KEC Fall Snow

It seems too early for winter weather, but sure enough we received our first taste of snow in October.  Its hard to believe that the last snowfall was only 6 months ago at the April groundbreaking ceremony.  Hopefully this is not a sign if what is in store for us this winter.

KEC Earth Duct

An Earth Duct is a design technique that uses natural ventilation to help temper the air.  This helps pre-heat or pre-cool air depending on the season.  For this project there are (2) runs of precast concrete pipe 24" in diameter and approximately 1000' in total length that are installed at least 4' below grade.  One end of the 2 pipes is open to allow fresh air to be drawn in.  The other end of the 2 pipes is connected to a fan that pulls the outside air in through the inlet, underground for 500 feet side by side, and then up into the building where it mixes it with indoor conditioned air.  

The earth duct is designed to provide a 15 degree temperature differential between outside air temperature and the air being delivered to the air handling units.  This pre-conditioned air will require the geothermal heat pumps to “work less” to condition the air that is ultimately supplied to the building for space conditioning than if straight outside air was delivered to the air handling units.  The outside air is mixed with air returning from the building before it is conditioned and delivered back to the building. 

The system was designed through collaboration between, Kohler Ronan, an MEP engineer with a specialization in sustainable design, Atelier Ten a consulting firm with a specialization in sustainable design, and Landtech, an environmental and engineering consulting firm.

Above is a photo where the earth duct enters the building from the site through the foundation wall.  On the other side of the wall, the earth duct continues under the slab and then rises up to mix with the air in the mechanical equipment in the attic before it is delivered to the building.

Above is a photo of the precast concrete pipe which is installed a minimum of 4' below grade.  Air will be drawn in through the top of the precast structures, then through the pipes where the earth will pre-heat or pre-cool the outside air before mixing it with the building air to reduce the amount of work and energy that the building systems need to use.

KEC Week 29

The tower framing and sips panels were prefabricated on the ground and hoisted up to the top of the tower. This approach was taken because it is much easier and safer to construct on the ground than 40 feet in the air.

Steel for the stair towers is complete.  About 60% of the steel on this project is post-consumer recycled and 15% is pre-consumer recycled.  Post consumer recycled means that the steel was originally used for something else, then it was salvaged and melted down and reused for the steel structure of this building.  Pre-consumer means that the manufacturer has some scrap steel as part of their own fabrication process and they melt down their own scrap and reuse it in production of new steel.

Stone veneer has started. The stone is from a local source in Connecticut about 45 miles from the project site.

Exterior vapor barrier Typar is being installed on the wall sheathing and 30# felt vapor retarder is installed on the roof. This prevents moisture from penetrating the exterior wall into the interior space.

Interior load bearing partitions are being framed.

Interior slab grinding is in progress.

The geothermal vault has been installed. This is where all of the piping from the wells is consolidated through a manifold into two larger supply and return lines that enter the building.

The earth duct piping and vaults are being installed.

The hot water piping that heats the greenhouse is being run from the East wing to the greenhouse underground under the courtyard. This hot water is made using a waste oil boiler in the mechanical room which uses recycled vegtable oil.

Next month the metal roofing, siding, and windows will start on the exterior and mechanical and electrical wiring and piping will start inside.