Welcome to Lesson 10
Welcome to Lesson 10. In our last module, we explored how home heating systems and insulation work together to retain thermal energy and keep your living space comfortable during colder months. Now, we’re shifting our focus to the opposite seasonal challenge: how to effectively cool your home while managing energy use, indoor comfort, and utility costs.
As we dive into cooling strategies, we’ll also examine a critical but often overlooked factor: humidity. You’ve probably noticed that an 85°F day with high humidity feels far more oppressive than a 90°F day with dry air. This isn’t just in your head it’s thermodynamics. We’ll explore how water vapor in the air carries latent heat, interferes with your body’s natural evaporative cooling process, and forces air conditioning systems to work significantly harder to maintain comfort. Understanding this relationship will help you choose smarter cooling strategies, size equipment correctly, and avoid common energy waste.
Next, we’ll turn our attention to one of the most influential components of your building envelope: windows. While windows bring in valuable daylight and connect us to the outdoors, they can also be major pathways for unwanted summer heat gain. We’ll break down exactly how window orientation, glazing type, shading, and performance metrics like Solar Heat Gain Coefficient (SHGC) and U-factor directly impact your cooling load. You’ll learn how strategic window selection, placement, and retrofits can significantly reduce energy demand, lower your electricity bills, and improve year-round comfort.
Lesson 10 Objectives
Upon completing this lesson, you should be able to:
- Explain how natural and mechanical air-cooling systems affect building energy use
- Describe how an air conditioner works
- Describe different types of air conditioning systems
- Calculate the monetary savings when the efficiency of an air conditioner is improved
- Describe how high humidity affects both human thermoregulation and HVAC system performance
- Explain the relationship between humidity and temperature
- Identify key window performance metrics (U-factor, SHGC, VT, air leakage) and their impact on cooling demand