Although it’s not a topic homeowners typically think about, water heater efficiency should get more attention — it’s the second biggest energy guzzler in most homes, writes the Environmental Protection Agency’s Dean Gamble in Builder. “Traditional gas water heaters burn gas to generate heat, sort of like a gas cooktop that heats a pot of water,” he says. “High-efficiency gas water heaters work the same way, but they squeeze as much heat as possible out of the gas before it’s exhausted out of the house. Another type of highly efficient model is now emerging. These gas condensing water heaters use a secondary heat exchanger. By extracting heat not once, but twice, the efficiency is maximized.” Gamble also notes developments in wireless connectivity and water distribution that could provide intriguing savings.