In this post, we will explore the great big world of insulation with you. We will provide what may be surprising answers to questions like: Why do we insulate? How much insulation do you need? How do we know what to do?
There is more to insulation than meets the eye. When most of us think of insulating a home, we think of how well it will retain heat or cooling, or how well it will prevent heat or cooling loss through the building walls, floors and ceilings. While this is important for thermal comfort, insulation is also vital to prevent moisture related issues and sound reverberation.
The psychrometric chart is used by Architects and HVAC designers to understand how the moisture content and temperature of air impact an occupant's comfort. This allows us make informed decisions about designing to accommodate the intended occupant. The Psychrometric Chart is a graphical chart that allows the designer to determine the temperature a space will be perceived as comfortable to its user in various climatic regions. For passive design, understanding the thermal comfort of the occupant can be essential for understanding the effectiveness of natural ventilation and passive heating or cooling strategies. When insulating a house passively or actively, thermal comfort has a direct effect on the insulation quantity and location.
Now that we understand that thermal comfort for an occupant can vary across different environments, we can design homes to meet that requirement. We achieve this by designing to one of two ways, both are regulated and enforced in Washington State by the Washington State Energy Code (WSEC). Both methods utilize a variable to understand thermal transmittance; R-Value or U-Factor.
In either method to achieve the state regulated insulation requirements, we end up with a building that performs to a predetermined standard. Since all buildings are different, we have to get creative with how to achieve this.
Moisture related issues, like condensation, can arise if a building is improperly insulated. The general-of-thumb for insulating a home is a heating heavy (cold climate) region is to put the insulation on the "warm" side of the assembly pack. By assembly pack, we are referring to all of the components that are layered together to create a wall, floor or roof. For Washington State, this translates to putting the bulk of the insulation within the wall cavity.
Acoustics can be a major design challenge in residences. A simple solution can be to put insulation within the interior walls, and add isolation clips for the wall cladding material. The vibrations created from sound on one side of the wall can be reduced by the isolation clips, and absorbed by the insulation before it reaches the other side of the wall.
Acoustical Surfaces, Inc has a helpful webpage about NRC, the rating we use to understand noise reduction. Check out their post here.
Insulation requirements keep becoming more stringent. As Architects, we are challenged to keep up with these requirements while maintaining a spatial and aesthetic beauty.
There is regulation in some states that determines what the insulation values have to be. The west coast states tend to be more progressive with implementing and updating these requirements. As previously mentioned, in WA State we have to abide by the Washington State Energy Code. This code has increasingly strict requirements that impact everything from your home's windows to its roof. Every 3 years these requirements are updated and building assemblies have to change to account for the latest requirements.
Want to learn more? We'd be happy to help, get in touch with us here.
