Another point on tumble drying: energy efficiency ratings on vented dryers are not on the same scale as those on condenser dryers. Very few condenser dryers use less energy per cycle than a vented dryer, even though the vented dryer might be rated B or C and the condenser dryer A.
Both of which are terrible in efficiency compared to a heat pump dryer. I would recommend that anyone buying a new machine get a heat pump dryer unless you have very specific needs in terms of speed of drying or someone else is paying your electricity bill.