Heat decides how many months a year the van is usable, and it is one of the cheapest things in it. A diesel air heater fitted by a shop runs $2,600 to $3,900 and burns under a gallon a night. Cooling is the opposite. It costs more, weighs more, and in most of the country it loses to a fan, shade and a set of window covers.
The short answer
- A diesel air heater fitted by an American shop runs $2,600 to $3,900, the standard fit on almost every four-season build.
- Webasto publishes the Air Top 2000 STC at 3,100 to 7,000 BTU per hour, 0.03 to 0.06 gallons an hour and 1.25 to 2.45 amps.
- Across a 12 hour night that is 15 to 29 amp hours and under a gallon of fuel, which puts heat near the bottom of the running-cost list.
- A 12 volt rooftop air conditioner costs 150 to 250 amp hours a night, more than everything else in a normal van put together.
- Insulation sets the heater size. A van that holds heat runs the heater 6 hours a night; one that does not runs it 12.
- Retrofitting heat starts at $5,000 at Blue Ridge Adventure Vehicles, and Contravans fits heaters to vans other shops started.
What heating and cooling a camper van cost
A diesel air heater fitted by a professional shop runs $2,600 to $3,900 in the United States. That figure covers the unit, the fuel pickup, the exhaust routing, the ducting and the labour, and it is the entire heating system in most four-season vans. Against a $65,000 conversion it is a smaller line than the cabinetry, the fridge and the flooring around it.
Cooling is where the money moves. Heating a van means burning something, and a gallon of diesel carries more usable energy than any battery that fits under the bed. Cooling means running a compressor off that battery, which is why the appliance is the cheap half of the decision and the bank behind it is the expensive half.
| System | Fitted by a shop | What it draws | Where it earns its place |
|---|---|---|---|
| Diesel or gasoline air heater | $2,600 to $3,900 | 1.25 to 2.45 amps running | Any van used below 45 degrees, which is most of them |
| Propane furnace | $2,200 to $3,400 | Similar draw, plus a vented propane locker | Vans already carrying propane for the hob |
| Diesel hydronic system | $6,500 to $12,000 | More again, for the circulation pump | Vans that also want hot water and a warm floor |
| Powered roof fan | $600 to $1,100 | 0.1 to 2.8 amps by speed | Every van, in every climate, with no exception worth making |
| 12 volt rooftop air conditioner | $3,500 to $6,500 | 150 to 250 amp hours a night | Summer in the Southwest, on a bank built for it |
| Insulated window covers | $250 to $600 | Nothing at all | Cold nights and hot afternoons, at the best return in the van |
Two of those six rows are not optional in a van used year round. The heater and the fan go in every build we would send a buyer to. Everything else on the list is a specification argument, and the argument is settled by where the van will actually sleep rather than by what looks complete on a spec sheet.
A diesel air heater, fitted
Total$2,600 to $3,900
Ducting is the line that moves. One outlet under the bench is an afternoon. Running heat to the cab, the garage and a floor register through cabinetry that is already built is a day and a half, and it doubles that row without changing the heater at all.
The 4 ways to heat a camper van
Diesel and gasoline air heaters
The default fit, and the right answer for most vans. The unit draws fuel from the vehicle tank or a small standpipe, burns it in a chamber sealed away from the cabin, and blows the resulting heat through a duct into the living space. Nothing from the fire touches the air you breathe, and nothing from the fire puts water into the van, which is the property that matters most in a steel box you sleep in.
Webasto publishes the Air Top 2000 STC at 3,100 to 7,000 BTU per hour, or 0.9 to 2.0 kilowatts, on 0.03 to 0.06 gallons of diesel an hour and 1.25 to 2.45 amps. The unit itself weighs 5.73 pounds. Owner logs of the same heater in real use come in around 1.7 amps average, which falls inside the published band, so the manufacturer's number and the metered one agree on a component where that is rare.
Espar and Autoterm build directly comparable units and shops fit all three. The cheap all-in-one heaters sold online are usually rated at 5 kilowatts with a plastic fuel tank and a remote, and they do produce heat. What they do not come with is an exhaust route planned through your floor, a fuel line routed away from the brake lines, or anybody who signs off the work.
Propane furnaces
A propane furnace does the same job on a different fuel, and it makes sense in a van that already carries propane for the hob and the water heater. One fuel, one locker, one refill. The locker has to be sealed from the cabin and vented to the outside at the bottom, because propane is heavier than air and pools where it lands.
