Integrated Ventilation Design

By Tom Machinchick

There is, however, an inexpensive and effective solution that can tackle both efficiency and ventilation safety while actually reducing construction costs for a typical project.

Integrated ventilation is a hybrid concrete and HVAC smart floor system that reduces building energy consumption while providing exceptional ventilation safety. Integrated Ventilation feeds air through ducts created in the hollow core (or cast in place) concrete floors to take immediate and full advantage of the thermal properties of concrete.

Integrated ventilation design combines four systems into one: heating, cooling, fresh air ventilation, and thermal energy storage. When the concrete structure of a building is paired with the heating and cooling system of a building, energy consumption reductions of 40%+ can be achieved with no moving parts, no new equipment, and no complex software applications.

Conditioning the temperature of the concrete floors with outside air at strategic times during the day and night using simple fan motors allows this system to maintain comfort levels in the building without utilizing the heating or cooling elements of the HVAC system itself. This is extremely energy efficient, and illustrates the thermal power of concrete when used as part of the ventilation system.

Most of the year, integrated ventilation operates as a dedicated outdoor air system (DOAS) - bringing fresh air indoors, while maintaining the highest standards of air quality and occupant comfort. Recirculation of stale air is rarely necessary, preventing sick building syndrome and the potential spread of infectious diseases such as the recent COVID pandemic. Year-round, non-hydronic radiant comfort provides the best occupant experience.

Integrated ventilation is enabled by this simple L-shaped duct (picture to the right) that connects the flooring system with the HVAC system. There are no moving parts, and no new pieces of equipment to install. In fact, buildings with integrated ventilation look largely the same as any standard building, except for the fact that many of the mechanical systems, including the HVAC system, can be reduced in size or eliminated. Integrated ventilation costs from $10 - $50 per square foot less than standard buildings of the same design, mainly due to these reductions and eliminations.

Ventilation safety and energy efficiency have become high priorities for many stakeholders in the building industry. These can be, but don’t have to be, mutually exclusive goals. Utilizing the building structure as part of the ventilation system of a building helps to increase energy efficiency and ventilation safety, while also reducing upfront and ongoing costs.

Left: Conditioning the temperature of precast concrete hollowcore floor slabs with outside air using simple fan motors maintains comfort levels in the building without utilizing the heating or cooling elements of the HVAC system itself. Right: Simple L-shaped ducts connect the flooring system with the HVAC system.