Product Overview
The Lennox MWLD series offers single-zone, cold climate mini-split heat pump outdoor units designed for residential and commercial applications. These systems provide efficient cooling and heating, even in low temperatures, utilizing R-32 refrigerant.
Key Specifications:
- SEER2 up to 25.0
- HSPF2 up to 11.0
- Capacity Range: 0.75 to 2 Tons
- Cooling Capacity: 9,000 to 22,000 Btuh
- Heating Capacity: 11,000 to 20,000 Btuh
- Cold Climate Heating: Down to −22°F (−30°C)
The system includes wall-mounted indoor units (MWMDS6 series) paired with outdoor units (MWLD series). The outdoor units are available in models MWLD009S6S, MWLD012S6S, MWLD015S6S, MWLD018S6S, and MWLD024S6S.
Model Number Identification
The model number follows a specific structure:
MWLD 036-S6 S-1 P
- MWLD: Series identifier (Mini-Split Wall-Mounted, Cold Climate)
- 036: Nominal Cooling Capacity (e.g., 009 for 0.75 tons, 012 for 1 ton, 015 for 1.25 tons, 018 for 1.5 tons, 024 for 2 tons)
- S6: Refrigerant Type (6 = R-32)
- S: Refrigerant Circuits (S = Single Circuits)
- 1: Minor Design Sequence (1 = 1st Revision)
- P: Voltage (P = 208/230V-1 phase-60Hz)
Other identifiers include:
- Series Type: M = Mini-Split
- Matching Indoor Unit Type: W = Wall-Mount
- Unit Type: L = Cold Climate Heat Pump
- Major Design Sequence: D = 4th Generation
- Efficiency: S = Standard
System Components
The system comprises:
- Outdoor Units: MWLD series heat pumps.
- Indoor Units: MWMD Wall-Mounted Non-Ducted Indoor Units.
- Wireless Remote Control: Furnished with all indoor units.
- Optional Controls: Advanced Wired Control Touchscreen Controller, Thermostat Adaptor (for use with any 24V thermostat).
Each outdoor unit is designed to be matched with a single indoor unit, offering flexibility in capacity and configuration.
Key Features
Applications
- Cold climate heating capability down to −22°F (−30°C).
- Available in capacities from 0.75 through 2 tons.
- Single-phase power supply (208/230V).
- Outdoor unit powers the indoor unit.
- Low sound levels, starting at 45 dBA.
- Ductless design offers an alternative for spaces where ducted systems are impractical or cost-prohibitive.
- Units are shipped factory-assembled, internally piped, and wired for easier installation.
- Outdoor units are designed for outdoor location only.
Refrigeration System
- Refrigerant: R-32, known for its low Global Warming Potential (GWP) and Zero Ozone Depletion Potential (ODP). It is classified as low toxicity and lower flammability (A2L). The unit is factory pre-charged.
- Outdoor Coil: Features aluminum fins bonded to copper tubes for efficient heat transfer.
- Outdoor Fan: Direct drive fan designed for uniform airflow, maximizing refrigeration capacity. Includes a fan guard.
Compressor
- Variable Frequency Rotary Compressor: Offers high efficiency, balanced operation for reduced vibration and quiet performance. Utilizes powerful Neodymium magnets.
- Compressor Crankcase Heater: Prevents liquid refrigerant migration during low ambient operation.
Controls
- DC Inverter Control: Provides continuous operation and adjusts capacity based on room temperature for efficient and economical performance.
- Inverter Module Protection: Safeguards against electrical differences and indicates servicing needs via the indoor unit display.
- Outdoor Unit Microprocessor: Manages electronic expansion valve, compressor timing, temperature sensing, and controls the 4-way reversing valve. Features diagnostic LEDs.
- Electronic Expansion Valve (EEV): Standard on all models for precise refrigerant flow control.
- Compressor Protection: Includes overcurrent protection (due to high ambient temperature, locked rotor, or blocked airflow) and condenser high-temperature protection (monitored by a thermistor).
- Compressor Discharge Temperature Protection: Monitors discharge line temperature to manage compressor operation.
- Voltage Protection: Protects the unit from voltage fluctuations.
- Defrost Control: Automatically activates to remove frost from the outdoor coil, ensuring efficient heating.
- Reversing Valve: A 4-way valve enables quick switching between cooling and heating modes.
Cabinet
- Constructed of heavy gauge steel.
- Features tabs on the base for secure mounting.
- Includes condensate drain outlets on the unit base (drain connection is field-supplied).
- Optional pan heater available to prevent ice build-up in the bottom of the unit during heating operation.
