Solar Water Heating System for Outdoor Pools

Heating costs for outdoor pools can be more than halved with solar collectors. The private home owner has a good opportunity to eliminate all the heating costs and at the same time extend the bathing season by some weeks, during both the spring and the autumn.

A strong argument for solar heating as the heat source for slightly larger outdoor pools is that they are normally heated by an oil-fired boiler with poor summer efficiency. Here the solar collectors will efficiently replace oil-fired heating, which will otherwise cause large emissions of carbon dioxide, sulphur dioxide and nitric oxides.

For pool facilities where only the pool water is to be heated, a simple unglazed solar collector is sufficient. The chlorinated water can flow directly through the solar collectors. If domestic hot water production is also required, glazed solar collectors are used in an indirect system, in which the solar heat is transferred to heat both the chlorinated water and the domestic hot water. In indirect systems a freeze-resistant heat transfer fluid is used, which means that the solar heating system can produce heat throughout the whole year.

It is important for the customer to specify requirements regarding temperature levels, operation, guarantee and service. The normal recommended water temperature is 25 degrees Celsius. The temperature requirements together with the local conditions and the total pool area determine the size of the solar collector area. A rule of thumb for colder climates is that the solar collector area usually equals 50-100 % of the pool area. Thus an outdoor pool with an area of 500 square meters needs a solar collector area of about 250-500 square meters.

It is important to have the right basis for procurement. Always make a survey of the existing conditions. Preliminary studies or design should always be the basis of the procurement. Check whether a planning or building permit is required for this type of installation. The relevant municipal authorities, utilities and energy companies should be contacted at an early stage.

Possible damage to roof coverings, gutters, walls and pipe insulation must be noted so that new damage can be made good by the solar energy contractor under the terms of the contract. Follow the general terms for the delivery and any regulations in force in the relevant country. It is important to insure the solar heating plant/system, both during construction and after it has been put into operation.

Different tenders can easily be compared using a specification of requirements and responsibilities for installation of electricity, water, start-up, operational control, service agreement, and guarantee conditions.