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 Expect to pay about $2,000-$8,000 for installation of a whole-house air-source heat pump system in an average home (three-ton capacity) with existing usable ductwork. 2  The total costs can double or triple to $4,000-$24,000 or more if new ductwork must be installed or failing ductwork must be replaced.