- Provides access covers for power/control wiring and service valves.
- Flare connections for refrigerant lines.
Indoor Units Overview
The MWMD Wall-Mounted Indoor Units are designed for unobtrusive installation:
- Eliminate the need for ductwork, preserving space.
- Feature a compact and aesthetically pleasing design that blends into any room.
- Operate at low sound levels.
- Swing louvers adjust angles up to 90°.
- The "Calm Air Feature" uses micro-holes in the panel for a dispersed, gentle airflow when louvers are closed.
- Designed for horizontal installation on a vertical wall.
- Equipped with vacuum or washable reusable filter media.
- Include flare connections and a furnished wall plate for installation.
- A wireless remote controller is included.
Specifications
009-015 Series
| Model | MWLD009S6S | MWLD012S6S | MWLD015S6S |
|---|---|---|---|
| Tons | 0.75 | 1 | 1.25 |
| Ambient Temperature Range - °F (Cooling) | 0 to 115 | 0 to 115 | 0 to 115 |
| Ambient Temperature Range - °F (Heating) | -22 to 75 | -22 to 75 | -22 to 75 |
| Connections (Liquid/Gas - in.) | 1/4 / 3/8 | 1/4 / 3/8 | 1/4 / 1/2 |
| Maximum pipe length for all rooms - ft | 66 | 66 | 98 |
| Maximum height difference between indoor and outdoor units - ft | 49 | 49 | 66 |
| Refrigerant Charge (R-32) | 2 lbs. 2 oz. | 2 lbs. 2 oz. | 3 lbs. 2 oz. |
| Compressor Type | BLDC Rotary | BLDC Rotary | BLDC Rotary |
| Compressor Output (kW) | 4.09 | 4.09 | 4.68 |
| Refrigerant oil type | POE | POE | POE |
| Initial oil charge - oz | 11.8 | 11.8 | 15.2 |
| Outdoor Fan Number and Type | 1 Propeller | 1 Propeller | 1 Propeller |
| Outdoor Fan cfm | 1560 | 1560 | 2013 |
| Outdoor Fan Motor Type | BLDC | BLDC | BLDC |
| Outdoor Fan Motor Output (W) | 40 | 40 | 125 |
| Outdoor Coil Type | Aluminum Fin/Copper Tube | Aluminum Fin/Copper Tube | Aluminum Fin/Copper Tube |
| Sound Data (dBA) Cooling | 45 | 46 | 48 |
| Shipping Data Net | 71 | 71 | 108 |
| Shipping Gross | 77 | 77 | 116 |
| Electrical Data Line voltage (Volts-Phase-Hz) | 208/230-1-60 | 208/230-1-60 | 208/230-1-60 |
| Maximum Overcurrent Protection (MOCP) amps | 20 | 20 | 25 |
| Minimum circuit ampacity (MCA) | 12 | 12 | 12 |
018-024 Series
| Model | MWLD018S6S | MWLD024S6S |
|---|---|---|
| Tons | 1.5 | 2 |
| Ambient Temperature Range - °F (Cooling) | 0 to 115 | 0 to 115 |
| Ambient Temperature Range - °F (Heating) | -22 to 75 | -22 to 75 |
| Connections (Liquid/Gas - in.) | 1/4 / 1/2 | 1/4 / 3/8 |
| Maximum pipe length for all rooms - ft | 98 | 98 |
| Maximum height difference between indoor and outdoor units - ft | 66 | 66 |
| Refrigerant Charge (R-32) | 4 lbs. 8 oz. | 4 lbs. 8 oz. |
| Compressor Type | BLDC Rotary | BLDC Rotary |
| Compressor Output (kW) | 8.02 | 8.02 |
| Refrigerant oil type | POE | POE |
| Initial oil charge - oz | 23.7 | 23.7 |
| Outdoor Fan Number and Type | 1 Propeller | 1 Propeller |
| Outdoor Fan cfm | 2825 | 2825 |
| Outdoor Fan Motor Type | BLDC | BLDC |
| Outdoor Fan Motor Output (W) | 125 | 125 |
| Outdoor Coil Type | Aluminum Fin/Copper Tube | Aluminum Fin/Copper Tube |
| Sound Data (dBA) Cooling | 51 | 54 |
| Shipping Data Net | 150 | 150 |
| Shipping Gross | 162 | 162 |
| Electrical Data Line voltage (Volts-Phase-Hz) | 208/230-1-60 | 208/230-1-60 |
| Maximum Overcurrent Protection (MOCP) amps | 30 | 30 |
| Minimum circuit ampacity (MCA) | 20 | 20 |
AHRI System Matches
| Outdoor Unit | Indoor Unit | Cooling Capacity | SEER2 | EER2 | Heating Capacity | HSPF2 (IV) | AHRI Reference Number |
|---|---|---|---|---|---|---|---|
| MWLD009S6S-1P | MWMD009S6-1P | 9,000 | 25.0 | 16.35 | 11,000 | 10.5 | 216411305 |
| MWLD012S6S-1P | MWMD012S6-1P | 12,000 | 24.0 | 14.10 | 12,000 | 10.5 | 216411306 |
| MWLD015S6S-1P | MWMD015S6-1P | 15,000 | 23.0 | 14.55 | 15,000 | 11.0 | 216411307 |
| MWLD018S6S-1P | MWMD018S6-1P | 18,500 | 21.0 | 13.20 | 20,000 | 9.7 | 216411308 |
| MWLD024S6S-1P | MWMD024S6-1P | 22,000 | 20.0 | 12.80 | 25,000 | 9.5 | 216411309 |
Ratings are AHRI certified to AHRI Standard 210/240-2023.