Catalytic and portable propane heaters are a different product and a worse one for sleeping. They are flameless and efficient, but they vent their combustion products into the room, which means water vapour into a van that is already fighting condensation. A heater that adds moisture to a cold steel box is working against the walls.
Diesel hydronic systems
A hydronic system burns diesel to heat a glycol loop, then takes heat off that loop wherever it is wanted: a fan-driven exchanger for cabin air, a heated floor, a towel rail, and domestic hot water off the same burner. It is the neat answer and the expensive one, at $6,500 to $12,000 fitted, and it is the reason it appears almost only in builds with a shower in them.
The second argument for hydronic is quieter and takes longer to notice. A glycol loop holds heat after the burner stops, so the cabin temperature moves in a gentle curve rather than a sawtooth, and there is no fan noise cycling on beside your head at 3am. Owners who have lived with both describe that as the difference, not the hot water.
Electric heat, and where it stops
Resistive electric heat is the one thing a van battery genuinely cannot do. A 1,500 watt space heater pulls 125 amps at 12 volts, which empties a 300 amp hour bank in under 2 hours and does it while an inverter throws away a slice of the energy as waste heat behind the panel. Electric heat is a shore power answer, and it is a good one on a campground pedestal in November.
Rooftop heat pumps are a real product and they do move more heat than they consume, but the ones fitted to vans are air conditioners with a reverse cycle, and their output falls away as the outside air gets colder. They earn their place in a van that already has the air conditioner and the bank, in a shoulder season. They do not replace a fuel-burning heater in a real winter.
From the desk
Almost every heater complaint we hear is an oversized heater rather than a broken one. A 5 kilowatt unit in a well-insulated 144 inch van reaches temperature in about 10 minutes, drops to its lowest burn, and then short-cycles all night, which coats the burner in soot and takes a unit that should run 8 winters down to 3. The 2 kilowatt class runs longer at a steadier output, sounds quieter because it never ramps, and is what almost every shop specifies unless the van is a 170 extended with the walls barely covered.
Sizing a camper van heater
The heater size is decided in the wall cavity, months before anybody shops for a heater. A van that holds heat asks its heater for 6 hours of running across a cold night. A van that does not asks for 12, and pays for the difference twice, once in amp hours and once in diesel, which makes the material behind the wall panels the first heating decision in the build.
With that settled, the sizing rule is short. A 2 kilowatt air heater covers an insulated 144 or 170 inch van down into genuine cold, which is why it is the class shops fit as standard. A 5 kilowatt unit is for a bigger box, a poorly covered one, or a shop that wants the van warm in 5 minutes rather than 15. Buying the bigger one for insurance is the most common sizing mistake in this category.
Altitude is the variable people meet by surprise. A combustion heater is mixing fuel with air, and thinner air changes that mixture, so a unit set at sea level runs rich at 9,000 feet and complains about it in soot and error codes. Most current units have a high-altitude mode or an automatic sensor. Ask which one you have and who sets it, because the answer is a menu option and a 20 minute job rather than a new heater.
One more input that never appears on a spec sheet: where the outlets go. Warm air rises and cold air pools at the floor, so a single outlet high on a cabinet leaves your feet cold while the thermostat above the bed reads 70 degrees. A floor-level outlet at the far end of the van from the heater does more for comfort than another kilowatt of output does.
Where the unit itself lives matters almost as much, and there are 3 usual answers: under a bench seat, under the passenger seat, or in the garage under the bed. The trade is serviceability against noise. A heater in the garage is easy to reach and audible through the bulkhead all night. One under a bench is quieter and needs the seat base out to change a glow plug. Ask which the shop uses and how long a burner service takes with the cabinetry in place.
What a camper van heater costs to run
Electrically, a diesel air heater is close to free. At 1.25 to 2.45 amps it comes to 15 to 29 amp hours across a 12 hour night, which is less than a compressor fridge uses over the same period. The startup is the only moment worth knowing about, because the glow plug pulls several times the running current for the first 2 minutes of every cycle. A heater that starts 10 times a night costs more battery than one that runs steadily, which is another argument for the smaller unit.
