We always look for the silver bullet when it comes to energy efficiency. Today we hear a lot about: geothermal heat pumps, solar, straw bale construction, radiant barriers, insulated concrete forms, structural insulated panels, steel framing or other single items that are marketed as the solution for an energy efficient home.
It would be easy if we only had to do one thing to make our homes perfectly efficient. But life isn’t that simple. The “silver bullet” approach would have us installing a very expensive geothermal heat pump; but then connecting it to a duct system that is only 50% efficient, in a home that has insulation that performs at 60% of its rating, and with air infiltration three times what it should be – it’s still impossible to have an energy efficient home.
>The secret of true energy efficiency is that there are “a thousand silver BBs”. We need to do a good job on all of the energy features. Perfection is not necessarily the objective; just responsible work quality – but we need to do that on every item that impacts the energy efficiency of the home – which are hundreds of items. Every piece of building insulation, every duct connection, every supply grille, every exhaust fan, every detail – needs to be designed properly, sized properly, and installed properly – so that every feature provides good whole house performance.
Every component and energy feature in the house needs to work well together as one unified system. This concept is called “House as a System”.
When we construct a house using the “House as a System” concept a wonderful synergy occurs between many energy features. We start with a good shell or thermal envelope. By doing building insulation that performs well, installing the correct windows, and sealing air leaks we are able to reduce the size of the
Starting in the mid ’80’s building performance test equipment started to become available and affordable. As contractors started to use this equipment to test the true installed performance of the energy features in homes they found that there was a large opportunity for improvement in every feature examined – even though the work was done in accordance with building and energy codes. This trend continues today. We are able to find opportunities that can reduce heating/cooling costs as much as 80% in new homes constructed today.
Why
The construction industry operates under the low bid system. So insulation and mechanical contractors (the sub-contractors that install most of the energy features) are asked for two things to work in this industry; to be low bidder, and to pass the building departments inspection. They are never asked to provide a cost effective balance between; initial cost (the bid), operating costs (heating/cooling costs), a comfortable home, low noise levels, good air quality, low maintenance costs, a durable structure, durable mechanical systems, etc. – which is what consumers should be asking for (or would like to get). If insulation and heating contractors were asked to provide this cost effective balance they wouldn’t know how, since they have never been asked to do this. To make things worse these sub-contractors are typically trained by the manufacturers that sell them materials – big corporations whose only goal is to make a profit this quarter – not make homes efficient. For example, you typically don’t hear a sales person from an air conditioner manufacturer telling a contractor, “…if you will seal duct leaks and double insulate the duct system you only need to buy an air conditioner that is half the size.”
More Information and Education
Airsmiths has many consumer resources available for more information and education. Contact us with any questions:
Under normala omständigheter inte kan bära en brudtärna klänning i tre färger – rött, svart, vit, särskilt inte bära svart för att närvara vid bröllopet, särskilt de svarta nätstrumpor. Det bästa klänning kjol brudtärna klänning,