- Cooling Ratings: Based on 95°F wet bulb/75°F dry bulb outdoor air temperature and 80°F dry bulb/67°F wet bulb entering indoor coil air.
- High Temperature Heating Ratings: Based on 47°F dry bulb/43°F wet bulb outdoor air temperature and 70°F dry bulb/60°F wet bulb entering indoor coil air.
- Low Temperature Heating Ratings: Based on 17°F dry bulb/15°F wet bulb outdoor air temperature and 70°F dry bulb/60°F wet bulb entering indoor coil air.
- To convert HSPF from Region IV to Region V, divide by 1.15.
Dimensions
Dimensional data is provided for different models:
MWLD009S6S | MWLD012S6S
Top View: Shows overall width (31-1/8 in. / 791 mm), depth (13-1/4 in. / 337 mm), and height (23-5/8 in. / 600 mm). Includes a 1/2 in. (13 mm) detail.
Front View: Shows height (21-5/8 in. / 549 mm) and width.
Side View: Shows width (11-1/4 in. / 285 mm) and depth.
MWLD015S6S
Top View: Shows overall width (26 in. / 660 mm), depth (14-1/8 in. / 359 mm), and height (12-1/4 in. / 311 mm). Includes a 1-inch (25 mm) detail.
Front View: Shows width (34-5/8 in. / 879 mm) and height (31-3/8 in. / 797 mm).
Bottom View: Shows width (26 in. / 660 mm) and depth (44-3/8 in. / 111 mm). Includes gas and liquid valve locations.
Side View: Shows width (13-1/4 in. / 337 mm) and height.
MWLD018S6S | MWLD024S6S
Top View: Shows overall width (37 in. / 940 mm), depth (15-1/8 in. / 384 mm), and height (24-3/8 in. / 619 mm). Includes a 6-1/8 in. (155 mm) detail and 1/2 in. (13 mm) detail.
Front View: Shows height (39-3/8 in. / 1000 mm) and width.
Bottom View: Shows width (2 in. / 51 mm) and depth.
Side View: Shows width (13 in. / 330 mm) and height. Includes liquid and gas valves (under cover) and liquid pipe inlet.
Center of Gravity
| Dimensions | 009 | 012 | 015 | 018 | 024 | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| in. | mm | in. | mm | in. | mm | in. | mm | in. | mm | |
| A | 7-1/2 | 191 | 7-1/2 | 191 | 9-7/8 | 250 | 8-1/8 | 207 | 8-1/8 | 207 |
| B | 11 | 279 | 11 | 279 | 13-3/4 | 350 | 17-1/2 | 444 | 17-1/2 | 444 |
| C | 6-1/8 | 155 | 6-1/8 | 155 | 6-3/8 | 162 | 7 | 178 | 7 | 178 |
Installation Clearances
Proper clearances are essential for optimal performance and serviceability.
Single Outdoor Unit Clearances
- Top View: Minimum 11-3/4 in. (298 mm) clearance above the unit. Minimum 6 in. (152 mm) clearance in front. Minimum 23-5/8 in. (600 mm) clearance to obstructions on sides.
- Side View: Minimum 78-3/4 in. (2000 mm) clearance for airflow on one side, with 59 in. (1499 mm) clearance to obstructions on the other side.
Multiple Outdoor Unit Clearances
When installing multiple units, specific clearances are required:
- Side View: Clearances between units vary, with minimums of 23-5/8 in. (600 mm) and 111-1/8 in. (3000 mm) for airflow, and 7-7/8 in. (200 mm) clearance to obstructions.