Fuel is the bigger line and it is still small. At the published burn, a 12 hour night is 0.36 to 0.72 gallons, so a cold month of them is 11 to 22 gallons. The EIA publishes the national on-highway diesel average weekly and had it at $5.599 a gallon on 31 August 2026, which puts a hard winter month at $60 to $121 of fuel.
Set against everything else, that is one of the smallest recurring costs in the vehicle. Fuel for the engine, insurance, campsites and connectivity all run several times it, and heat rarely changes the shape of what a van costs to run each month unless the van is parked somewhere genuinely cold for a full season.
Heating a van through a cold month
Total$68 to $141 a month
A well-insulated van never runs the heater all night. It cycles, and the top row halves, and the whole box halves with it. That is the cheapest argument anybody will make for spending money on the walls, and it only works while the walls are still open.
Carbon monoxide, and the install worth paying for
A diesel or propane air heater is safe because the fire is sealed away from the air in the van. Combustion air comes in from outside, exhaust goes out underneath, and the heat crosses into the cabin through a metal wall with nothing passing through it. That seal is the entire safety case, which means the installation is the product and the appliance is a component.
The Consumer Product Safety Commission records more than 200 accidental non-fire carbon monoxide deaths a year in the United States from consumer products, more than 100 of them from portable generators. Its guidance on alarms is written for houses and applies without amendment to a vehicle somebody sleeps in: an alarm on the level where people sleep, batteries checked, replaced on schedule.
This is the one line in a conversion where a certificate earns its keep. Only 2 of the 27 shops we compare hold RVIA certification, Storyteller Overland and DM Vans, and inspection against the industry's electrical, propane and egress standards is exactly what that certificate means. A shop without it can be just as careful; what it cannot do is prove it to you from a photograph.
Costs money to get wrong
The exhaust is the part that hurts people
A sealed heater stops being sealed in 3 ways, and none of them is visible from inside the van. An exhaust joint vibrates loose over 20,000 miles of washboard road. A tailpipe terminates under the floor pan instead of clear of the body, so exhaust washes back up through a cable grommet. Or the outlet ends within a few feet of a window that gets left open on a warm evening. Fit a carbon monoxide alarm at sleeping height rather than at the ceiling, replace it on the expiry date printed on the back, and have the exhaust inspected once a year like a tyre.
Cooling a camper van, and when the answer is no
Cooling is a shorter subject than heating, and the honest list of what works inside a van is short. There are 4 things that lower the temperature inside a van, and they go in this order: shade, glass, airflow, then a compressor. The first 3 cost a few hundred dollars between them and do most of the work. The fourth costs several thousand and forces a decision about the whole electrical system.
The roof fan does most of the work
A powered roof fan is the highest-return component in a camper van at any price. It pulls 0.1 to 2.8 amps depending on speed, it runs all night on a rounding error of battery, and it moves the hot air that collects at the ceiling out of the vehicle. What it needs to work is a second opening, because air will not leave a sealed box. A cracked window on the shaded side turns a fan from a noise into a system.
Glass is next and it is where most vans lose. Insulated reflective covers cut the sun that comes through the windows and the windscreen, at $250 to $600 for a set, and they work in both directions: the same covers hold heat in at night in February. Parking matters as much as any of it. A van in the shade at 95 degrees and a van in full sun at 95 degrees are 20 degrees apart inside, and the shade is free.
The honest limit on all of this is that airflow cannot get you below the outside temperature. A fan, covers and shade bring the interior close to ambient, which is comfortable at 85 degrees and miserable at 105. If the van's job is a national forest at 7,000 feet in July, that is the whole answer. If the job is Phoenix in August or a parking lot in Texas, nothing except a compressor works.
When a 12 volt air conditioner is worth it
Running a 12 volt rooftop unit through a warm night costs 150 to 250 amp hours, which is more than everything else in a normal van put together. A 200 amp hour battery holds about 160 usable, so one night of air conditioning empties it before dawn. Doing it properly means a bank of 600 amp hours or more, and that bank is the real price of the appliance.
Weight is the part nobody quotes. That much lithium runs 150 to 190 pounds, the rooftop unit adds 60 to 80 more, and it all comes out of a payload that is already spoken for. Mercedes publishes the payload on that chassis at 3,450 to 3,814 pounds for the 170 inch high roof 2500, and a four-season conversion with water, batteries and two adults aboard is well into it before the air conditioner arrives.
