Measured Cooling Season Results Relating the Impact of Mechanical Ventilation on Energy, Comfort, and Indoor Air Quality in Humid Climates

摘要

In Florida, residential whole house mechanical ventilation is not required by code andrnmarket penetration of ASHRAE 62.2 compliant mechanical ventilation systems is poor. There isrnconcern amongst regional builders and contractors around implications of mechanicallyrnintroducing humid outside air compared to the indoor air quality benefits, which many feel arernnot adequately documented or demonstrated. These implications include impact on energy use,rncomfort, durability, and cost. This paper describes results from a study in Gainesville, FLrnrelating the impact of ventilation on these parameters.rnTen homes built and occupied in the 2009-2010 timeframe with HERS Index < 65 havernbeen under evaluation since June 2013. All ten homes were built with a central fan integratedrnsupply ventilation system (CFIS) delivering an average of 35 cubic feet per minute (cfm) ofrnoutside air during heating/cooling operation only, and average 3.6 ACH50. As part of this study,rna bathroom exhaust fan in each home was replaced with a larger capacity fan capable ofrnexhausting a continuous 60 cfm on average, approximating ASHRAE 62.2-2010 requirements.rnThe homes were divided into two cohorts: 6 homes that alternate between the CFIS ventilationrnsystem and the continuous exhaust ventilation system every 2 weeks, and 4 homes that operaternone of the ventilation systems exclusively (2 homes per system). Monitoring of temperature,rnrelative humidity, CO2 concentration, and space conditioning energy use occurs continuously,rnwhile concentrations of formaldehyde, acetaldehyde, TVOC, and NO2 are measured seasonally.rnResults spanning late June through mid-October 2013 are presented and discussed.