| Term | Definition / Meaning / Stand for |
| AIM |
Active Interface Module |
| AOC |
Active Optical Cable |
| ADA |
Adjustable Domestic Appliance |
| ADT |
Advanced Digital Technology (security system) |
| AD |
Advertisement |
| ACR |
Air Conditioning Repair |
| A/C Unit |
Air Conditioning Unit |
| A/C |
Air Conditioning |
| AC |
Air Conditioning |
| AF |
Air Filter |
| ALC |
Air Leak Classification |
| APF |
Air Purification Filter |
| ADT |
Alarm Detection Technology |
| A/C |
Alternating Current |
| ARC |
Alternating Current |
| AHS |
American Home Shield |
| APA |
American Planning Association |
| ABA |
Anti-Bacterial Agent |
| AB |
Anti-bacterial |
| AP |
Apartment |
| ARV |
Appraised Residential Value |
| AEC |
Architectural Engineering College |
| AIS |
Architectural Information Systems |
| ASH |
Asbestos |
| AR |
Attic Room |
| A/V Receiver |
Audio/Video Receiver |
| A/V |
Audio/Video |
| AR |
Augmented Reality |
| ADT |
Automated Door Technology |
| ASP |
Automated Smart Program |
| AEP |
Automatic Entry Point |
| AFL |
Automatic Fault Locator |
| ALD |
Automatic Lighting Design |
| APS |
Automatic Payment System |
| ASM |
Automatic Shutoff Mechanism |
| ATC |
Automatic Temperature Control |
| ATP |
Automatic Transfer Pump |
| ATU |
Automatic Transfer Unit |
| AV |
Available |
| ABV |
Above |
| AGM |
Absorbent Glass Mat (battery) |
| AUP |
Acceptable Use Policy |
| ADU |
Accessory Dwelling Unit |
| ARP |
Address Resolution Protocol (for network communication in smart home devices) |
| AES |
Advanced Encryption Standard |
| ARV |
After Repair Value |
| AHU |
Air Handling Unit |
| ALT |
Alternate |
| ANSI |
American National Standards Institute |
| ASHRAE |
American Society of Heating, Refrigerating, and Air-Conditioning Engineers |
| AWG |
American Wire Gauge |
| ADA |
Americans with Disabilities Act |
| AMP |
Ampere |
| APR |
Annual Percentage Rate |
| AOB |
Any Other Business |
| APT |
Apartment |
| ASP |
Application Service Provider |
| AFCI |
Arc Fault Circuit Interrupter |
| AMI |
Area Median Income |
| AOF |
Area of Focus |
| AI |
Artificial Intelligence |
| ASAP |
As Soon As Possible |
| AV |
Audio Visual |
| AGV |
Automated Guided Vehicle |
| AEB |
Automatic Emergency Braking |
| AVR |
Automatic Voltage Regulator |
| ADR |
Average Daily Rate |