this process helps to concentrate the urine and increase the volume of water in the blood. Aldosterone acts via a similar method as it acts to increase the production of 3 types of channels: 1) sodium channels.
This means that a new greenhouse costing $20,000 which has a useful life of 25 years would be depreciated at a rate of 8%, twice the straight line rate, of the undepreciated value each year as compared to taking 4% of the original cost each year as the annual depreciation allowance.
According to the U.S. Department of Energy, the average lifespan of a heat pump is between 10 to 15 years. It's possible to get more life out of a unit but once you pass 15 years you are definitely on borrowed time. The good news is the new unit is almost certain to be more efficient than the one you are replacing.