their appropriateness in this application, including cost. The combination of active and passive environmental control systems with an integrated sensor network will allow us to see how well the systems are working independently and together. The Monnit sensor network and data gateway are designed for greenhouse applications and is composed of a light sensor, humidity sensor, CO2 sensor, and temperature sensors throughout the greenhouse and in the underground thermal/climate battery (GAHT system).  GAHT (Ground-to-Air Heat Transfer) is a trademark of Ceres Greenhouse, which designed the system. The monitoring system will transmit data every 10 minutes, unless condition thresholds are crossed. These data points will allow us to make changes in the environmental control system set-points and draw conclusions regarding the performance of the systems from the resulting sensor data.

The fans, motors, and thermostats used are designed for greenhouses and will improve our ability to manage the environment.

An electrician is needed to effectively, and safely, wire the monitoring and control systems to better control how they operate.

The use of phase change materials as both thermal mass and passive temperature control have tremendous potential in greenhouses; where solar energy must be intercepted, stored, and released. This reduces heating and cooling costs and saves room in the greenhouse that would otherwise be filled with bulkier and less-efficient forms of thermal mass, such as water barrels.


Participation Summary

Educational & Outreach Activities

5 Consultations
1 Webinars / talks / presentations

Participation Summary:

73 Farmers
Education/outreach description:

I have received several calls/ Facebook messages regarding the greenhouse project. I have helped those people answer one-off questions or had lengthy discussions on how the practices could be applied to their own grown operations. Some of the lessons learned on this project are applicable to high tunnels or significantly smaller "hobby" greenhouses.

I joined other agricultural professionals and producers to participate in a Facebook Live webinar on SARE Farmer Rancher Grant project development and application. We shared our projects and experiences with the Farmer Rancher Grant Program. The webinar can be viewed on the FARRMS Facebook page:



Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.