If you’ve spent a night in your van and woken up to damp windows, sticky surfaces, or musty smells, you’ve experienced the dreaded condensation problem. It’s one of the most common and frustrating issues faced by travellers — especially in cooler or humid climates.
For anyone shopping for caravans in Heatherbrae, understanding how to manage internal moisture is essential. Condensation doesn’t just make your space uncomfortable — over time, it can lead to mould, water damage, and serious health concerns.
Here’s how to beat it before it builds up.
What Causes Condensation in a Caravan?
Condensation happens when warm, moist air hits a cold surface — usually windows, walls, or ceilings. It’s the same reason your mirror fogs up after a hot shower. In a caravan, it’s intensified by:
- Limited ventilation
- Small, enclosed space
- Daily activities like cooking, breathing, and showering
- Cold night air outside
Even two people sleeping in a van can produce over a litre of water vapour overnight.
1. Improve Ventilation — Always Let Moisture Escape
Ventilation is your first line of defence. Stale, moist air must be able to escape or it will settle inside.
Best options:
- Open a roof hatch or window at night
- Install a vented skylight
- Use a 12V roof fan to circulate air
- Crack windows while cooking or using a heater
Modern caravans often come with cross-ventilation setups — but even older vans can be retrofitted.
2. Use a Dehumidifier
Portable dehumidifiers are extremely effective in small spaces. They remove moisture from the air, keeping your van dry and comfortable.
Choose between:
- Electric dehumidifiers (for powered sites or solar setups)
- Moisture-absorbing crystals (for off-grid trips)
Place units near windows or sleeping areas where vapour tends to collect. Empty water trays regularly and monitor humidity with a gauge.
3. Insulate Windows and Walls
Condensation happens when warm air hits cold surfaces — so keep those surfaces warm. Insulating your van’s interior helps balance temperature and reduce dew point formation.
Smart insulation ideas:
- Thermal window covers
- Reflective foil behind cabinetry
- Foam-backed curtains
- Insulated blinds
Insulation also improves temperature control overall — making your van warmer in winter and cooler in summer.
4. Dry Out Bedding and Cushions
Moisture doesn’t just float — it settles into fabrics. After a cold or humid night, always pull back bedding, open storage compartments, and let everything breathe.
Tips:
- Remove cushions and place them vertically
- Air mattresses daily if possible
- Use moisture-absorbing sachets in bed storage areas
If you’re travelling full-time, this becomes part of your daily routine.
5. Avoid Indoor Drying and Boiling
One of the fastest ways to fog up your van? Boil water with the windows closed or hang wet towels inside. Every drop of moisture you release inside has to go somewhere.
Instead:
- Cook with vents or windows open
- Dry towels and clothing outside
- If you must cook inside, use a lid on boiling pots
- Use an extractor fan if fitted
6. Wipe Down Surfaces Every Morning
Even with all precautions, you’ll still get some condensation from time to time. Build the habit of wiping windows, sills, and benchtops each morning with a microfibre cloth.
It takes 2 minutes and helps prevent:
- Mould spores
- Mildew smells
- Surface water damage
- Wood swelling
7. Use Natural Moisture Absorbers
Products like DampRid, charcoal sachets, or rock salt bowls are low-cost ways to pull water out of the air. They’re especially handy if you’re off-grid and can’t run appliances.
Place them:
- Under the bed
- In kitchen drawers
- Near windows
- Inside wardrobes
Replace or recharge them every couple of weeks.
8. Upgrade Your Heating Setup
Gas heaters and unflued combustion systems release moisture as a by-product. If you’re heating your van with gas, it may be making condensation worse.
Alternatives:
- Diesel heaters (dry heat, no vapour)
- Reverse cycle air conditioners (if powered)
- Electric fan heaters
Whatever you use, combine heat with good ventilation for best results.
FAQs
What’s the Best Way to Stop Condensation Overnight?
