Discussion

Does anybody know the correct procedure for sizing the boiler requirement for a swimming pool. I assumed it would be Q = m.cp.dT however even for a very small pool (80m3) the requirement I'm getting is over 400kW, which cannot be right. I was thinking about using an ASHP, which I believe to be a common way of heating a pool especially when I require a water temperature of 29oC (Think of the high CoP I should get from that!)

I have also looked through Guide G and some material by W.P Jones but cannot find anything that is of use.

Any help will very welcome.

Thanks

Andrew

A generic rule of thumb for swimming pool heat loss is 0.5C per hour. To accurately calculate the heat load you've got to consider convective, conductive and evaporative heat loss (radiant heat loss/gain wouldn't be a big issue in an internal pool).

Pool covers can significantly reduce evaporative and convective (the two biggies) heat loss. While pool tank U-values dictate the heat loss to the ground (which becomes a relatively important factor when the pool has a cover).

I believe there is a section in an ASHRAE HVAC Applications guide related to Swimming Pools (Natatoriums).

Regards, Kevin

Q [heat-up]= [Swimming pool volume X H2O Sp Heat Cap X Density]/ [recovery period in seconds i.e. 3600 fo 1hr or 1.5hrs x 3600 etc.]

Q [surface] = wind speed factor [ks] x temp diff between air to water x pool surface area

The equation does not include in-effeciencies, take heat source ineffeciencies and distribution losses [6%] into account to get the final plant size.It is worth noting that the recovery time is the pre-dominant factor in any hot water boiler plant sizing.Surface factors can be obtained from ASHRAE and CIBSE publications [Google it!].

Q [heat-up]= [Swimming pool volume X H2O Sp Heat Cap X Density x dt(pool water temp-supply water temp)]/ [recovery period in seconds]

pool temperature is generlly assumed 36-38 degC which nicely lend to have ASHP.