- Top View: Minimum 11-3/4 in. (298 mm) clearance above units, with 23-5/8 in. (600 mm) and 59 in. (1499 mm) clearances to obstructions.
- Side View (for wall-mounted): Minimum 19-5/8 in. (498 mm) clearance from the wall, with 11-3/4 in. (298 mm) clearance above and 59 in. (1499 mm) clearance to obstructions.
Sound Data
Sound pressure levels are measured in decibels (dBA) at a specified distance.
| Model | Cooling Sound Level (dBA) |
|---|---|
| MWLD009S6S-1P | 45 |
| MWLD012S6S-1P | 46 |
| MWLD015S6S-1P | 48 |
| MWLD018S6S-1P | 51 |
| MWLD024S6S-1P | 54 |
NC (Noise Criteria) curves are provided, illustrating sound pressure levels across different octave band frequencies for each model during cooling operation. These curves help assess the perceived loudness in various environments.
Note: Specifications may change. Sound pressure levels are obtained in an anechoic room and can vary based on operation conditions and acoustic environment.
Operation Range
The systems are designed for operation within specific temperature ranges:
- Cooling: Operates with indoor temperatures from 60.8°F to 89.6°F (DB) and outdoor temperatures ranging roughly from -0.4°F to 115°F (DB).
- Heating: Operates with indoor temperatures from 60.8°F to 75.2°F (DB) and outdoor temperatures ranging roughly from -22°F to 78°F (DB).
Capacity Correction
Capacity correction factors are provided to adjust performance based on pipe length and level difference between indoor and outdoor units.
9/12 KBtu/h Units
Cooling Capacity Correction
| Level Difference (ft) | Pipe Length (ft) | ||||
|---|---|---|---|---|---|
| 16 | 33 | 41 | 49 | 66 | |
| 49 | - | - | - | 0.92 | 0.90 |
| 33 | - | 0.95 | 0.94 | 0.93 | 0.91 |
| 23 | - | 0.96 | 0.95 | 0.94 | 0.92 |
| 16 | 0.99 | 0.97 | 0.96 | 0.95 | 0.93 |
| 0 | 1.00 | 0.98 | 0.97 | 0.96 | 0.94 |
| -16 | 0.99 | 0.97 | 0.96 | 0.95 | 0.93 |
| -23 | - | 0.96 | 0.95 | 0.94 | 0.92 |
| -33 | - | 0.95 | 0.94 | 0.93 | 0.91 |
| -49 | - | - | - | 0.92 | 0.90 |
Heating Capacity Correction
| Level Difference (ft) | Pipe Length (ft) | ||||
|---|---|---|---|---|---|
| 16 | 33 | 41 | 49 | 66 | |
| 49 | - | - | - | 0.92 | 0.90 |
| 33 | - | 0.95 | 0.94 | 0.93 | 0.91 |
| 26 | - | 0.96 | 0.95 | 0.94 | 0.92 |
| 16 | 0.99 | 0.97 | 0.96 | 0.95 | 0.93 |
| 0 | 1.00 | 0.98 | 0.97 | 0.96 | 0.94 |
| -16 | 0.99 | 0.97 | 0.96 | 0.95 | 0.93 |
| -26 | - | 0.96 | 0.95 | 0.94 | 0.92 |
| -33 | - | 0.95 | 0.94 | 0.93 | 0.91 |
| -49 | - | - | - | 0.92 | 0.90 |
15/18/24 KBtu/h Units
Cooling Capacity Correction
| Level Difference (ft) | Pipe Length (ft) | ||||||
|---|---|---|---|---|---|---|---|
| 16 | 33 | 41 | 49 | 66 | 82 | 98 | |
| 66 | - | - | - | - | - | 0.87 | 0.85 |
| 49 | - | - | - | 0.92 | 0.90 | 0.88 | 0.86 |
| 33 | - | 0.95 | 0.94 | 0.93 | 0.91 | 0.89 | 0.87 |
| 23 | - | 0.96 | 0.95 | 0.94 | 0.92 | 0.90 | 0.88 |
| 16 | 0.99 | 0.97 | 0.96 | 0.95 | 0.93 | 0.91 | 0.89 |
| 0 | 1.00 | 0.98 | 0.97 | 0.96 | 0.94 | 0.92 | 0.90 |
| -16 | 0.99 | 0.97 | 0.96 | 0.95 | 0.93 | 0.91 | 0.89 |
| -23 | - | 0.96 | 0.95 | 0.94 | 0.92 | 0.90 | 0.88 |
