This is a 2-zone ductless mini split system for cooling and heating two separate rooms from a single outdoor condenser. It's built for homeowners who need to condition two spaces — for example a bedroom and a living area — without running ductwork, using one outdoor unit (model AMSCI4H4S42) paired with two indoor heads selected from wall-mounted or ceiling cassette styles.
The AMSCI4H4S42 outdoor condenser is part of Air-Con's Multi Split Series, rated at 42,000 BTU/h cooling capacity and 20 SEER at 208-230V, and is Energy Star qualified with AHRI certification. This 2-zone configuration pairs that outdoor unit with two indoor heads drawn from Air-Con's wall-mounted (EM) and ceiling cassette (EC) lines, per the manufacturer's published multi-split compatibility table. Note: If you would like to review the manufacturer Product Specifications, Warranty, Brochure, etc., for this system, please refer to the "Resources (System Manuals and Warranty)" Tab above on this page.
System Components
- 1x Outdoor Condenser Unit — Air-Con Multi Split Series, model AMSCI4H4S42, 42,000 BTU/h, 20 SEER, 208-230V
- 2x Indoor Heads — selectable per the Options & SKUs table below, drawn from Air-Con wall-mounted (ABXEM4H4S12, ABXEM4H4S18) and ceiling cassette (ASLEC4H4S18, ASLEK4H4S18) model families, each rated 208-230V
Installation Requirements & Accessories
- Voltage: 208-230V dedicated circuit (outdoor unit and all indoor heads)
- Line set sizing: [NEEDS VERIFICATION] — not published in source data; confirm per-zone diameters and maximum equivalent length with the installation manual
- Line Set Sold Separately — refrigerant line sets are not included with this system
- Not compatible with 115V-only circuits
- Not a confirmed match for indoor or outdoor models outside the Air-Con multi-split compatibility table published for the AMSCI4H4S42 outdoor unit
- Wall-mount bracket and cassette ceiling grille/panel inclusion is [NEEDS VERIFICATION] per indoor model selected
Pro-Installer Tip
Flare connections on 208-230V multi-zone systems are a common source of slow refrigerant leaks if the flare nut is torqued by feel instead of spec. Under-torquing leaves a joint that seeps over months, showing up later as reduced capacity or an "E1" communication fault as the system compensates; over-torquing can crack the flare face outright. Use a digital torque wrench set to the manufacturer's specified value for each line size, and pull the system down below 500 microns with a calibrated micron gauge before opening the service valves. This is not optional — EPA Section 608 requires certified technicians to verify a proper evacuation and leak-free system before charging, and doing it right the first time preserves the unit's rated 20 SEER efficiency over its service life.
Key Benefits
- Inverter-driven compressor delivers variable-speed comfort instead of blunt on/off cycling
- Single outdoor unit conditions two independent zones, each with its own indoor head and thermostat control
- Mix-and-match indoor head styles (wall mounted or ceiling cassette) let you match the room's layout
- Energy Star qualified and AHRI certified outdoor unit
- 20 SEER rating at 208-230V supports efficient part-load operation across both zones
Technical Table
| Spec | Value | Unit |
|---|---|---|
| Outdoor Unit Cooling Capacity | 42,000 | BTU/h |
| SEER | 20 | SEER |
| Voltage | 208-230 | V |
| Zone Count | 2 | zones |
| Indoor Unit Architecture | Mixed (Wall Mounted / Traditional 4-Way Ceiling Cassette) | — |
| DIY Status | No — Professional Installation Required | — |
| Energy Star Certified | Yes | — |
| AHRI Certified | Yes | — |
