Nomenclature Guide

This page is your go-to resource for understanding the model numbers and codes used in our products. Whether you’re looking to decode specifications or learn more about the industry, you’ll find everything you need to navigate our product lineup with ease.

A2L Transition Video

RR Series

NOTE:

Not all descriptors may appear for each model. See individual product specification documents for complete model number configuration options

Glossary

Section	Digit Codes	Description
Brand	F–First Co	First Co. is a leading manufacturer of multi-occupant and commercial industry HVAC products.
Cabinet Configuration	RUNV LUNV BFLX BFRX BFXX BLXX BRLX BRXX BTFX BTLX BTRX BTXX LBXX LFBX LFRX LFXX LRBX LRXX LTBX LTFX LTRX LTXX RBXX RFBX RFLX RFXX RLBX RLXX RTBX RTFX RTLX RTXX	Cabinet Configuration refers to the supply openings and riser location. The first digit is the riser’s location into the unit (R – Right, L – Left, B – Rear). The second digit is the type of first supply opening discharge (U – Universal, F – Front, L – Left, R – Right, T – Top, B – Rear). The third digit is the type of optional second supply opening discharge (F – Front, L – Left, R – Right, T – Top, B – Rear). The fourth digit is unused at this time and will remain “X”. Universal means all supply openings are knockouts.
Cabinet Height	88–88″ Standard 65–65″ 76–76″ 80–80″ XX–Special Selection	Please select the desired cabinet height. Note: adjusted heights will restrict available cabinet configurations.
Coil Configuration	30–3 Row 40–4 Row 31–3 Row/1 Row 32–3 Row/2 Row 41–4 Row/1 Row	Multiple rows of tubes increase the coil’s surface area allowing it to transfer more heat to the air passing over the coil.
Coil Connection Side	L–Left Hand R–Right Hand	The hot water supply should be connected to the bottom connection of the coil on one side. Please select which side of the unit you prefer the coil connection.
Coil Selection Options	Coil Handing–Left or Right Connection–Single Side Coil Wrapper–Galvanized Steel Fin Material-Aluminum Pressure Test–350 PSI (2.41 Mpa)	Coil handing describes at which side of the coil the header tubes are located, with airflow flowing from behind to front. A single side connection means combination coils have both headers on the same side. Galvanized steel is used to encase the coil and secure it to the unit. Fin coils are constructed of aluminum. The coils are pressure tested to 350 PSI.
Coil System	A–2-Pipe Cooling B–2-Pipe Heating C–2-Pipe Heat/Cool D–2-Pipe Heat/Cool/Aux Heat E–2-Pipe Cool/Electric Heat F–4-Pipe Heat/Cool	A 2-pipe system has one pipe for hot water supply and one for return, and can provide heating or cooling at any given time depending on the water source. A 4-pipe system has two separate pipes for hot water and two for chilled water allowing for simultaneous heating and cooling in different zones of a building.
Control Voltage	A–24V Control	Amount of voltage that operates the controls system
Heat Option	KW Heat	A higher kW in HVAC indicates more capacity for heating or cooling, but it must be matched with the specific requirements of the space and considered alongside efficiency ratings to ensure optimal performance and energy consumption.
Installation	F – Furred In E – Exposed Cabinet R – E RV Furred In	A cabinet that has been “furred in” has been built into the wall behind sheet rock. An exposed cabinet can be painted to sit directly and open in the designated space. An ERV Furred In unit has an energy recovery ventilator.
Insulation	D-Fiberglass Dual Density F–Foil Faced	Dual – Density Fiberglass is the standard insulation. The combination of a high-density skin and low-density core provides high acoustical values in the high and low frequency ranges normally encountered in HVAC equipment. Foil – Face Insulation has a reflective foil layer attached to one or both sides which reflects radiant heat, reducing heat transfer.
Insulation Thickness	2–½” Insulation 3–¾” Insulation	Please select the desired thickness of insulation.
Motor Type	E–ECM (3-SPEED)	Electronically Commutated Motors are a type of variable speed motor with built-in inverters and microprocessors that adjust speed based on demand.
Series	VCB, VFB, VSB WCB SHWC, SHWX WHDC, WHDX SVWX	Name of product family
Unit Size	CFM	An air-conditioner’s unit size or nominal capacity is the output level it can handle when functioning in either cooling or heating mode. Cubic feet per minute (CFM) measures how much airflow volume passes through a space in a minute.
Voltage	120 / 1Ph / 60Hz 208 / 1Ph / 60Hz 277 / 1Ph / 60Hz	Voltage is the electrical pressure that pushes an electric current through a circuit. Higher voltage indicates a more powerful pressure. Most HVAC systems use with 115 V (120 V) or 230V depending on size and capacity.
OPTIONS
Cabinet Options	Drain Pan Filter Frame Filter Option Option 1 Option 2	Galvanized or Stainless Steel 1” Standard Frame 1” MERV 3, 4, or 10 Standard Access or Sound Barrier None or Line of Sight Baffle
Electrical Options	Service Switch Fuses Heater Relay Thermostat Connection Float Switch	15A, 30A, 40A, 50A Toggle Switch, 60A Pull Switch None None, Electro-Mechanical None, Multi-Pin Connector, Terminal Block None, Float Switch
Controls Options	Thermostats Thermostat Location Thermostat Option	None, Fan Switch Only, Non-Prog Manual, Non-Prog Auto, Non-Progw/LCD, Programmable w/LCD, Programmable w/ Large LCD None, Unit Mount, Remote Mount, ADA Unit Mount None