Baths use a lot more water than showers, so on a simple calculation there’s more energy going down the drain each time you choose the bath over the shower.
But what happens if the water doesn’t go down the drain? It’s the equivalent of a giant radiator pumping heat into the bathroom, and eventually spreading into the rest of the house.
For showers it’s a non-starter, the average shower tray doesn’t hold much water at all, and doesn’t have a plug. But the problem with leaving the bath full of water is that it generates significant amounts of water vapour that will find it’s way to all the cold spots in your house (normally outside whatever insulation is in place) and lead to damp, mould or rot.
The solution is simply a layer of bubble wrap!
PS as expected the solution is more complicated…
- Bubble wrap gradually deflates when laid on top of water, so although the polythene continues to float, the top surface of the layer doesn’t stay dry and can cause evaporation.
- Slime: the covering being kept warm and wet starts to build up microbial slime. With a more substantial cover this can be brushed off and sterilised every now and then. But bubble wrap isn’t up to the job.
- The next attempt will probably be a tarp with elastic round the edge and a small weight in the middle to encourage condensation to run into the middle rather than the edges.