Passive House Windows
Passive House is the world most forceful building energy conservation standard. This is accomplished through a super insulated envelope, extreme air tightness, and very economical heat recovery ventilation. The home will use 70-90% less energy than a standard home of the same size including the use of energy efficient appliances and lighting.
Source: http://www.rhirvinghomebuilders.com
One of the great advantages of the Passive House standard is that with a great insulated envelope the house will never go below 15 degrees Celsius even without a heating system. Passive solar energy, gathered through the large south windows will maintain the house at a stable temperature and keep the pipes from freezing even if the house is not occupied for long duration of time in the winter.
Windows can create or takeaway a home efficiency and budget if not picked carefully. Windows will be one of the biggest single item costs on the home and super efficient windows require a premium. This premium is validated because standard windows will most likely need that you have more PV panels, or more cords of wood to make up the lost heat. The design of the home should place and size windows in such a way to get most heat gain in the coldest intervals and discard the most heat in the hottest. Old single pane windows take away so much energy and are the cause of chilly drafts, but even dual pane windows are not efficient enough. Passive House standards are quite strict and for a good reason, windows can drain a house of conditioned air very fast.
It makes sense to invest in a high performance triple glazed window, taking into consideration windows often account for upwards of 50% of all energy loss through a building envelope, By investing in high performance windows it enables a home or building designer to minimize the heating system, make the indoor air quality better and benefit from passive solar heating.
There are two main causes which makes having quality windows very vital. One of the reasons is associated to the thermal comfort of the occupants, which is directly influenced by the quality of the windows in the house. The other reason having quality windows are important because it minimizes the energy loss and saves money
High performance triple glazed windows that meet Passive House certification standards are required to have a thermal resistance lower than 0.80 W/(m².K) for both the window and frame. This is over double the thermal resistance rating when compared to a minimum building code rated window. In addition to that, direct and indirect solar gains are collected through the glazing that results in more energy obtained through the windows than what is essentially lost, even during the winter. It is essential for the designer to properly place the windows as well as considering shading and summer/winter sun angles that in return results in vast amount of energy savings.
In the energy saving side, a tripe glazed window get warmer not only at its edges where condensation usually occurs in single and double pane windows but gets warmer over its entire glazes surface. In the Thermal comfort side there would be up to 80% less radiation heat transfer between the glazing and the room .
The window frame has to perform just as well as the triple glazed window unit because the entire assembly, both frame and window, must meet the Passive House window requirement of a thermal resistance lower than 0.80 W/(m².K). The escalation of Passive House design in the last couple of years has now brought certified window frames that are available in wood, vinyl, aluminum, fiberglass as well as many hybrid systems. They all have distinctive qualities in terms of thermal conductivity, dimensional stability, insulated frames, durability and aesthetics but the critical requirement is that they meet the low thermal resistance requirements.
If you are interested in triple pane windows on your next Atlanta custom home or Atlanta home renovation, contact Eco Custom Homes at 404 303 7280 or email to info@ecocustomhomes.com, and we can walk you through the costs as well as what glass specifications are right for your needs.
Resources:
