heat pump or solar

May 10, 2014
I am after some advice on upgrading our heating options.

We run an above ground liner pool 6mx3mx1m at 28-31 deg C all year round. The pool is indoors and my wife uses it for animal hydrotherapy.

We are currently using an oil fired condensing boiler to heat the water.

Any views or advice on supplementing this with either solar thermal or an air source heat pump?

We are based in England in the UK so the weather can be a little poor!!

I have heard of a new style of solar using vacuum tubes around the water carrying pipes - anyone with any knowledge?




TFP Expert
LifeTime Supporter
Aug 17, 2012
Elverson Pa.
Welcome to TFP !
Just wanted to welcome you aboard.
Somebody should be along that can give better advice than me on your heating question.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Vacuum tube solar panels are designed for high delta temperatures in very cold outdoor temperatures. For normal pool heat they don't work out very well, as they are much less efficient and more expensive than conventional panels when outdoor temperatures are reasonably warm. But if you want to solar heat the pool in the winter they are about the only practical approach.

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
San Rafael, CA USA
According to Taunton, Somerset, UK monthly temperatures and looking at Solar Panel Technology Comparisons, the roughly 30ºC temperature delta between the pool water and the outside temperature at night is in the range where a glazed (glass enclosed) panel would probably be more efficient than evacuated tube panels (even adding 13% to the values in the table for the best tubes available). If you were doing domestic hot water heating which has a larger temperature difference then the evacuated tubes would be better. On cloudy days with the worst-case coldest outdoor temperatures, the evacuated tube would be a little more efficient, but during the rest of the year with warmer weather or with any sunny days the glazed panels do much better.

As for a heat pump, they don't work well with colder air temperatures. With your relatively high water temperature requirement, you'd need a special low-temperature optimized heat pump that is more expensive. Your ground may be at a warmer temperature than the air and may be a better choice as the heat source for the heat pump during the winter.

As for whether solar heating would be better than a heat pump, that is hard to say and you should cost both options and get estimates for reasonable output of each in your area.