Monitoring confirms efficiency of Passive House indoor pool

Swim­ming pools are ex­tremely en­ergy-in­tens­ive. Since many swim­ming pools in Ger­many were built in the 1970s, there is a great need for re­fur­bish­ment on a broad scale. "There is a huge po­ten­tial for sav­ings – and the data from Lün­en clearly shows that Pass­ive House is a prac­tic­able solu­tion here as well", ex­plains Søren Peper, sci­en­tif­ic ad­vi­sor at the Pass­ive House In­sti­tu­te. By build­ing to the Pass­ive House Stand­ard, hun­dreds of towns and mu­ni­cip­al­it­ies can re­duce their run­ning costs.

One of the key re­quis­ites for achiev­ing the Pass­ive House Stand­ard, also in the case of in­door swim­ming pools, is a high qual­ity build­ing en­vel­ope, in­clud­ing the glazed areas. This not only helps sig­ni­fic­antly im­prove thermal com­fort, but also al­lows for the pool to be op­er­ated at high­er levels of in­door air hu­mid­ity without caus­ing con­dens­a­tion. High­er levels of in­door air hu­mid­ity means re­duced evap­or­a­tion from the wa­ter sur­face, thus res­ult­ing in lower heat­ing re­quire­ments for the pools.

Fur­ther sav­ings can be achieved with the vent­il­a­tion sys­tem. Heat losses are re­duced by the use of high qual­ity heat ex­changers and ad­ap­ted vent­il­a­tion reg­u­la­tion. Smal­ler air quant­it­ies and the use of en­ergy-sav­ing devices provide for sig­ni­fic­antly lower con­sump­tion. Im­proved swim­ming pool tech­no­logy with en­ergy-ef­fi­cient elec­tric­al sys­tems and re­cyc­ling of fil­ter back­wash are oth­er key as­pects in this concept.

Sci­en­tif­ic mon­it­or­ing of the pro­ject in Lün­en star­ted early on in the plan­ning pro­cess. The Pass­ive House In­sti­tu­te ini­tially pre­pared a baseline study in 2009. The res­ults were dir­ec­tly in­cor­por­ated in­to the design and the most im­port­ant find­ings of this pro­cess, in­clud­ing the first en­ergy bal­ances, were pub­lished in a re­port by the in­teg­rated design team. In Septem­ber 2011, the "Lippe-Bad", a sports swim­ming fa­cil­ity with five sep­ar­ate pools, fi­nally opened its doors. The en­ergy flows in­side the build­ing were sys­tem­at­ic­ally re­cor­ded and ana­lysed for over a year up un­til March 2013.

As it is of­ten the case with com­plex new builds, the meas­ure­ment peri­od was marked by the ad­just­ments of the build­ings sys­tems. Nev­er­the­less, the val­ues for the fi­nal en­ergy con­sump­tion were still with­in the pre­dicted range, based on a pool area of 850 m², heat­ing re­quire­ment of 1189 kWh/(m² a) and elec­tri­city re­quire­ment of 718 kWh/(m² a). Al­most 12 per­cent of the elec­tri­city con­sump­tion was gen­er­ated through sol­ar en­ergy.

In the fu­ture, it will be pos­sible to re­duce the fi­nal en­ergy de­mand for the "Lippe-Bad" even fur­ther, es­pe­cially by means of the sys­tem for pro­cess­ing the fil­ter back­wash which was not in op­er­a­tion dur­ing most of the mon­it­or­ing peri­od. Fur­ther sav­ings are ex­pec­ted with ref­er­en­ce to the elec­tri­city de­mand. Like the "Bam­ba­dos" swim­ming pool in Bam­berg which was built at around the same time, this pi­lot pro­ject thus proves that even in the case of swim­ming pools the ef­fi­ciency of the Pass­ive House concept is a mod­el for the fu­ture. The com­plete mon­it­or­ing re­port and stud­ies re­lat­ing to the plan­ning are also avail­able on Pas­si­pe­dia.