The two best-selling air-cooled home standby classes in America are Generac's 22 kW Guardian and Kohler's 20 kW RESCL/RCAL line. Contractors have strong opinions; homeowners get conflicting brochures. So here's the comparison with the numbers that matter — specs taken from the current product listings, prices pulled from the live PES catalog this morning (October 19, 2026).
Spec by spec
| Generac Guardian 7043 (22 kW) | Kohler 20RCAL (20 kW) | |
|---|---|---|
| Rated output | 22.0 kW LP / 19.5 kW NG | 20 kW LP / 18 kW NG |
| Power quality | <5% THD (True Power) | <5% THD, ±1% voltage regulation |
| Enclosure | Aluminum, NEMA 3R outdoor | Aluminum, Power Armor finish, outdoor |
| Monitoring | Mobile Link Wi-Fi built in | Via RXT combined-interface board |
| Motor starting | G-Force 1000 engine | PowerBoost motor-starting |
| Noise | Check spec sheet for your install | ~66 dB(A) exercise / ~70 dB(A) running at 7 m (published) |
| Warranty | 5-year limited | 5-year / 2,000-hour limited |
Both are 120/240V single-phase, LP-or-natural-gas units in corrosion-resistant aluminum. The honest differences: Generac gives you 2 more kW and the industry's most familiar Wi-Fi monitoring; Kohler counters with published noise figures, tighter voltage regulation, and a load-shedding ATS included in the bundle price.
The price picture
- Generac Guardian 7042 — 22 kW unit only, aluminum enclosure: $6,745.90
- Generac Guardian 7043 — 22 kW + 200A service-entrance Smart Switch ATS: $8,060.18
- Kohler 20RCAL — 20 kW + RXT 200A service-entrance ATS with load management: $5,983.00
Read that again, because it's the whole story: the Kohler bundle with its transfer switch included costs $763 less than the Generac engine alone, and $2,077 less than the equivalent Generac bundle. If your load calc fits inside 18 kW on natural gas, the Kohler package is the value play by a wide margin. If you need the full 19.5 kW on NG — larger homes, multiple HVAC starts — the Generac's extra capacity is what you're paying for. Northern installs should also budget the Kohler cold-weather kit ($610.99) or Generac's equivalent either way.
Which one for which home
Pick the Generac 22 kW when the load calc demands it — big-square-footage homes running multiple compressors, or buyers who want the largest air-cooled class sold in America with the dealer network to match. Pick the Kohler 20 kW when the budget matters and 18–20 kW covers the house: you get the ATS, load shedding, and published acoustics in one line item. Both live in our 20–28 kW standby class alongside the full Generac and Kohler lines — and if your panel can't take the whole-house load, our transfer switch collection covers the partial-backup path. Want a real number for your address? Send the load list to our wholesale desk.
Frequently asked questions
Is 20 kW enough for a whole house?
For most homes under roughly 3,000 sq ft with gas heat and one central AC, yes — especially with load shedding managing the big motors. All-electric homes or dual-HVAC layouts should run a real load calc before committing; that's what pushes buyers up to 22–26 kW.
Why is the NG rating lower than the LP rating?
Natural gas carries less energy per cubic foot than propane, so the same engine produces fewer watts on NG. Compare the NG numbers if you're on utility gas: 19.5 kW (Generac) vs 18 kW (Kohler).
Do these include installation?
No — these are equipment prices. Budget separately for the pad, plumbing/gas work, electrical tie-in, and permits; your installer quotes those. We ship the equipment freight-direct with the ATS in the box where listed.
Which has better warranty support?
Both carry 5-year limited coverage (Kohler's adds a 2,000-hour cap). In practice the winner is whichever brand has the stronger service dealer near you — check before you buy, not after the first outage.
Panel, inverter, and generator drops every Tuesday — plus printable sizing charts and contractor-only deals. No spam, unsubscribe anytime.
