Installation of wood trusses to support the roof of the headhouse.
Two-inch thick perimeter insulation (approximately 2 feet deep) is installed along the outside walls of the headhouse. This perimeter insulation makes for an effective heat-loss barrier.


Framing of the interior walls for the cold storage room located in the headhouse. Note the yellow fiberglass insulation blankets in the outside walls and the metal clad ceiling. Fiberglass insulation blankets were installed in the attic, just above the metal ceiling panels.


Inside the headhouse (40 feet wide by 96 feet long), a utility room is constructed. Because the boilers would be installed inside this room, the local building code required this room to have a high fire rating. Therefore, the walls of the utility room were constructed from concrete blocks.


Two natural gas fired hot-water boilers (1.2 MBtu/hr input each) were installed in the utility room.


General view of the plant growth room inside the headhouse.
The office area with the environment control computer system.
The finished cold storage room, large enough to hold several days of harvested product.
The main work area inside the headhouse is under construction. The greenhouse is located to the left of this picture.
The washing station inside the headhouse is used for cleaning the Styrofoam™ floaters. A weak bleach solution is applied before the floaters are thoroughly rinsed.


The main entrance door to the facility (facing East) and, to its right, a loading dock with overhead door.
The utilities (electric, gas, water, and phone) were brought into the building from the West wall of the headhouse. Note the weather station (wind direction, wind speed, outside temperature and humidity, and solar radiation) at the ridge of the headhouse.
A (liquid) carbon dioxide tank with refrigeration unit (to the right) is installed along the North wall of the headhouse. The liquid carbon dioxide is vaporized before it is directed to the greenhouse and growth room. Carbon dioxide enrichment is used to increase crop growth.
Liquid oxygen tanks are supplying vaporized oxygen gas to the recirculation nutrient solutions in each of the four ponds. An automatic switching valve (center) is needed to switch from one tank to the other when the first tank runs empty.


Custom-made, water-cooled high-pressure sodium lamp bulb (600-watt). Water is pumped through the outer glass envelope. The operating lamp heats the cooling water as it passes through the bulb. Note the inlet and outlet ports to the sides of the lamp bulb.
Top-view of the installation of a water-cooled high-pressure sodium lamp and reflector located in the growth room. The lamp and reflector are mounted in a two by two feet ceiling panel, which is part of a so-called false ceiling. Note the black hoses bringing cooling water to and from the lamps. The (heavy) luminaire ballast is located several feet away from the lamps and is not supported by the false ceiling.
Operating water cooled lamp
Bottom-view of the installation of a water-cooled high-pressure sodium lamp and reflector in one of the ceiling panels located in the growth room.


A recirculating chiller removes heat from the cooling water and returns it to the water-cooled high-pressure sodium lamps located in the growth room.


A carbon dioxide sensor inside the growth room registers the carbon dioxide concentration. The sensor communicates with the environment control system and the computer operates a solenoid valve in the carbon dioxide supply line. A similar setup is used in the greenhouse to control its carbon dioxide concentration.


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