High-Demand Heat-Pump Water Heater
The LG Inverter Heat Pump Water Heater uses advanced inverter technology to ramp up or down in response to hot water demand, maximizing energy savings.
Heat-pump water heaters capture energy from the air and transfer it to the tank. For each kWh consumed, they can deliver three or more kWh worth of water heating. This makes them less expensive to operate than standard electric tanks and, in some areas, even cheaper than natural gas. But they can struggle to keep up with heavy hot water use, especially in cooler basements and garages. The LG Inverter Heat Pump Water Heater, introduced in 2023, seeks to address these shortcomings.
Using the same inverter technology found in variable-speed heat pumps, the LG water heater ramps compressor speeds up or down in response to hot water demand and air temperature. Like other heat-pump water heaters, the LG unit has Auto and Heat Pump–Only modes.
Auto mode, the factory setting, balances efficiency and recovery, engaging electric-resistance elements only when the heat pump can’t keep up. Heat Pump mode minimizes electric use by relying exclusively on the heat pump mechanism. LG also offers Turbo mode, which speeds up the compressor and simultaneously engages electric elements to maximize recovery rate.
LG heaters come in 58-gal. and 80-gal. sizes. The 58-gal. model has a first-hour rating of 76 gal. in Auto mode, comparable to a standard-output 50-gal. gas water heater. The 80-gal. model has a first-hour rating of 94 gal. According to LG, Turbo mode can increase recovery rate by 30%, boosting available hot water by several gallons. Unlike most tank-style heaters, the LG units have a square footprint.
Controls are on the front, with water, drain, and relief valve connections on the right side. LG offers duct adapters to allow adequate airflow for installations in small rooms. The same ThinQ app used by LG’s HVAC and consumer products can change the water heater’s operating mode, adjust the water temperature, and deliver maintenance reminders. Units can be ordered with leak-detection sensors.
An optional communication port allows users to participate in utility demand-response and time-of-use programs. LG water heaters, sold through plumbing and HVAC supply houses, have a one-year parts/10-year tank and compressor warranty. The 58-gal. unit retails for about $2000, and the 80-gal. unit for about $2900. Both qualify for federal tax credits covering 30% of the installed cost, with a maximum credit of $2000. For more information, visit lghvac.com.
— Jon Harrod; contributing editor. Photos courtesy of the manufacturer.
From Fine Homebuilding #329
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