Codes & Standards
These establish minimum acceptable safety requirements and are adopted into law by government authorities.
What are codes?
The minimum clear access opening dimensions required for an attic or crawl-space installation
What is 22 by 30 inches?
The inert gas flowed through tubing during brazing to prevent internal copper-oxide scale.
What is nitrogen (or carbon dioxide)?
The unit nameplate value used to select the proper conductor wire size.
What is the Minimum Circuit Ampacity (MCA)?
The acceptable voltage variance from the nameplate's nominal voltage before turning on the disconnect.
What is within 10%?
The organization that publishes Manual J for load calculations and Manual D for duct design
What is ACCA?
The minimum distance an outdoor unit must be raised above the ground
What is 3 inches?
The typical minimum R-value for ductwork installed in an attic.
What is R-8?
The type of overcurrent device required for compressor circuits to prevent nuisance-tripping from momentary starting current
What is a time-delay fuse (or HVACR-rated circuit breaker)?
The general warning level high-side pressure limit for an R-410A system.
What is above 450 psig?
This organization certifies matched split-system components to verify they perform as rated.
What is AHRI?
Required beneath condensing equipment in attics or closets to protect building components from water overflow.
What is an auxiliary drain pan?
The maximum safe nitrogen test pressure for systems with hermetic compressors to avoid catastrophic shell failure
What is 150 psig?
The required location for the electrical disconnect relative to the HVACR equipment.
What is within sight?
The electrical fix for a three-phase scroll compressor running with nearly equal high and low-side pressures.
What is reversing two power legs (to correct backward rotation)?
The organization responsible for developing the widely adopted National Electrical Code (NEC).
What is NFPA?
The minimum dimensions for a level service platform required at the equipment service panel in an attic.
What is 30 by 30 inches?
The physical state that zeotropic refrigerants in the 400 series must be in when leaving the cylinder.
What is a liquid?
The current rating percentage of the MCA used when sizing the equipment disconnect.
What is at least 115%?
The typical indoor design conditions used to evaluate system performance after stabilization.
What is 80F dry bulb and 67F wet bulb?
The organization that develops the International Mechanical Code and International Residential Code.
What is ICC?
The minimum height equipment must be elevated above the floor for a garage installation to avoid igniting gasoline vapors
What is 18 inches?
The typical flow temperature range for silver-alloy brazing materials on hard copper tubing
What is 1,100F to 1,400F?
The NEC section that specifically covers air-conditioning and refrigeration equipment.
What is Section 440?
The ACCA standard that dictates documentation is a core aspect of a quality installation alongside design, equipment, and distribution.
What is Standard 5 (Quality Installation Specification)?