Tyvek® ThermaWrap™ LE* Increase Wall System R-Value And Improve Energy Efficiency
A low emissivity, metallized weather barrier that can actually increase the effective R-value of wall systems, to help improve energy efficiency.
DuPont™ Tyvek® ThermaWrap™ LE is made with a metallized, low-emission (low-e) surface that reflects solar radiation away from the building.
In cold weather, this helps prevent radiant heat loss from within the structure. In warmer weather, Tyvek® ThermaWrap™ LE turns the tables, reflecting warm air out and away from the structure, to help improve air-conditioning efficiency.
In all seasons, that can help make both residential homes and commercial buildings more comfortable, more energy efficient, and less costly to operate.
Helping Block Air Infiltration and Exfiltration
In addition to its ability to help increase the effective R-value of a wall, Tyvek® ThermaWrap™ LE is an excellent vapor permeable air and water barrier, like all Tyvek® materials. But the low-e surface changes the dynamics of radiant heat flow across the entire wall system.
Nearly two-thirds of the total heat lost or gained through the building envelope occurs through radiant heat flow. Tyvek® ThermaWrap™ LE addresses this by helping to dramatically improve the effective R-value of the wall system. Originally designed to improve thermal performance of wall systems in some of the coldest climates of northern Europe, it is also highly effective at reducing heat gain when the weather turns hot.
Improving Energy Efficiency
Radiant heat flow occurs when heat is transferred from a warmer object to a cooler one by electromagnetic waves. These waves do not need to pass through air and they do not require any contact between the two objects. They simply cross empty space in exactly the same way as the heat of the sun, which can be felt even on cold or windy days.
Tyvek® ThermaWrap™ LE incorporates a low-e, metallized surface that changes the radiant heat flow dynamics of the wall system. In winter, it reflects radiant heat back into the wall system. In summer, it reflects outside solar radiation away from the wall system, to reduce unwanted heat gain.
The net effect is an overall increase in the effective R-value to the wall assembly. When properly installed, Tyvek® ThermaWrap™ LE adds an effective R-value (thermal resistance) equal to R-2. In both commercial and residential buildings, this can help reduce energy usage and costs for heating and cooling systems, year-round.
Supporting Sustainable Construction
Tyvek® ThermaWrap™ LE offers the optimal balance of water and air hold-out with vapor permeability, which helps you build more sustainable homes and commercial structures. Like all Tyvek® air and water barriers, Tyvek® ThermaWrap™ LE helps prevent water accumulation inside the wall system by allowing moisture vapor to escape to the outside. In turn, this helps reduce the risk of mold and wood rot, which is important in all climates. With its combination of air and water holdout, vapor permeability, and a low-e surface, Tyvek® ThermaWrap™ LE provides the best of both worlds for helping to manage energy efficiency.
Using DuPont™ Tyvek® ThermaWrap™ LE may help to contribute toward U.S Green Building Council LEED® points in the categories of Energy & Atmosphere, Indoor Environmental Quality, and Innovation in Design.
R Value of Insulation - Maintaining Energy Efficient Insulation
Why is R-value important? How do you determine its true value? Building Science Leader Theresa Weston, PH.D., discusses how to maintain energy efficient insulation. She looks at air movement, surrounding materials and air barriers — and the best way to achieving a specified R-value. She also offers up resources for support and installation.
This animation features Tyvek® ThermaWrap™ installed behind brick facade with minimum 1" airspace. Feature to include attachment of proper brick ties with DuPont™ FlexWrap™ NF, mortar bridging and vent placement.
The course will present the latest developments in radiant heat management in buildings. Three different heat transfer mechanisms in buildings – conduction, convection and radiation – will be reviewed but the main focus will be radiation.
Additional Information (8)
- Building Science Bulletin: DuPont™ Tyvek® ThermaWrap™ LE Bulletin (PDF)
- Brochure: DuPont™ Tyvek® ThermaWrap™ LE (PDF)
- Fact Sheet: DuPont™ Tyvek® ThermaWrap™ LE (PDF)
INFORMATION & IDEAS
*Formerly called DuPont™ Tyvek® ThermaWrap™ and now known as DuPont™ Tyvek® ThermaWrap™LE. This rebranding is intended to place emphasis on the low emissivity (LE) benefits that ThermaWrap™ LE has to offer. The physical properties of the product have not changed.