Using a dehumidifier to remove excess moisture is a very energy-efficient way to keep your home warm. By using a dehumidifier instead of keeping your heating on, will allow you to save around £325 per year on your heating bill.
The extraction ratings you see on some manufacturers' products make false claims about the extraction rate. The rates quoted are only possible with 80% humidity and 22°C temperatures. These are like the conditions in the Amazon jungle and never experienced in the UK.