Are electric water tank boosters an efficient/cost effective option?
I’ve been investigating hot water tank boosters (Rheem’s booster and the Steibel Eltron Megaboost) and found little information about their effect on DHW efficiency.
We (couple with a 5 year old) recently bought an all-electric bungalow in British Columbia with a three-bedroom basement suite. The home came with a 182L (40 imp gallon) electric resistance tank.
The tank is undersized by any listed definition. We previously rented to a couple and had no issues around hot water shortages. The home has two new model dishwashers, two laundry pairs we run on cold water only, and three bathrooms (two upstairs) with 1.5 GPM shower heads.
However we are soon renting to a party of three. A booster seems like an ideal solution to running out of hot water, given that the number of renters will likely fluctuate between 2 and 4 over the coming years. We can keep a smaller tank that seems to suit five occupants just fine but leaves room should we sometimes rent to larger groups/families. Theoretically we’d save money from reduced standby losses over the long term.
Both boosters I’ve investigated are power hogs. The Rheem model run on the same circuit and controls the hot water tank – and requires a bump to 30 amps from 20. The Megaboost IST way worse – needs a dedicated 40 amp circuit.
Would the standby savings offset the booster juice? Which setup would be the cheapest to operate?
(Before we get into heat pump water heaters – I’m hesitant because we heat the home off two single-head heat pumps and their capacity is already borderline given the home’s age and need for more air sealing (in progress.) Our utility room is also quite small in order to fit in the suite.)
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