Abrasion resistance can either be classified as an object being able to resist wear & tear caused by friction or as a rating. For example ceramic tiles may fall under 1 one of 6 classes; 0 = just looking at it can cause issues / best used on walls 1 = also best used on […]
AC
AC is shorthand for either a) electrical meaning Alternating Current or b) short for Air Conditioner or Air Conditioning
ACH
ACH or Air Changes per Hour refers to how many times that the air in a given space is exchanged per hour. In the Energy Efficiency & Testing arena it is a standardized measurement calculated using a calibrated blower door. While the numbers are straight forward, interrupting the results can be very misleading. Related Article
ACH50
The ACH50 a measure used to determine how “leaky” a house is using a blower door by depressurizing or pressurizing the house by 50 Pa (Pascals) with respect to the outside. In order to get the ACH or Air Changes per Hour number you simply multiply the CFM number required to keep it at 50 by 60 and […]
ACHn
ACHn is short for Air Changes per Hour Natural. One of the biggest issues seen by many is that when one uses a blower door to determine how “leaky” a house is, they are applying artificial conditions that one would not see normally. In order to get ACHn you simply take your ACH50 number & divide it by the LBL factor. The […]
Adjusted Volume
The Adjusted Volume is a means of determining the energy efficiency of a regular refrigerator / freezer combo. As a freezer is colder than a refrigerator and yet they use the same condenser, etc… they have to account for the additional power required. they do this by bumping up the overall volume of the appliance. ENERGY […]
AFUE
AFUE or Annual Fuel Utilization Efficiency, is a rating applied to how efficient a combustion appliance uses it’s main fuel source. This applies to boilers, water heaters & furnaces that burn gas, propane, or oil. In short for every dollar you spend, that amount is actually going to heat your place. For example, a 78 AFUE essentially […]
AHJ
AHJ is generally short for “Authority(s) Having Jurisdiction” – which in most locales is shorthand for ones local Building Department or Building Inspector. However, not everyone may have a local “building department” & or they may have other “authorities” or “agencies” that also have some say in the building or remodeling process. Some examples include: State fire marshal […]
Air Barrier
An Air Barrier is a tested component or material that is installed to control the unintended movement of air into and out of a building enclosure. In order to qualify, the tested component should have an air permeance of less than 0.02 L/(s•m2) @ 75 Pa (0.004 cfm/ft2 @ 1.57 lb/ft2) or equivelant to a 1/2 […]
Air Handler
The Air Handler is one of two major portions of an air conditioner system. It is what accepts the incoming air, conditions it, (heating it or cooling it) and then delivers that conditioned air to just one room or to the whole house. In many cases you will find this portion either somewhere inside the house, […]