Ok that's cool understood.
How about I flip the question..
What are the recommended options to prevent heat loss in a tub that is not filled with insulation, is outdoors, has what I consider a good cover (unlatched though).
For 6 degree warm up, from my elecric meter readings I estimate around 15kWh, which equates to about £2.20 per day, so over four summer months, that equates to around £250 heating costs alone. Which is also about £60 per month.
Would bubble wrap on the water surface provide a cheap fix?
I'm considering putting a large square garden furniture cover over the hot tub and cover but that will be £25 minimum. I'm interested in Costs vs savings.
We must all experience heat loss to a certain degree so what's the consensus?
Thanks