The Guardian did a story with some tips for eco-friendly tumble drying. Among them….
Invest in a high-rated tumble dryer – C, B or A and make sure it has an automatic drying sensor function so it doesn’t over-dry clothes, but switches off when it senses the moisture level is low.Invest in a gas tumble dryer – they will require a registered Gas Safe installer to fit but will have a lower impact on the environment than an electric tumble dryer. Or a heat pump tumble dryer can use around 25% less energy than a standard dryer.
As much as possible, try using drying racks in sunny rooms so the tumble dryer doesn’t have to be used.
Use a high spin setting on the washing machine to get rid of as much water as possible before it comes out – the increased energy used to spin is nothing compared to the energy needed to dry clothes in a tumble dryer so there will be a benefit.