So the answer for most buyers is no, and the cases where it is yes are specific ones. Air conditioning earns its place when the van lives in the Southwest through summer, when the owner works from it in daylight, or when a dog is left in it alone. Outside those cases the same money spent on insulation, covers and a second fan buys more comfort across more nights of the year.
12 volt air conditioning, all in
Total$6,500 to $12,000, plus the payload
The unit is the cheap half. Nobody quotes the battery the unit forces you to buy, and that third row is what decides whether air conditioning is in the build or out of it. Ask for the price with and without, on the same drawing.
Four-season builds, and the shops that specify for winter
Four-season is a phrase with no definition behind it, so it is worth making it mean something before a deposit. The way to do that is to ask a temperature. A shop with a real answer will name one, say what it assumes about the walls and the windows, and tell you which parts of the van it does not warm.
Vanna Adventure Vans builds four-season rigs with high-capacity power systems in West Fargo, North Dakota, at $120,000 to $240,000, and a shop that lives through those winters specifies heat differently from one that reads about them. Rossmönster runs $130,000 to $250,000 out of Longmont, Colorado and builds for winter capability rather than a lifestyle photograph. Among the shops ranked at the top of the market, those two are the clearest cold-climate specialists, and the comparison worth making is against Papago Vans in Phoenix at $85,000 to $140,000, where the brief starts at 110 degrees and the cooling load, the insulation and the battery all move with it.
The other name worth knowing here is Off Highway Van in Salt Lake City, at $165,000 to $245,000, which builds in aerospace aluminium rather than timber. That takes several hundred pounds out of the conversion, and in a genuinely cold van those pounds go straight back into the things winter demands: more insulation, a bigger bank and the water capacity to sit still for a week.
The first thing to freeze in a cold van is never the heater. It is the water. A chassis-mounted grey tank hanging in the airstream is at outside temperature while the cabin reads 68 degrees, and a pump line run through an uninsulated void splits the first night it drops to 20. Which is why where the tanks and pump lines live is a heating decision before it is a plumbing one, and why a heat outlet into the garage is not a luxury in a winter van.
Battery temperature is the other cold-weather trap. Lithium iron phosphate cells take permanent damage if they are charged below 32 degrees, so a bank in an unheated garage under the bed is a $3,000 component sitting outside the envelope the heater is warming. A shop building for winter puts the batteries inside that envelope or fits cells with internal heating, and will say which without being pushed.
Retrofitting heat to a van you already own
A large share of the people searching for this are not buying a conversion. They already have a van, they got through one shoulder season in it, and they want heat before the next winter. That job has a price and almost nobody publishes it.
Blue Ridge Adventure Vehicles in Fairview, North Carolina takes work from $5,000, which at that end means systems rather than a whole van: electrical, insulation, a bed platform, a heater fitted properly. Contravans in Arvada, Colorado adds electrical, storage or a heater to a van somebody else already started, turns modular work around in 4 to 6 days, and runs $45,000 to $130,000 on its own full builds. Both routes exist specifically because a van does not have to be finished in one pass.
The work itself is smaller than it sounds and more invasive than it looks. A hole through the floor for the exhaust and combustion air, a tap into the fuel tank or a standpipe through the filler, a mount that carries the unit somewhere serviceable, ducting run behind cabinetry that is already built, and a thermostat somewhere that reads the room instead of the duct. Most of the labour is in the last two.
Doing it yourself puts the parts near $1,200 to $1,750 for a good unit and turns a weekend into the whole job. It is a legitimate route for somebody who has cut into a vehicle before. It is a poor first project, because the two hardest parts are the fuel tap and the exhaust, and those are the two parts that punish a mistake.
7 lines to send a shop before you pay for heat
- The make, model and rated output of the unit, in kilowatts or BTU per hour
- Where the exhaust terminates, and how far that is from every opening window and vent
- Whether fuel comes off the vehicle tank or a separate standpipe, and who plumbs it
- How many outlets, and whether one of them reaches the garage or the cab
- What altitude the unit is configured for, and who resets it when I move
- Which carbon monoxide alarm is fitted, and at what height above the mattress
- The finished weight the heater, ducting, fuel line and exhaust add, in pounds
A shop that answers all 7 in writing has fitted heaters before and has a process behind the answers. A shop that treats the list as an insult has told you what the install is going to be like, and that is useful information for the price of one email.
