Photo may vary slightly — verify by model number before ordering.LG KNUDB181A 18,000 BTU 4-Way Ceiling Cassette Mini Split Indoor Unit, R32 (Pairs with KUSXA181A)
In stock and ordered before 1pm ET, Mon–Fri? It ships the same day from our US warehouse.
Not sure it's the right unit? Send the model and serial — help@totalhvacparts.com or 302-219-4994.
Need more than 3? Ask about factory lead time — we'll give you a real date, not a guess.
Min. order: 1 unit · Weight: 37.0 lb · Truck Freight
Overview
LG KNUDB181A is a 18,000 BTU R32 4-Way Ceiling Cassette 2×2 ceiling cassette indoor unit that works two ways: as a single-zone system with the KUSXA181A outdoor unit (sold together as the KSUDA181A system), or as one head on an LG Multi F / Multi F MAX multi-zone outdoor unit.
Key figures from the LG submittal: net weight 30.9 lb, 459 CFM airflow on high, 3.1 pints/hour dehumidification, sound pressure as low as 36 dB(A). Refrigerant connections are ø1/4 liquid and ø1/2 vapor. Requires PT-QAGW0 grille (sold separately).
What this indoor unit needs
- Outdoor unit: LG KUSXA181A (sold separately or as the KSUDA181A system). No other LG outdoor unit is an approved single-zone match for this head.
- Multi-zone: any LG Multi F / Multi F MAX R32 outdoor unit (KUMXB / KUMXA) — capacity and head count per LG's combination data manual.
- Power: fed from the outdoor unit, 208-230/60/1; interconnect wiring is field supplied per the installation manual.
- Line set: ø1/4 × ø1/2.
- Requires PT-QAGW0 grille (sold separately).
AHRI reference 214825953 (Energy Star, Energy Star Cold Climate); installation and warranty registration by an LG-trained licensed contractor — current terms are in the LG limited warranty document under Documentation.
Compatible Units
LG approves KNUDB181A only in the combinations below (per the LG engineering manual and submittal). Mixing it with any other outdoor or indoor unit is not an AHRI-rated match. Ask the parts desk if your existing equipment isn't listed.
- KUSXA181A (outdoor unit)
- KSUDA181A (system)
- LG Multi F / Multi F MAX outdoor units (KUMXB / KUMXA)
Specifications
Values in italic are not yet confirmed from OEM documentation. Ask us to verify before ordering.
Documentation
Companion Units & System Bundle
| Model | Description | Stock | ||
|---|---|---|---|---|
 |
KUSXA181ALG · Required outdoor unit | KUSXA181A 18,000 BTU R32 outdoor unit — LG's rated match for this indoor unit | ✓ In stock | View |
 |
KSUDA181ALG · Complete system | KSUDA181A bundle: this indoor unit + KUSXA181A outdoor unit in one order | ✓ In stock | View |
 |
KUMXA181ALG · Compatible multi-zone outdoor unit | KUMXA181A 18,000 BTU Multi F LGRED° outdoor unit — see LG combination data manual for allowed IDU mixes | ✓ In stock | View |
 |
KUMXA241ALG · Compatible multi-zone outdoor unit | KUMXA241A 24,000 BTU Multi F LGRED° outdoor unit — see LG combination data manual for allowed IDU mixes | ✓ In stock | View |
 |
KUMXA301ALG · Compatible multi-zone outdoor unit | KUMXA301A 30,000 BTU Multi F LGRED° outdoor unit — see LG combination data manual for allowed IDU mixes | ✓ In stock | View |
 |
KUMXA361ALG · Compatible multi-zone outdoor unit | KUMXA361A 36,000 BTU Multi F MAX LGRED° outdoor unit — see LG combination data manual for allowed IDU mixes | ✓ In stock | View |
 |
KUMXA421ALG · Compatible multi-zone outdoor unit | KUMXA421A 42,000 BTU Multi F MAX LGRED° outdoor unit — see LG combination data manual for allowed IDU mixes | ✓ In stock | View |
 |
KUMXA481ALG · Compatible multi-zone outdoor unit | KUMXA481A 48,000 BTU Multi F MAX LGRED° outdoor unit — see LG combination data manual for allowed IDU mixes | ✓ In stock | View |
After You Order
Order number and confirmation by email the moment you check out.
Pulled from our shelf — the same live count you saw on this page. In-stock orders placed before 1pm ET, Mon–Fri, leave the same business day.
Tracking number lands in your inbox the moment it leaves the building.
Check the part number on the label against your order before installing. Wrong or damaged? Tell us — we'll sort it out.
Ask the Parts Desk
Not sure this fits? Need more than what's in stock? Send the model and serial from the unit's data plate — a real person reads it and confirms before you order.
Common Questions
What does the LG KNUDB181A pair with?
LG rates KNUDB181A only with KUSXA181A (outdoor unit) or KSUDA181A (system) or LG Multi F / Multi F MAX outdoor units (KUMXB / KUMXA). Other combinations are not AHRI-matched and are not covered by the LG warranty.
What does the KNUDB181A replace?
KNUDB181A is LG's current R32 model in this position and replaces the discontinued LCN188HV4. R32 and R-410A equipment cannot be mixed — replace the indoor and outdoor unit together.
What power does the KNUDB181A need?
208-230V, 1-phase. Minimum circuit ampacity and maximum overcurrent protection are listed in the Specifications table above and on the LG submittal under Documentation; size the breaker and wire to those values and local code.
Is the submittal sheet and installation manual available for KNUDB181A?
Yes — the LG submittal data sheet, engineering manual, installation manual and warranty document are all linked under Documentation on this page and can be downloaded without an account.
Is the stock number on this page real?
Yes — it's the live count from our own shelf, not an availability estimate. If it says 3, that's how many are physically here. When it hits zero, this page says so.
Is this a genuine LG unit, or aftermarket?
Genuine LG OEM equipment — not an aftermarket substitute.
I see this listed under a different name on other sites. Is it the same part?
Yes — manufacturers and distributors sometimes use different brand names or legacy labels for the same part number. Part number KNUDB181A is identical across all name variations.
What's the warranty on this part?
Warranty terms vary by manufacturer. Contact us with your order number for details specific to this part.
How fast does this ship?
In-stock items ship the same business day on orders placed before 1pm ET, Monday–Friday. Standard ground delivers to most of the continental US in 2–5 business days. This part ships by LTL freight, so transit runs on the freight schedule — we'll contact you to arrange delivery.
Does everything ship UPS or FedEx Ground?
This part ships by truck freight rather than parcel — still free, included in the price shown, and we'll contact you to schedule delivery before it ships.Most orders ship UPS or FedEx Ground. A small number of large or heavy parts across the catalog ship by truck freight instead — that's still free, and we reach out to arrange a delivery window before those orders leave the warehouse.
