Frequently Asked Questions
Answers to the questions we hear most often about diesel heaters and parking air conditioners. Can't find your question? Contact us.
What size diesel heater do I need?
A 2–2.5 kW heater is enough for a car, pickup cab, small van, compact camper or boat cabin. Choose a 5 kW heater for full-size vans, RVs, truck sleeper cabs and small workshops. For garages, large tents and job sites, look at the 8 kW portable heater.
How much fuel does a diesel heater use?
A 5 kW Karlesk heater burns about 0.2 L per hour on a low setting and up to 0.45 L per hour at full power (0.05–0.12 US gallons per hour). That is a fraction of the fuel an idling engine uses.
12V or 24V — which do I need?
Match the heater or air conditioner to your vehicle's electrical system. Cars, vans, RVs and most North American trucks use 12V. Many European and Asian trucks, buses and heavy machinery use 24V.
Can a diesel heater run overnight?
Yes. Diesel air heaters are designed for long, unattended operation with the engine off. Install the heater with the exhaust and combustion air intake outside the living space and use a CO detector in any sleeping area.
Does the heater work at high altitude?
Models with high-altitude mode adjust the fuel supply for thinner air, so they keep burning cleanly in the mountains.
Can a parking air conditioner run from my battery all night?
It depends on the battery bank. A parking air conditioner draws roughly 12–55 A on 12V, depending on the model and mode. For overnight cooling we recommend a lithium house battery bank or an auxiliary power unit so the starter battery is never drained. Most Karlesk units have low-voltage protection.
What is the difference between rooftop and split air conditioners?
A rooftop unit is a single monoblock that installs in the roof hatch and ships pre-charged with refrigerant. A split system has a compact indoor unit and an outdoor condenser mounted on the back of the cab; it ships without refrigerant and must be charged by an A/C technician after installation.
Will a 220V GREE RV air conditioner work in a US RV?
No. GREE GRH-series units need 220–240 V / 50 Hz power. They are intended for European, Australian and Asian motorhomes and caravans, not for 120 V North American RV electrical systems.
Do I need professional installation?
We recommend professional installation for heaters and air conditioners. A qualified installer will route the exhaust, fuel line, wiring and refrigerant lines safely and correctly.
Where do you ship?
We ship to the United States, Canada, the European Union, the United Kingdom, Norway, Switzerland, Australia, New Zealand and a number of Asian countries. Shipping costs are calculated at checkout.