Acronyms and initials (let's call that AI,† for short, not to be confused with the other AI, which stands for artificial intelligence, or AIA, which stands for American Institute of Architects) are part of the jargon of every field. Our field, whether you call it building science, green building, home performance, or something else, is no exception. So, a few years ago I started putting together a list that I now include in the manuals that we give out in our training classing (HERS rater and BPI Building Analyst).
I'm up to 117 total lines in my list, which our students find very helpful in sorting out all the jargon that's new to them. When you first come into this field and start getting the barrage of ACH50, HVAC, COP, HDD, WRB, and more thrown at you, it's good to have somewhere to look these things up.
Also, if two AI have the same definition, I included them on the same line. For example, SHR and SHF both refer to the same quantity, even though one uses the word fraction and the other ratio. When a single AI has two different definitions, however, I put them on separate lines. The only one I have like that right now is CO, which could stand for carbon monoxide or certificate of occupancy.
Anyway, I'm sure you're dying to find out what RTFM stands for, so let's get on with it. Below is a table of my top 50 acronyms and initials. If you want the full list, see my instructions below the table.
|AI||What it stands for||URL|
|ACCA||Air Conditioning Contractors of America||acca.org|
|ACH50||Air Changes per Hour at 50 Pascals|
|AFUE||Annualized Fuel Utilization Efficiency|
|AHRI||Air Conditioning, Heating, and Refrigeration Institute||ahrinet.org|
|ASHRAE||American Society of Heating Refrigerating & Air conditioning Engineers||ashrae.org|
|BAS||building airflow standard|
|BPI||Building Performance Institute||bpi.org|
|BTU||British Thermal Unit|
|CCF||hundred cubic feet|
|CFA||conditioned floor area|
|CFL||compact fluorescent light|
|cfm50||cubic feet per minute at 50 Pascals|
|COP||coefficient of performance|
|EER||energy efficiency ratio|
|ERV||energy recovery ventilator|
|GSHP||ground-source heat pump|
|HDD||heating degree days|
|HERS||home energy rating system|
|HPwES||Home Performance with ENERGY STAR program|
|HRV||heat recovery ventilator|
|HSPF||heating season performance factor|
|HVAC||heating, ventilating, and air conditioning|
|IAQ||indoor air quality|
|ICC||International Code Council||iccsafe.org|
|ICF||insulated concrete form|
|IECC||International Energy Conservation Code|
|LED||light emitting diode|
|LEED||Leadership in Energy & Environmental Design|
|MERV||minimum efficiency reporting value|
|NAHB||National Association of Home Builders||nahb.org|
|NZEH||net zero energy home|
|OSB||oriented strand board|
|PTAC||packaged terminal air conditioner|
|QAD||Quality Assurance Designee|
|RESNET||Residential Energy Services Network||resnet.us|
|RTFM||read the friendly manual|
|SEER||seasonal energy efficiency ratio|
|sfbe||square footage of building enclosure|
|SHF or SHR||sensible heat fraction or sensible heat ratio|
|SHGC||solar heat gain coefficient|
|SIP||structural insulated panel|
|SPF||spray polyurethane foam|
|SWAG||scientific wild-ass guess|
|WRB||weather resistive barrier or water resistant barrier|
|wrt||with respect to|
I apologize for not giving definitions and discussions of all of the AI above, but the purpose of this list is just for people to decode the letters when they hear or read them. Perhaps I'll turn it into a full glossary some day.
If you'd like the expanded list of what is currently 107 acronyms and initials, go here:
You can choose to get it as either MS Excel spreadsheet or as a pdf file.
I hope you find this list useful. If you're relatively new to the field, it can be quite handy. If you've been in the field for a while, you probably know all or most of what's here, but maybe you have some others that you think I should add. Let me know.
In the meantime, maybe we can start a battle of the Acronyms versus the Initials! On one side, we'd have RESNET, ASHRAE, PHIUS, and ACCA. On the other, BPI, IECC, AHRI, and ASTM. Whaddaya say?
† AI isn't an acronym because if you tried to say it, someone might dial 911. To be an acronym, it'd have to make a nice word-like sound. Something like IMP (Insulation Manufacturers and Partners) or LUST (leaking underground storage tank), for example. (Only one of those is something I made up, btw.) AI isn't an abbreviation either, which is usually a shortened version of a single word. And don't get me started on contractions! No, AI is a set of initials, which is usually the word people should use when they call something an acronym.
Image of letters by tikitoy998 from flickr.com, used under a Creative Commons license.