Pros and cons of battery and water-powered backup sump pumpsKen Thayer | October 23, 2019
Any homeowner who relies on a sump pump to keep their basement dry knows that anxious feeling when the power goes out during a storm. Home sump pumps operate on 120 V and are useless without power, and flooding can occur quickly with no means to pump out the drain water. Flooding is preventable as several options are available for homeowners to keep their basements dry if they lose power or their primary sump pump fails.
Power generators can provide power to a home during power loss and keep the sump pump operational. This is a great option for areas prone to power outages. Several types of generators are available.
Gasoline-powered generators are affordable, but only run as long as the supply of gasoline is available. Natural gas generators are much more expensive but can continue operating during long power outages. Other types of generators include diesel, liquid propane and solar. Regardless of the type, a generator does not help if the sump pump fails.
Backup sump pumps are installed along with the primary pump and continue to operate in the event of power loss or when a primary pump fails. The backup pump is mounted above the float for the main sump pump and turns on when the water exceeds this height. During blackouts or if the primary pump fails, the backup sump pump turns on.
The two main types of backup sump pumps are battery-powered and water-powered pumps.
Battery backup pumps
The most popular type of backup sump pump is a battery-powered pump. They are powered by a deep cycle marine battery that maintains a charge through a trickle charger. This type of pump is frequently available in an assembly that includes the primary pump and is plumbed to the same drain line. Installation is easy and can be done by most homeowners. Battery backups can operate continuously for 4 to 5 hours or intermittently as long as a day.
Water-powered backup sump pumps are an alternative to battery-powered pumps. As opposed to 120 V or battery backup pumps, water-powered pumps do not require an external electric power source. Instead, they are powered by the municipal water supply. Since the water is constantly flowing, the pump will continue to operate even during extended power outages.
As with battery-powered backup pumps, the water-powered pump is mounted above the float for the main pump and contains its own float.
Water-powered backup pumps operate on the principle of the Venturi effect. When the float for the backup pump is activated, it opens a valve connected to the municipal water supply. The municipal water flows through a constricted area in the pump ejector that increases the water velocity and reduces the pressure. This results in a suction that draws the water from the sump through a drain line and discharges it outside the house. Two gallons of water can be pumped for every gallon of municipal water. They are more expensive and complicated to install than battery-powered pumps, but they can be worth the effort and money in areas prone to flooding or power outages.
Generators and backup pumps are both proven options to keep a basement dry and save homeowners thousands of dollars in cleanup, lost property value and home damage. Each option comes with its own pros and cons, including cost and installation complexity.
Any home that experiences frequent power outages or that is prone to flooding should have a generator, backup sump pump, or both. Generators have the additional benefit of supplying power for lighting, HVAC and home appliances, but most come at a much higher cost. Each homeowner should weigh the different options carefully to select the solution that fits best their needs.
For those on a budget, water-powered backup pumps combined with a gasoline generator are a good option for a moderate cost. The water-powered pump will offer years of maintenance-free operation and operates without electricity. The gasoline generator can provide emergency power for lighting or appliances for short-term power outages.
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