DXTH18(C,E)626A-21 – MINISPLIT HEAT PUMP SYSTEM (1.5 TON, 240V, 21 SEER2, R32)

Daizuki DXTHA-21 series single-zone ductless mini split heat pump system rated 17,500 BTU/h cooling and 18,300 BTU/h heating. The SKU is the matched pair: outdoor condenser DXTH18C626A-21 and indoor wall-mount evaporator DXTH18E626A-21, supplied with remote, interconnection cable and about 9 ft (3 m) of copper connecting pipe. 208-230V single phase, 21 SEER2 / 11.6 EER2 / 9 HSPF2, factory charged with R32.

Specifications published by the manufacturer. Source: manufacturer documentation.

Specs

• Cooling Capacity17,500 BTU/h (5,120-19,100)
• Heating Capacity18,300 BTU/h (5,120-19,100)
• Power Supply208-230V / 1Ph / 60Hz
• SEER221
• EER2 (95F)11.6
• HSPF2 (Region IV)9
• RefrigerantR32, 33.86 oz (960 g) factory charge
• Max Breaker12A
• Connecting Pipe3/8 in. gas x 1/4 in. liquid
• Max Line Length / Height Difference65 ft / 49 ft
• Outdoor Sound Level55 dB(A)
• Ships AsComplete system - condenser, evaporator, remote, cable, approx. 9 ft copper pipe

Cross-reference numbers

This part replaces the following OEM and aftermarket numbers:

• DXTH18C626A-21
• DXTH18X626A-21

Not sure if your number matches? Call (214) 340-9421 or bring the old part in — bench-testing is free.

Should I go a size up to be safe?

No - oversizing hurts worse on a minisplit than on a ducted system. An inverter has a minimum modulation floor, so a 12,000 BTU head in a 300 square foot room bottoms out, satisfies fast, and stops before it has run long enough to pull water out of the air. Dehumidification is a function of run time. Dallas dewpoints sit in the low 70s in July, so a clammy 74F room is the classic oversizing signature. Size off a room-by-room load, not a square-foot chart.

How long can the line set be, and is it precharged?

The DXTH and MKTH ship precharged for about 25 feet. Maximums land near 50 feet on smaller single-zone units and 65 on larger ones, with height limits of 33 to 49 feet. Past that you weigh in refrigerant at the per-foot rate on the data plate - read the plate, do not average what the internet says. Diameters run 1/4 inch liquid with 3/8, 1/2 or 5/8 vapor, and flare nuts get a torque wrench, not a feel.

Does it need its own circuit?

Yes, every time, sized off the MCA on the data plate. Figure 11 amps MCA on a 15 amp breaker for a 12k at 208-230V, about 13 on 20 for an 18k, 19 on 30 for a 24k. The 115V units trip people up - a 12k at 115V can pull 17 amps MCA and want a 25 amp breaker, so it does not belong on a general purpose receptacle circuit.

Can I service it with my R-410A gauges?

Not properly. These run R-32 - GWP 675, an A2L like R-454B, with no glide. Recovery machine and vacuum pump must be A2L rated with sealed spark-free electrics, the leak detector has to see A2Ls, and an R-410A manifold reads the wrong pressure-temperature curve. Recovery tank fittings are left-hand thread. Ports on the equipment are still right-hand.