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 classes.
I’m up to 153 total lines in my list, which our students find 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 you can 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 153 acronyms and initials. If you want to download the list, see the link below the table.
Acronym | What it stands for | |
AAC | autoclaved aerated concrete | |
ABAA | Air Barrier Association of America | |
ACCA | Air Conditioning Contractors of America | |
ACH50 | air changes per hour at 50 Pascals | |
ACHnat | air changes per hour natural | |
ACI | Affordable Comfort Inc. | |
ADA | another damn acronym (although this would really be initials) | |
ADA | Americans with Disabilities Act | |
ADC | Air Distribution Council | |
AFUE | annualized fuel utilization efficiency | |
AGW | above-grade wall | |
AHJ | authority having jurisdiction | |
AHRI | Air Conditioning, Heating, and Refrigeration Institute | |
AHU | air handler unit | |
ANSI | American National Standards Institute | |
APHN | American Passive House Network | |
ASHP | air-source heat pump | |
ASHRAE | Amer. Soc. of Heating, Refrigerating, and Air-conditioning Engineers | |
ASTM | American Society for Testing and Materials | |
BA | Building America | |
BAS | building airflow standard | |
BCAP | Building Codes Assistance Project | |
BOP | Builder Option Package | |
BPI | Building Performance Institute | |
BS | building science | |
BSC | Building Science Corporation | |
BTL | building tightness limit | |
BTU | British Thermal Unit | |
CAZ | combustion appliance zone | |
CCF | hundred cubic feet | |
CDD | cooling degree days | |
CFA | conditioned floor area | |
CFL | compact fluorescent lamp | |
cfm | cubic feet per minute | |
cfm50 | cubic feet per minute at 50 Pascals | |
CHP | combined heat & power | |
CO | carbon monoxide | |
CO | certificate of occupancy | |
CO2 | carbon dioxide | |
COP | coefficient of performance | |
CYA | cover your ass | |
CZ | climate zone | |
DIY | do it yourself | |
DOE | Department of Energy | |
ECM | electronically commutated motor | |
EEM | energy efficient mortgage | |
EER | energy efficiency ratio | |
EF | energy factor | |
EFL | Environments for Living | |
EIA | Energy Information Administration | |
EIM | Energy Improvement Mortgage | |
ELA | envelope/enclosure leakage area | |
ELR | Envelope/Enclosure Leakage Ratio | |
EPA | Environmental Protection Agency | |
EPS | expanded polystyrene | |
EqLA | equivalent leakage area | |
ERV | energy (or enthalpy) recovery ventilator | |
ES / ESTAR | Energy Star | |
ES V3 | Energy Star version 3 | |
FHA | U.S. Federal Housing Authority | |
FLA | four letter acronym or five letter acronym | |
FROG | finished room over garage | |
GBA | Green Building Advisor | |
GC | general contractor | |
GSHP | ground-source heat pump | |
GWP | global warming potential | |
HDD | heating degree days | |
HEPA | high efficiency particulate air | |
HERS | Home Energy Rating System | |
HOT2000 | A type of Canadian energy modeling software | |
HP | home performance | |
HPwES | Home Performance with Energy Star | |
HRV | heat recovery ventilator | |
HSPF | heating season performance factor | |
HUD | U.S. Department of Housing and Urban Development | |
HVAC | Heating, Ventilating, & Air Conditioning | |
IAQ | indoor air quality | |
ICAT | insulation contact, air tight (designation for recessed can lights) | |
ICC | International Code Council | |
ICF | insulated concrete form | |
IEA | International Energy Agency | |
IECC | International Energy Conservation Code | |
IEQ | indoor environmental quality | |
IR | infrared | |
IRC | International Residential Code | |
IREC | Interstate Renewable Energy Council | |
iwc | inches of water column (pressure unit) | |
iwg | inches of water gauge (pressure unit, same as iwc) | |
KISS | keep it simple, stupid | |
LBL | Lawrence Berkeley Laboratory (old name, still used by some) | |
LBNL | Lawrence Berkeley National Laboratory | |
LCA | life cycle analysis | |
LED | light emitting diode | |
LEED | Leadership in Energy & Environmental Design | |
LEED AP | LEED Accredited Professional | |
MEC | Model Energy Code | |
MERV | Minimum Efficiency Reporting Value | |
NAHB | National Association of Home Builders | |
NAPHN | North American Passive House Network (a.k.a. APHN) | |
NASEO | National Association of State Energy Offices | |