The best way to stop condensation overnight in a caravan is by combining proper ventilation and insulation. These two factors work together to prevent moisture from settling on cold surfaces. Before bed, crack a window slightly or open a roof hatch to let moist air escape. Even a 1cm gap makes a difference. Insulated window covers help by preventing warm air from contacting cold glass — which is the main trigger for fogging. If you’re parked on a powered site, run a small electric dehumidifier overnight to draw moisture from the air. For off-grid setups, moisture-absorbing crystals or sachets are better than nothing. Avoid boiling water, cooking, or drying wet gear inside in the evening, as this adds extra humidity just before temperature drops. Park with the van’s nose into the wind to reduce chill on the windows. These small habits make a big difference and can eliminate most overnight condensation.
Is Condensation in a Caravan Dangerous?
Yes — when left unchecked, condensation can be both damaging to your caravan and harmful to your health. Constant moisture leads to the growth of mould and mildew, which thrive in dark, damp environments. Breathing in mould spores can trigger allergies, asthma, and other respiratory conditions — especially in small enclosed spaces like caravans. Structurally, condensation seeps into plywood, cabinetry, and sealants, leading to warping, rot, and delamination over time. Windowsills can swell, metal frames can rust, and electrical systems can corrode. Over months or years, you might face expensive repairs or permanent damage. Even surface-level issues — like damp bedding or musty smells — can ruin your comfort and sleep quality. That’s why it’s essential to manage condensation daily with ventilation, insulation, and drying routines. Ignoring it might seem fine short term, but over time it chips away at both your van’s value and your health.
Do Dehumidifiers Work in Caravans?
Absolutely — dehumidifiers are one of the most effective tools for tackling moisture in a caravan. A small electric dehumidifier (240V) is capable of removing litres of water from the air daily, dramatically reducing fogging and dampness. Many modern units are compact, quiet, and energy-efficient — ideal for small spaces like vans. If you’re travelling off-grid, you can use moisture-absorbing options like DampRid tubs, silica gel packs, or charcoal sachets. While these passive options aren’t as powerful, they still help — especially in wardrobes, under beds, or during storage. For best results, combine both methods: use a plug-in unit when connected to mains power and passive ones when off-grid. Also, place your dehumidifier near problem areas — like around windows, in sleeping quarters, or close to the bathroom. Just remember to empty the water tank daily. Whether you’re living full-time or just doing weekend trips, dehumidifiers help keep your van dry and healthy.
How Do I Keep My Caravan Dry During Winter?
Keeping your caravan dry during winter is all about airflow, dry heat, and daily maintenance. Winter brings colder temperatures and reduced ventilation, which is the perfect recipe for condensation. To prevent this, open a window or roof hatch briefly each day — even when it’s cold — to let moisture escape. If you’re using a heater, opt for dry heating sources like diesel or electric fan heaters. Avoid unflued gas heaters, which release water vapour. Wipe down windows and surfaces each morning to catch any overnight condensation before it soaks in. Pull out bedding, cushions, and any stored items for airing, especially if you’re staying in one spot for several days. Add moisture absorbers in drawers and under beds, and use insulated window covers to reduce cold surface contact. These small efforts create a much drier environment, helping you stay comfortable and protect your van through the dampest months of the year.
Should I Insulate My Caravan Windows?
Yes — insulating your caravan windows is one of the smartest moves you can make to combat condensation. Windows are often the coldest part of the van and the first place where moisture collects. Insulated window covers act as a barrier between the cold glass and the warm air inside, dramatically reducing the dew point and preventing water build-up. Options include thermal curtains, double-layered blinds, or DIY reflectix panels cut to fit each window. Some caravan owners even install suction-mounted insulation panels for a neater finish. These also help with temperature control — keeping your van cooler in summer and warmer in winter. Beyond condensation control, insulation improves energy efficiency and adds privacy. It’s especially valuable if you’re running heating or air con, as it reduces heat loss or gain through the glass. Whether you’re a weekend traveller or a full-timer, insulating your windows offers instant comfort and long-term protection.
Speak With the Local Experts at 7th Street Caravans
If you’re living in your van full-time or planning longer getaways, moisture management is just as important as layout, battery systems, or off-road capability. The team at 7th Street Caravans can help you choose the right gear and setup to stay comfortable — and dry — no matter where the road takes you.
Start your journey with confidence — visit 7th Street Caravans or give our team a call on 02 4012 6009 for friendly, local advice.