| Breaker Size | [NEEDS VERIFICATION] | — |
| HSPF2 | [NEEDS VERIFICATION] | — |
| Operating Temperature Range (Cooling) | [NEEDS VERIFICATION] | — |
| Operating Temperature Range (Heating) | [NEEDS VERIFICATION] | — |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Options & SKUs
| Variant (Indoor Units) | SKU | Price (USD) |
|---|---|---|
| ABXEM4H4S12 + ABXEM4H4S18 | AMSCI4H4S42-2ZONE-ABXEM4H4S12-ABXEM4H4S18 | 3667.00 |
| ABXEM4H4S12 + ASLEC4H4S18 | AMSCI4H4S42-2ZONE-ABXEM4H4S12-ASLEC4H4S18 | 3943.00 |
| ABXEM4H4S18 + ABXEM4H4S18 | AMSCI4H4S42-2ZONE-ABXEM4H4S18-ABXEM4H4S18 | 3639.00 |
| ABXEM4H4S18 + ASLEK4H4S18 | AMSCI4H4S42-2ZONE-ABXEM4H4S18-ASLEK4H4S18 | 3843.00 |
| ASLEC4H4S18 + ASLEC4H4S18 | AMSCI4H4S42-2ZONE-ASLEC4H4S18-ASLEC4H4S18 | 4191.00 |
| ASLEK4H4S18 + ABXEM4H4S18 | AMSCI4H4S42-2ZONE-ASLEK4H4S18-ABXEM4H4S18 | 3843.00 |
Compatibility & Fitment
- The AMSCI4H4S42 outdoor unit is confirmed compatible with the indoor head combinations listed in the Options & SKUs table above, per the manufacturer's multi-split compatibility table (up to 18K+18K per zone for this outdoor model).
- Indoor units ABXEM4H4S12 and ABXEM4H4S18 are wall-mounted (EM series) heads at 12,000 and 18,000 BTU respectively; ASLEC4H4S18 and ASLEK4H4S18 are ceiling cassette / concealed duct type indoor units.
- Not compatible with 115V-only circuits — this system requires a dedicated 208-230V circuit for both the outdoor unit and indoor heads.
- Not a confirmed match for outdoor units outside this listing (e.g., AMSCI4H4S18, AMSCI4H4S24, AMSCI4H4S36) or for indoor models not listed in the Air-Con multi-split compatibility table for the AMSCI4H4S42.
- Line set is not included with any variant of this system.
- Joist-bay clearance dimensions for the ceiling cassette indoor options are [NEEDS VERIFICATION].
FAQ
What breaker size do I need for this system?
Breaker size is [NEEDS VERIFICATION]. This system operates on a dedicated 208-230V circuit; consult the manufacturer's installation manual (see Resources tab) for the specific breaker and disconnect sizing for the AMSCI4H4S42 outdoor unit.
Is professional installation required to keep the warranty valid, or is this a true DIY kit?
This is a standard flare-connection multi-zone system, not a pre-charged DIY kit. Professional installation by a licensed HVAC technician is required to maintain the manufacturer warranty.
Is the line set included, and if not, what size do I need to buy?
The line set is not included. Line set sizing is [NEEDS VERIFICATION] — confirm required diameters and maximum run lengths per zone with the installation manual before ordering.
Will the ceiling cassette fit between standard 16-inch on-center joists?
If you select the ASLEC4H4S18 cassette indoor unit for a zone, joist fitment detail is [NEEDS VERIFICATION] — the source data identifies this model as a ceiling cassette (EC series) but does not publish joist-bay clearance dimensions.
Does this system work in cold climates (low-ambient heating)?
Low-ambient heating performance is [NEEDS VERIFICATION] for this configuration; the manufacturer specification data provided does not publish a heating operating temperature range for the AMSCI4H4S42.
Compliance & Warranty
This system uses standard flare-connection refrigerant lines, not a pre-charged quick-connect kit. Installation by a licensed HVAC professional is required to maintain warranty. The outdoor unit (AMSCI4H4S42) is Energy Star qualified and AHRI certified. Warranty term details beyond installation requirements are [NEEDS VERIFICATION] — refer to the "Resources (System Manuals and Warranty)" Tab above for the full manufacturer warranty document.