NATE | North American Technician Excellence | |
NCI | National Comfort Institute (not to be confused with Comfort Institute) | |
NIST | National Institute of Standards and Technology | |
NPP | neutral pressure plane | |
NPV | net present value | |
NREL | National Renewable Energy Laboratory | |
NZE | Net Zero Energy | |
OCEAN | Online Code Environment and Advocacy Network | |
OEM | original equipment manufacturer | |
ORNL | Oak Ridge National Laboratory | |
OSB | oriented strand board | |
OVE | Optimal Value Engineering (includes advanced framing) | |
PDW | pre-drywall | |
PHAUS | Passive House Alliance U.S. | |
PHIUS | Passive House Institute U.S. | |
PM | project manager | |
PPE | personal protective equipment | |
PSC | permanent split capacitor | |
PTAC | packaged terminal air conditioner | |
PTHP | packaged terminal heat pump | |
PV | photovoltaic | |
PV | present value | |
QA | quality assurance | |
QAD | Quality Assurance Designee | |
RECS | Residential Energy Consumption Survey | |
RESNET | Residential Energy Services Network | |
RH | relative humidity | |
RTFM | read the friendly manual | |
SDO | Standards Development Organization (ANSI designation) | |
SEER | seasonal energy efficiency ratio | |
SFBE | square footage of building enclosure | |
SHF or SHR | sensible heat fraction (or ratio) | |
SHGC | solar heat gain coefficient | |
SIP | structural insulated panel | |
SIPA | Structural Insulated Panel Association | |
SIR | savings investment ratio | |
SMACNA | Sheet Metal and Air Conditioning Contractors’ National Association | |
SPF | spray polyurethane foam | |
SPFA | Spray Polyurethane Foam Association | |
SWAG | scientific wild-ass guess | |
TESP | total external static pressure | |
TLA | three letter acronym | |
TXV or TEV | thermal expansion valve | |
USGBC | U.S. Green Building Council | |
VOC | volatile organic compound | |
VRF | variable refrigerant flow | |
VRV | variable refrigerant volume | |
WRB | water-resistive barrier (not weather-resistant barrier) | |
wrt | with respect to | |
WUFI | Wärme-und Feuchtetransport instationär | |
XPS | extruded polystyrene | |
ZEB | zero energy building (should be ‘net’ zero) | |
ZPD | zone pressure diagnostics | |
Sorry. No definitions for the AI above. The purpose of this list is just to help people decode the letters when they hear or read them. Some of these terms are defined in the GBA glossary.
Get the full list
If you’d like the list of what is currently 153 acronyms and initials in both pdf and MS Excel formats, go here: Get the List!.
I hope you find it useful. If you’re relatively new to the field, this list 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.
Allison Bailes of Decatur, Georgia, is a speaker, writer, energy consultant, RESNET-certified trainer, and the author of the Energy Vanguard Blog. You can follow him on Twitter at @EnergyVanguard.
Footnote
†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.
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2 Comments
double jeopardy
The amusing thing is that some mechanism of GBA tries to identify
glossary terms in posted text and insert some form of the
definition in a way that isn't clear to me, perhaps it's
supposed to be a mouse-over that expands a pop-up or the like.
Reading GBA with a text-only or bare-bones browser as I usually
do, things get confusing because that text simply shows up inline
right after the term in question without even any separation
added. It's theoretically smart enough to do that only on the
first instance per post of the term and not all of them, but
makes for amusing reading sometimes.
Now imagine what happens when I read this article!
I see similar glossary mechanisms on other forums, but the terms
are simply highlighted clickable links that readers can *optionally*
follow if they want a definition. Hopefully the coming website
revamp can also present glossary references in a slightly less
stuffed-down-your-throat fashion, which will also cause slightly
less text to be sent out per page anyway.
_H*
Response to Hobbit
Hobbit,
Thanks for letting us know about one more glitch in the design of our GBA website. I really appreciate the feedback. I have added your suggestion to a long list of hoped-for improvements to the GBA web site, and I will be sharing the list with our technical team.
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