7.1 Lesson 7 Introduction

Welcome to Lesson 7

Turning on the hot water tap is one of the most routine actions in your daily life, but behind that simple gesture lies a constant exchange of energy. Most homes rely on storage tank water heaters that work around the clock to keep water hot, ready for whenever you need it—even when you're asleep or away. While this convenience ensures you never have to wait for warm water, it also means your heater is constantly consuming fuel to maintain that temperature, contributing to the 12% of home energy use we discussed earlier. In this lesson we will learn about the different types of hot water heaters available on the market and compare their costs and efficiency. In this section, we'll move beyond the basic physics of heating water to understand how real-world usage, heater settings, and household habits directly impact energy consumption and cost. By connecting the formula Q = mcΔT to actual appliance operation, you'll learn how small changes in how you use hot water can lead to significant savings.

Lesson Objectives

• Identify the 6 main types of water heaters
• Calculate the energy consumption required to heat water
• Compare upfront cost vs. annual energy use of different types of hot water heaters
• Evaluate the life cycle cost of different types of hot water heaters