The Dometic Penguin II is the default rooftop air conditioner on thousands of mid-size campers and motorhomes. It comes in two cooling capacities — 13,500 BTU and 15,000 BTU. Choosing the wrong one either leaves you sweating or pays for capacity you'll never use.
The Core Difference
| Penguin II 13,500 BTU | Penguin II 15,000 BTU | |
|---|---|---|
| Power draw | ~1,500W / ~15A at 120V | ~1,700W / ~16A at 120V |
| Suggested van size | Up to ~23 ft / 180–200 sq ft | Up to ~28 ft / 220–260 sq ft |
| Weight | ~96–101 lbs (44–46 kg) | ~96–101 lbs (44–46 kg) |
| Noise | Relatively quiet for a rooftop unit | Slightly louder than the 13,500 BTU |
The footprint is identical — both fit the standard 14"×14" roof opening. A 15,000 BTU unit is a direct bolt-in replacement for a 13,500, and vice versa.
Which Capacity Do You Need?
The standard rule of thumb is 20–25 BTU per square foot in hot climates (above 90°F), or 15–20 BTU in moderate climates. For most HQ Series vans, either unit is technically adequate — the question is comfort margin.
Push toward 15,000 BTU if:
- High ambient temperature: above 105°F (40°C), the 13,500 BTU unit struggles to maintain comfortable interior temperature in a dark-roofed van
- Poor insulation: older vans or vans with large windows lose cool air faster
- You want cycling: a unit that reaches setpoint and shuts off dehumidifies better than one running flat-out continuously
Generator Use: A Key Consideration
The 15,000 BTU draws about 1.7 kW vs 1.5 kW for the 13,500 BTU. A 2,000W inverter generator (Honda EU2200i) may run the 13,500 BTU unit but can struggle with the 15,000 BTU's startup surge. If you primarily power the AC from a 2,000W generator, stick to the 13,500 BTU. A 3,000W+ generator handles either unit comfortably.
Replacement: Are They Interchangeable?
Yes. Both Penguin II models fit the 14"×14" standard roof cutout with the same electrical connections. Always use a new roof gasket when replacing a rooftop AC unit — the old gasket compresses to the shape of the previous unit and won't seal properly under a new one.
Which One to Buy
13,500 BTU: Van under 200 sq ft, moderate climates, running from a 2,000W generator, or wanting the lower price.
15,000 BTU: Camping in hot climates (Southwest US, desert summer travel), van over 200 sq ft, running from 30A shore power or 3,000W+ generator.
For Black Series HQ Series owners in warm climates, we recommend the 15,000 BTU — the extra capacity makes a noticeable difference on 38°C+ (100°F+) days.
Shop Dometic Penguin II replacement parts at RV Parts Giant.