breathe in

							                    bedroom            supply air       bathroom
                                       (SUP)

                                                              Extract air
                                                              (ETA)



                    supply air                           Extract air        outdoor air
                    (SUP)                                (ETA)              (ODA)
outdoor air
               living room                toilet     kitchen
(ODA)                                                                             exhaust air
                                                                                  (EHA)



                 Extract air                        Air handling unit
                 (ETA)
               laundry room




              earth-tube - ground to earth heat exchanger




                                 EHA
                                                                ODA


                                                                                   ETA
                                                                                                                 breathe again
                                                                                                breathe in breathe out
                                                                                                  breathe deeply
                                                                                   SUP

                                    HP
                                   heat
                                  pump