Objectives Continue with advance HVAC systems Compare Residential and Commercial Systems - Trends in residential HVAC

Sensible and Enthalpy Wheels

Heat recovery system in NSM building at UT

Desiccant wheel Figure 3 – A desiccant-based cooling system combined with regenerative heat exchanger, vapor compression cooling, and evaporative humidifier (hybrid system).

Review: Computer software for load calculation http://www.xpedio.carrier.com/idc/groups/public/documents/marketing/hap_ehelp_009.pdf http://www.doe2.com/equest/ http://apps1.eere.energy.gov/buildings/tools_directory/subjects.cfm/pagename=subjects/pagename_menu=whole_building_analysis/pagename_submenu=energy_simulation

Review: Residential vs. Commercial systems Course focus was on HVAC equipment that is used in both: residential and commercial systems Emphasize on the application in commercial systems

Commercial HVAC Systems Single zone Multi zone All Hydroinic that relay on infiltration VAV CAV CAV VAV With and without humidity control With and without reheaters Dual duct Dual duct With reheaters DOAS with fan coils DOAS with fan coils or radiant ceilings This is not the complete list ! There is no strict division!

Typical Components in Commercial systems Constant operation Outdoor air supply Two fans (supply and return) Multizone system Control …..

Residential System

Residential system Technology is feasible and cost-effective Several barriers to widespread use: Up-front costs are still higher Insufficient data on resale costs Lack of experienced designers