Renderings courtesy of Landon Bone Baker
Landon Bone Baker
RTM provided MEP/FP engineering design for a new 80,000-square-foot, 4-story, 61-unit independent senior housing residence at Main Street and Village Quarter Road in West Dundee, IL. The building will include a mix of one- and two-bedroom units and common features such as a community room, exercise amenities and outdoor spaces.
RTM coordinated with the owner and architect to provide preliminary research and a cost-benefit analysis to evaluate the option of a geothermal system. After reviewing the information, a hybrid geothermal system will be used, incorporating elements from both geothermal and traditional MEP systems.
The hybrid approach is a cost effective design solution as there is less than 5% of the time when weather reaches extreme temperatures that account for 20-25% of the top heating and cooling loads. With minimal time requiring this extra tonnage/heating, the client can reduce costs by using geothermal wells and utilize the back-up heating and cooling systems that are already in place. Rather than install 100% geothermal systems, which can be costly, the client will benefit from cost savings by blending a traditional system with geothermal design.
The greatest challenge is to design the system cost effectively upon its initial install. The owner requested fan coils throughout the building to reduce noise and compressor energy in comparison to the traditional four-pipe system. In utilizing a two-pipe system, the building is in either cooling or heating mode; there are no dual modes. This creates its own challenges to keep residents comfortable year round. RTM performed a case study and discussed options with our vendor to meet this design request. A special heat exchange chiller was recommended in order to make the system work. This heat exchange chiller will take the typical reverse flow and heat pump compressor out of every unit and instead will install one big reverse flow heat pump to serve the whole building.