MRCOOL DIY 4th Gen 24,000 BTU vs MRCOOL DIY 5th Gen 24,000 BTU
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Quick take: The MRCOOL DIY 5th Gen 24,000 BTU replaced the MRCOOL DIY 4th Gen 24,000 BTU, which is discontinued; the MRCOOL DIY 5th Gen 24,000 BTU is the more efficient unit (22.7 SEER2).
| Spec | MRCOOL DIY 4th Gen 24,000 BTU | MRCOOL DIY 5th Gen 24,000 BTU |
|---|---|---|
| Price | $2,500 | $3,029 |
| Rating | 4.3★ (203) | — |
| Type | Single-Zone DIY | Single-Zone DIY |
| Capacity | 24k BTU | 24k BTU |
| Coverage | ~1,000 sq ft | ~1,000 sq ft |
| SEER2 (cooling) | 20.5 | 22.7 |
| HSPF2 (heating) | 9.2 | 9.5 |
| Low-Ambient Heating | to -13°F | to -13°F |
| Max heat at 5°F (NEEP) | 15,655 BTU | 16,100 BTU |
| Heat kept at 5°F | 63% of rated | 67% of rated |
| Refrigerant | R-410A | R-454B |
| Zones | Single zone | Single zone |
| Voltage | 230V | 230V |
| WiFi Control | Built-in | Built-in |
| Install | Precharged 25-ft quick-connect lineset like its smaller siblings, but this is a 2-ton condenser — plan on two people and a proper pad or wall bracket. Needs a dedicated 208/230V circuit (30-35A max fuse). The 41-inch air handler is large; check your wall stud layout before ordering. | Precharged 25-ft Quick Connect lineset with larger 3/8" x 5/8" lines, R-454B, no vacuum pump. The condenser weighs about 123 lb, so it's a two-person lift onto a pad or MRCOOL's MB440A wall bracket. Electrical is a dedicated 208/230V circuit with a 24A minimum ampacity and 25A maximum fuse. Like every 5th Gen indoor unit it has a refrigerant leak sensor, so seal the penetration with putty or silicone instead of foam. |
| Warranty | 7-year compressor / 5-year parts with online registration (limited lifetime compressor promo when registered) | 7-year compressor / 5-year parts with registration (MRCOOL DIY Direct also offers an optional lifetime-compressor upgrade) |
Pros & cons
MRCOOL DIY 4th Gen 24,000 BTU
- ✓One condenser covers ~1,000 sq ft — often replaces two smaller units and two circuits
- ✓20.5 SEER2 / 9.2 HSPF2 with Energy Star certification
- ✓Same no-vacuum quick-connect install as the 12k despite being 2 tons
- ✓Gold Fin corrosion-resistant condenser coating for coastal/humid climates
- ✓Typical pro-install quote for this capacity runs $5,500+ — the DIY math is compelling
- ✗Freight delivery damage is the most common complaint in Home Depot reviews — inspect before signing
- ✗20.5 SEER2 trails the 12k/18k models noticeably
- ✗Heavy condenser (130+ lb) makes solo install genuinely difficult
- ✗Reports of communication board and display errors (P-codes) after a few seasons
- ✗Single-zone only — one big head struggles to condition divided floor plans evenly
MRCOOL DIY 5th Gen 24,000 BTU
- ✓Cooling efficiency rose to 22.7 SEER2 from the 4th Gen's 20.5, the biggest SEER2 gain in the lineup
- ✓16,100 BTU at 5°F is more absolute cold-weather heat than any smaller DIY size
- ✓25A maximum fuse keeps the circuit requirement modest for a 2-ton unit
- ✓Precharged lines come in lengths up to 75 ft, so the condenser doesn't have to sit right behind the head
- ✓Gold Fin coated condenser, which matters on the coast
- ✓Hybrid ducted air handlers (DIY-24-HP-MUAH) also pair with this condenser if you change your mind about a wall head
- ✗Energy Star certified but not cold-climate Energy Star on its NEEP listing, which rules it out of programs that require the cold-climate tier
- ✗COP of 2.0 at 5°F trails the 18k's 2.44, so cold-weather running costs are higher per BTU
- ✗About $500 more than the 4th Gen 24k's typical street price
- ✗123-lb condenser and a long air handler make it a real two-person install