sealing

For years, ventilation and air-conditioning systems have played an increasingly important role in ensuring sufficient air exchange in buildings. With time buildings are becoming more and more airtight to avoid energy losses through uncontrolled air leakage and mechanical ventilation systems are installed to ensure a good indoor air quality. What is a good approach in theory can fail in practice due to leaky ductwork.

Purpose of the work

Windows according to the Passive House Standard 2016 require a ten times more airtight airtightness class (EN 14351) [1] than around 1990. The installation layer of the windows is constantly moving closer into the area of the insulating layer with possibly moisture-sensitive materials. Therefore, joint sealing of construction and connection joints must also be evaluated by applying parameters related to building physics like thermal conductivity, diffusion behavior, heat and moisture storage capacity, and the capacity for movement absorption.

This paper describes two recent applications of aerosol sealing techniques in buildings for improving indoor air quality and reducing energy required for heating, cooling, and ventilation. One application applies a commercially-available duct sealing technology, which has typically been used in single-family applications, to large-building exhaust systems. The initial leakage rates, percent leakage sealed, and issues encountered are presented for several large buildings.

In air-based systems, ducts deliver heat and cool air to conditioned spaces. Taking extra time to properly seal ducts during the installation along with repairing and patching leaks in HVAC duct systems will save cooling, heating and fan energy. With aerosol-sealing technology higher performance ducts in new and existing buildings potentially exist.

This paper deals with the use of an Air Curtain Device in a typical HVAC application where there is a need to provide aerodynamic sealing between a comfortable human enclosure and a warmer neighbour space.Three different complementary experiments were used in this work : tracer gas method (N2O), Flow field mapping and Infrared thermo-graphic visualizations.The used experimental methods revealed adequate and complementary to understand the flow topology of the studied case

Describes the experimental evaluation of a brick veneer steel stud (BVSS) test specimen. The system was evaluated for air leakage characteristics, pressure equalization response, deflection and water penetration. Concludes that for best results for BVSS walls, the air barrier must be sufficiently airtight to achieve static pressure equalization and there must be sufficient venting to achieve dynamic pressure equalization. Similar results were obtained from research conducted on other wall systems.

No more will weatherization crews find their hands tied when they see opportunities for energy savings in every corner-the Weatherization Plus plan will open the door to bring home advanced technologies.

A building's envelope is the product of the choice of framing materials and quality of craftsmanship. Exposed to weather, it may 1101 provide the same airtight conditions in which its insulation material had been tested. Air permeable insulation offers little resistance to pressure driven, or convective, heat loss. Air impermeable insulators can additionally reduce convective, as well as conductive, heat loss by being sprayed into and sealing up sources of infiltration normally addressed by caulks and sealants.