Indoor Air
Good indoor air quality is essential to the comfort, health and productivity of a building’s occupants. TJEG recognized this need early on and worked to exceed minimum code requirements long before the Green Guide for Healthcare (GGHC) or LEED was made available to the industry. Mounting problems with infection issues documented in the healthcare industry gradually brought this need to the forefront. Through its involvement with the Hospital Building Safety Board, TJEG learned that future code revision would stipulate much higher outdoor air ventilation rates for many functional areas within a hospital.
In light of this, TJEG pioneered the development of a 100% Outside Air Handling System with Heat Recovery System for use in hospital applications. This innovation was first implemented at Davis Tower, a hospital project at U.C. Davis Medical Center, winning a First Place ASHRAE Award in recognition of outstanding achievement in innovative design in the areas of occupant comfort and indoor air quality coupled with energy conservation. TJEG has since utilized this design concept in many other hospital projects.
The key sustainable design features of this concept are as follows:
- Reduced initial cost and operational cost
- Improved indoor air quality and the elimination of the spread of infection through the HVAC system
- Reduced water consumption
- The system is ready to conform to any code-requiring increase in outdoor air ventilation, thus eliminating the costly retrofits necessitated with a traditional return air system
- Reduced material and labor is required for manufacturing and installation, decreasing the first cost as the return ductwork system has been eliminated entirely
- Improved energy efficiency due to the Heat Recovery System with the reduction of the number of running fans. This in turn reduces the size of the mechanical and electrical generation and distribution equipment
This major innovation – 100% Outside Air with Run-Around Heat Recovery works to improve indoor air quality, reduce the spread of infection and at the same time, save first cost and life cycle energy consumption. TJEG improved the efficiency of ventilation and air conditioning systems further by obtaining OSHPD approval of the first hospital Displacement Ventilation System with Reheat. Displacement ventilation improves air quality by improving ventilation efficiency to the space by as much as 20% or more.
