Energy Efficiency Quiz Answers

(3) The basement is one of the largest contributors to heat loss in the average home. Most concrete basement walls in unfinished areas are left uninsulated. If only half of the basement is unfinished, this can represent 35% or more of the total heat loss of the structure. For about $200-300 a special type of foam insulation can be attached to just the top half of the wall that reduces this loss by 60%. In our test home the unfinished area was small and required only 7 sheets of foam board at a cost of $140 installed, yet this resulted in an improvement of 11.1% to the building envelope.

1-1/2" thick Polyisocyanurate Foam Boad


(4) LoE/Argon-filled windows cost an extra $2/s.f. of glass over standard double-pane glass and have 50% more insulating value. The cost for our test home was about $450. This resulted in an 8.3% improvement in the building envelope.

 

LoE/Argon-filled glass


(2) Covering the exterior with R-2.5 boxing was about $1200 on our test home (not including labor). This results in a 7.7% improvement. While using boxing is not as cost effective, it also reduces infiltration, sound transmission, and improves the structure's water shedding ability. The adjacent photo of our test home also shows this boxing placed on the "knee walls" (walls between finished space and the attic). These walls are commonly left unboxed which leaves the back of batt insulation exposed to the attic. However, manufacturers require that batt insulation be placed in an enclosed cavity to yield its rated R-value.

R-2.5 Boxing on exterior walls and knee walls


(1) Ironically, the least effective improvement is the one that is common practice. Increasing the attic insulation to R-40 yields an envelope improvement of only 1.4%. A better improvement is to use blown cellulose insulation instead of blown fiberglass. Several studies have shown that blown fiberglass insulation's R-value is temperature dependent due to convection. When the attic temperature drops to about 15 degrees, the R-value of blown fiberglass drops about 50%, while the cellulose remains unchanged. Cellulose is also safer and better for the environment.

R-40 Blown Cellulose


The answer is to the second question is of course (4). The average home uses as much energy and produces as much greenhouse gas as two automobiles. Answers 1, 2, and 3 all involve some sort of sacrifice, but a more efficient home improves your quality of life by improving the comfort level of your home while saving you money.

One of the reasons conserving energy is so important is that the energy that reaches the consumer is only about 10-20% efficient. This is due to losses at the power plant and transmission line loss. Therefore, for every unit of power one saves, 5-10 units of power is saved at the source in the form of coal.

To learn more about these and many other energy efficient methods being used by Ezell-Morgan, email us or bring us your plans for a free energy analysis.