Can I put a tumble dryer in a garage or an unheated room?

Moving the dryer to the garage solves several problems at once: noise, heat, humidity and floor space. It creates two others. Condensing dryers depend on a temperature difference between the drum air and the room air, and in a cold room the physics change; and an outbuilding is an electrically and environmentally different place from a kitchen, with its own requirements.

Safety

What you'll need

• The manual's stated ambient temperature range
• A properly installed fixed supply on an RCD-protected circuit
• A thermometer, to know what the space actually gets down to (optional)

Step by step

1. Find the ambient temperature range in the manual.Nearly every dryer states one. Figures around 5°C to 35°C are common, and some heat pump machines specify a higher minimum. This is the number the decision turns on, and it is model-specific.
2. Measure what the space actually gets down to.A cheap min/max thermometer left in the garage over a cold week tells you far more than an estimate. An unheated attached garage rarely freezes; a detached one regularly does.
3. Understand why heat pump machines struggle in the cold.A heat pump moves heat from the moist air to the incoming air. In a cold room the refrigerant circuit works outside its designed range, so it dries very slowly, and many machines simply refuse to start below their minimum.
4. Understand why condenser machines behave differently.A condenser dryer condenses against room air, so cold room air actually helps the condensing. What it does not help is the machine's own warm-up, and very cold ambient temperatures still fall outside the stated range.
5. Know that vented machines cope best.They simply heat incoming air and blow it out, so ambient temperature affects them least. They still need a proper vent to outside, which in a garage is usually straightforward.
6. Think about freezing.Water left in a condenser tank, in a drain hose or in the machine's sump can freeze, which can crack a container or a hose. Empty tanks after each use in winter and consider whether a plumbed drain in an unheated space will freeze.
7. Sort the electrical supply properly.A dryer is a high-current appliance and needs its own socket on a suitably protected circuit. In a garage or outbuilding that means a fixed installation by a qualified electrician, on an RCD-protected circuit. An extension lead from the house is not acceptable — it is an overheating risk and a shock risk in a damp space.
8. Deal with damp and ventilation.A condenser or heat pump machine puts heat and some humidity into the space; a garage is often damp already. Ventilation matters, and so does keeping the machine off a cold concrete floor where condensation forms under it.
9. Keep it away from stored fuel and chemicals.Petrol cans, mowers, paint, thinners and gas cylinders do not belong in the same space as an appliance that gets hot and accumulates flammable lint. Nor do items contaminated with those things belong in the drum.
10. Consider the practical route.Carrying wet washing across a cold yard in the rain to a machine that takes twice as long in winter is a real cost that does not appear in any specification.
11. Choose the type to suit the space.If the space is genuinely cold, a vented machine is the pragmatic choice despite its higher running cost, because a heat pump machine that will not start is no use at any efficiency.

Tips

• If the garage is attached and insulated, it usually stays above the minimum year round. Detached, uninsulated and single-skin is the case that causes trouble.
• A dryer standing on cold concrete will collect condensation underneath it. A sheet of ply or a moisture-resistant mat under it helps and also spreads the load.
• Bringing the machine's water tank indoors to empty and leaving it out overnight in freezing weather is a good way to crack it. Empty and refit.
• If the machine has been standing in a very cold space, letting it warm up for a few hours before running it is sensible, particularly for a heat pump machine.

Common mistakes

• Running a heat pump dryer below its minimum ambient temperature — It dries extremely slowly or refuses to start, and running a refrigerant circuit outside its design range is not good for it. The manual states the range for a reason.
• Feeding a garage dryer from an extension lead — A dryer draws a large sustained current. Extension leads overheat at the connections, and a damp outbuilding is the worst place for that. It needs a fixed, protected supply.
• Siting it next to the fuel can and the mower — Lint, heat and stored fuel or solvent is a bad combination in a space nobody is standing in while the machine runs.

If it doesn't work

Questions people ask