Hence the relatively small projected sea level rise by the year 2100, as compared to the changes measured in tens of meters that occurred in Earth's history (see Introduction). The rise by 2100 is only a small beginning of a much larger, multi-century response of ocean and ice sheets to elevated global temperatures.
Single Speed Pool Pumps: Runs at a single speed, 3450 rpm (revolutions per minute). Imagine if your car ran at 3450 rpm - all the time, and how much gas you would use! Dual Speed Pool Pumps: Have a fourth wire coming into the pump, the low speed wire. This allows you to run the pump on low speed for 8-16 hrs per day, and high speed for 4-8 hrs. Variable Speed Pool Pumps: Operates at many speeds, programmable and self-optimizing for the highest energy efficiency and greatest energy savings.
Many residential pools in the U.S. have 1.5-horsepower or 2-horsepower pumps that draw 2,000 watts or more. If youâre not paying attention, you may be running your pool pump for 24 hours a day â even though your pool might be perfectly clean with only 6 hours of pump operation per day.f you hire a pool contractor to replace an old single-speed pump with a new variable-speed pump (which comes with a controller and programmable timer), expect to pay between $1,400 and $1,800 â significantly more than the cost to install a single-speed pump ($400 to $700) or a two-speed pump ($700 to $1,000).