Senior Research Engineer National Renewable Energy Laboratory (NREL) Littleton, Colorado
An important part of good heating and cooling is distributing air to meet the heating and cooling loads of the rooms in a house. The loads are usually calculated for a specific design load day. Improving home performance involves increasing air sealing and insulation levels of the home, leading to loads that are lower and less need for air volume to condition the home.
This session will discuss air distribution basics and the challenges of delivering the design volumetric flow rate of air at the desired temperature. We will discuss the needs for insulating ducts, both from a thermal and an acoustic performance need. We'll cover getting proper air temperature at the supply, duct surface temperature above the dew point in cooling mode, reduced heat gain and heat loss through the duct, and the factors that lead to good air flow. We will also discuss types of insulation, as well as buried ducts, reflective insulation, and code requirements.
Learning Objectives:
By attending this session, attendees will:
Identify the thermal and flow requirements of air ducts
Understand the mechanisms involved in air distribution and the important parameters that need to be controlled in air distribution systems
Become familiar with the code requirements for insulation in ducts
