1 Time from start of nest building to departure of young is 44 to 58 days. 2  Nest building is done by both sexes and begins around April. Both parents take turns incubating three to five eggs, which hatch after 12 to 17 days.  Brood parasitism is common among cliff swallows.
Geothermal heat pumps, which pull heat from the ground making them more reliable and efficient, usually cost somewhere between $9,000 and $23,000, including installation. The price for either style of heat pump is dependent on: The heat pump brand.
1 Complete installation of a geothermal heat pump (ground-source or water-source) can cost $10,000-$25,000 or more, depending on the length and depth of the underground pipes, soil conditions and other excavation and installation factors. In an older home, adding an electric heat pump might require hiring an electrician to upgrade the electrical panel to 200 amps, which can cost an additional $1,300 -$3,000.