| -33 | - | 0.95 | 0.94 | 0.93 | 0.91 | 0.89 | 0.87 |
| -49 | - | - | - | 0.92 | 0.90 | 0.88 | 0.86 |
| -66 | - | - | - | - | - | 0.87 | 0.85 |
Heating Capacity Correction
| Level Difference (ft) | Pipe Length (ft) | ||||||
|---|---|---|---|---|---|---|---|
| 16 | 33 | 41 | 49 | 66 | 82 | 98 | |
| 66 | - | - | - | - | - | 0.87 | 0.85 |
| 49 | - | - | - | 0.92 | 0.90 | 0.88 | 0.86 |
| 33 | - | 0.95 | 0.94 | 0.93 | 0.91 | 0.89 | 0.87 |
| 23 | - | 0.96 | 0.95 | 0.94 | 0.92 | 0.90 | 0.88 |
| 16 | 0.99 | 0.97 | 0.96 | 0.95 | 0.93 | 0.91 | 0.89 |
| 0 | 1.00 | 0.98 | 0.97 | 0.96 | 0.94 | 0.92 | 0.90 |
| -16 | 0.99 | 0.97 | 0.96 | 0.95 | 0.93 | 0.91 | 0.89 |
| -23 | - | 0.96 | 0.95 | 0.94 | 0.92 | 0.90 | 0.88 |
| -33 | - | 0.95 | 0.94 | 0.93 | 0.91 | 0.89 | 0.87 |
| -49 | - | - | - | 0.92 | 0.90 | 0.88 | 0.86 |
| -66 | - | - | - | - | - | 0.87 | 0.85 |
Optional Accessories
Various accessories are available to complement the installation:
Outdoor Unit Accessories
- Condenser Pad: Provides a stable foundation.
- Disconnects: 30 amp fused or 60 amp non-fused options.
- Wall Brackets: Heavy-duty steel brackets for mounting outdoor units (30-inch or 36-inch).
- Whips: Heavy-duty electrical whips (10 or 8 gauge).
SpeediChannel™ System
A channel system for covering refrigerant line sets, protecting them from UV and weather. Components include starter kits, elbows, joints, and covers.
| Description | Order Number | Sizes Available (009, 012, 015, 018, 024) |
|---|---|---|
| Condenser Pad (18 x 38 x 3) | Y5014 | • • • • • |
| Disconnects (30 amp, fused, 1 ph) | 27P37 | • • • • • |
| Disconnects (60 amp, non-fused, 1 ph) | 27P39 | • • • • • |
| Wall Brackets (30 inch) | X1727 | • • N/A • • |
| Wall Brackets (36 inch) | X1728 | N/A • • • • |
| Whips (10 Gauge - 1/2 in. x 6 ft.) | 29P54 | • • • • • |
| Whips (8 Gauge - 3/4 in. x 6 ft.) | 27P44 | • • • • • |
| SpeediChannel™ Starter Kit - 4 in. | Y3387 | • • • • • |
| SpeediChannel - 4 in. x 6-1/2 ft. (qty. 6) | Y3388 | • • • • • |
| Union Coupling - 4 in. | Y3389 | • • • • • |
| 90° Flat Bend Elbow - 4 in. | Y3390 | • • • • • |
| 90° Inside Elbow - 4 in. | Y3391 | • • • • • |
| 45° Flat Bend Elbow - 4 in. | Y3392 | • • • • • |
| Flex Joint - 4 in. | Y3393 | • • • • • |
| T-Joint - 4 in. | Y3394 | • • • • • |
| Duct End - 4 in. | Y3395 | • • • • • |
| Flat Wall Escutcheon - 4 in. | Y3396 | • • • • • |
| Wall Penetration Cover - 4 in. | Y3399 | • • • • • |
| Mount Block (White) Qty, 2 - 14 in. | Y3397 | • • • • • |
| Mount Block (White) Qty, 2 - 36 in. | Y3398 | • • • • • |
Approvals and Warranty
Approvals
- AHRI Standard 210/240-2023 certified with Addenda 1 and 2.
- Rated According to U.S. Department of Energy (DOE) test procedures.
- Outdoor units and components are UL and CEC bonded for grounding to meet safety standards.
- ETL certified for the U.S. and Canada.
Warranty
- Compressor: Limited seven years.
- All other covered components: Limited five years in all applications.
- Accessories and controls: Limited one year.
Note: Refer to Lennox Basic Limited Warranty at www.Lennox.com for additional details.
