SUPERIOR INSULATION
NonWoodHouses™ have an inherent advantage when it comes to energy efficiency as compared to conventional wooden frame houses: they have far more effective insulation built right into the structural materials. This eliminates the need for additional logistical and construction operations to obtain and install extra insulation materials, but still provides superior performance. Specifically, a NonWoodHouse™ delivers low thermal conductivity, good air tightness, and high thermal mass: the final result is substantially lower energy usage to maintain desired climate conditions.
THERMAL CONDUCTIVITY
There are many factors to consider when analyzing the energy efficiency of a home design, but the primary attribute is usually the thermal conductivity of the wall systems. These account for the largest surface area and consequently some of the biggest potential for energy flows.
NonWoodHouse’s™ Autoclaved Aerated Concrete (AAC) is an amazing material that delivers much better performance than wall systems commonly used in residential applications in the US. With a lambda value (heat conductivity coefficient) as low as λ = 0.06 W/mK, the effectiveness of AAC as insulation in and of itself is more than twice as good as a typical wood frame insulated wall system!
This material looks like pumice; it is light and floats on water. The actual mineral composition of this sponge-like skeleton is similar to limestone. It is a solid material, manufactured in compliance with the strict European energy performance regulations.
AAC blocks have such low thermal conductivity, they can maintain almost unbelievable temperature profiles across their thicknesses.
AIR TIGHTNESS
There are also other advantages that traditional house construction methods cannot replicate merely by adding more insulation. Wooden frame structures have significant voids and suffer more air infiltration and exfiltration that directly cause thermal energy losses regardless of how effective their insulation is against heat conduction. Attempting to compensate for these vulnerabilities is never perfect and is a laborious process.
A full masonry design, on the other hand, allows for a tight, sealed building envelope that retains air much better. NonWoodHouses™ have no voids like wood frame assemblies do. In addition to the energy benefits this provides, it is also an important element in preventing fires; flames cannot propagate through channels with alarming speed like they can in wood frames. Similarly, insects are denied an access pathway.
Our AAC material has high air content to keep thermal conductivity low – but that air is locked into the material, preventing air flow. The material is, however, permable to vapors, giving the building breathability to provide better air quality.
The differences in performance are dramatic.
A study in Finland compared the rates of air leakage in wood frame buildings against masonry buildings – even those that were not constructed with any kind of specialized air retention features. Masonry envelopes had intrinsically better air retention, usually more than twice as good as typical wood frames.
THERMAL MASS
Masonry buildings have intrinsically higher thermal mass (heat capacity), meaning that they will retain temperature better when exposed to changing ambient conditions. Any dramatic weather changes will be greatly dampened over time, ensuring occupants remain comfortable from the start rather than waiting for heating and cooling systems to engage after becoming uncomfortable.
Furthermore, there is an enlarged transition period between hot and cold seasons when the house requires neither heating nor cooling over the course of an average day to maintain acceptable temperatures.
GREATER COMFORT IN ANY SEASON
A house’s heating or cooling load in a steady state is approximately proportional to the difference between the outside and inside temperatures. As a result, it is a common practice to use lower or higher target temperatures in the winter or summer, respectively, to minimize that difference. This can lead to discomfort for occupants, who may choose to override these targets, thereby negating or even reversing any energy savings. A NonWoodHouse™ delivers a more consistent, comfortable, and efficient experience. Its superior insulation attributes mean that a given heating or cooling load can yield a greater temperature difference, allowing a bigger range of preferences throughout the year.
ENERGY SAVINGS
What does all of this mean for the bottom line? Let’s take a look at the numbers for an actual NonWoodHouse™ occupied by a family.
As you can see on this independent PSE&G analysis of 994 similarly situated homes, this NonWoodHouse™ built in New Jersey is more than twice as efficient as the benchmark “efficient” home as defined by PSE&G, and almost three times as efficient as the actual average home. This means that the energy bill is proportionally smaller!
This NonWoodHouse™ exhibited very low gas usage year-round. Especially notable is that usage was almost nil for significant periods of time while less efficient houses needed to consume substantial amounts of energy.
