A Liquid Pool Cover (LPC) is a totally flexible automatic cover that works by forming a transparent monomolecular layer on the surface of the water whenever it is not too disturbed. This layer significantly reduces evaporation, not only saving on water heating (over 70% of loss is due to evaporation),  but far more importantly it can significantly reduce the cost of air heating and humidity control which generally represents over 75% of the total energy consumed. As with any cover, reduced evaporation means that when the pool is closed the air temperature can be set at a lower level and fresh air cut back to a minimum. Also any mechanical dehumidification will have less work to do. Contrary to a common misconception the water doesn’t have to be completely still for the LPC to work. It works to a greater or lesser degree depending on pool activity. An automatic dosing system ensures that the correct dose of Heatsavr is added at the same time each day.

24 Hour Cover

One of the real performance benefits of the LPC is its 24 hour availability, whereas for most commercial pools a conventional cover can only be used when the pool is closed which for many may be a maximum of 8 hours at night. Admittedly when the water is particularly active the effect of an LPC will be minimal. BUT the pool water doesn’t have to be completely still for Heatsavr to have some effect - it works to a greater or lesser degree dependant on pool activity, so the majority of pools will still be gaining some daytime benefit particularly during quieter periods. The effect of this during opening hours should not be underestimated.  For a typical leisure centre pool the cost of energy use relating to ventilation (fan power and heat loss) can account for over 60% of the total.

Pie Chart of Energy use

Even though air temperature reduction may not be possible during the day, any system incorporating humidity controlled variable fresh air should result in a reduction in ventilation heat loss and if also equipped with variable or two speed fans there should be additional savings in electrical consumption.



Level Deck Pools



One myth that we are keen to dispel relates to the suitability of LPC’s for deck level pools. LPC’s work perfectly well on deck level pools as testified by a year long test carried out by a local authority. The Cusum gas analysis chart below clearly shows an immediate effect at the point of introducing the LPC in Nov 2008, with a continual downward trend thereafter. Indeed 80% 0f the commercial and Local Authority pools benefitting from LPC’s are of deck level design. More information about this is available on request.




The LPC, Heatsavr, is a biodegradable liquid that is dosed into the pool at the rate of around 0.8 ml/m2/day. 90% of the liquid acts as a carrier for the active ingredient and this evaporates soon after dosing, leaving a typical concentration of around 50 parts per billion.

Heatsavr has been the subject of numerous toxicology reports, all with favourable conclusions, the most recent of which is by KIWA, a European based but internationally recognised quality authority. http://www.1kiwa.com
Safety benefits over conventional covers include manhandling issues, but probably the most significant is the avoidance of regular cleaning that is necessary with hard covers in order to prevent bacterial build which can easily occur in a rolled up cover.

Requiring only a simple programmable dosing system the set up cost for LPC’s is low and whilst there is an ongoing cost of product this can be purchased as consumed and funded by savings. A conventional cover represents a significant capital expense which has to be amortized over its life, with regular maintenance and servicing being taken into consideration. Potential savings from a LPC should be between 4 and 6 times the cost of the product. LPC’s are recommended by many Carbon Trust Consultants and are included in the list of Salix Finance approved technologies.  


Heatsaver LTD

Tel: +44(0)1737 271879

Fax: +44(0)1737 219222

email:  [email protected]

website: www.heatsaver.co.uk