Building Soffits in the Lower Level
We really don’t like soffits.
Why Soffits?
We need soffits in the lower level so we can do the following:
1. Insulate our exposed steel beams that span the exterior stair well and exterior window well.
2. Create space for air ducts for our diplacement air ventilation and allow ventilation in the bathrooms.
3. Define the Wine Dining and Wine Cellar as different spaces from the remainder of the house.
Insulating Our Exposed Steel Beams
The steel beams are exposed to the exterior in order to allow as much natural light into the lower level. However, the steel beams will also allow energy to leave the house in the winter/night and enter the house during the summer/day.
By using soffits, we will be able to insulate the steel beams while keeping the beams exposed.
Creating Space for Air Ducts
Our displacement ventilation requires moving air at very low velocities into each room in a continuous stream, creating a laminar flow that will move stale air into the Atrium where it will rise and exit the house at roof level.
In order to move air into each room, we need air ducts. Since the floor is relatively thin with no joists, we need to have some soffits. These soffits will go around the perimeter of the lower level and, where possible, be hidden by cupboards and wall units.
Defining the Wine Dining and Wine Cellar
The rooms in the lower level have a finished ceiling height of 9 ft 6 inches. To define the Wine Dining and Wine Cellar to be separate and different from the other rooms, we are dropping the ceiling to 8 ft 6 inches. This dropped ceiling will allow ducing to be in the void above the dropped ceiling and enable us to insulate the Wine Dining and Wine Cellar from the conditioned space in the rest of the how.
The dropped ceiling will extend from the Wine Dining two feet into the Wine Cellar, then the ceiling will extend to the full 9 ft 6 inch height. We will have aluminum panels in this space that will receive the cool water (54 degrees Fahrenheit) from our geothermal heat exchange and keep the Wine Cellar at 57 degrees Fahrenheit.
The soffit in the Snack Area will have cupboards below it, which will help to hide the soffit. This soffit will house some can lights, which will provide task lighting in this area.
The soffit changes dimensions and allows us to insulate the interior side of the steel beam, while leaving it exposed on the exterior.
The soffit continues into the Guest Suite, allowing the full beam to be insulated.
We will drop the deiling in the bathroom areas by six inches so the ducting can go through this area easily and we can have exhaust vents to the exterior.
We need to have a hole in this W14x43 steel beam for the air duct to pass through.
And, we will need a matching hole in this beam too. There will be a soffit that will cover the air duct. This is where we plan to have the 'moving wall' that will have contain cabinets for Nik and Kate to store toys and other items.
Soffit in the back of the Pantry, which will bring cool air from the Wine Cellar into the Pantry and allow circulation around the entire house.
The 2x6s in the bearing wall that support the W14x43 steel beam have bowed. Shane Lothrop, from Innovative Structural Engineering, explained that sistering additional 2x6 studs and providing blocking will add structural strength that will address this condition.
Tags: Insulation, Soffits
