What is a combination of active and passive solar heating systems?

• A. Hybrid systems
• B. Combined systems
• C. Mixed solar
• D. Dual-mode system

Answer: (A)

The main idea here is combining two ways of capturing and using solar heat into one integrated system. Passive solar uses the building’s design—like proper orientation, large south-facing windows, thermal mass (concrete, stone, or brick that stores heat), and selective shading—to collect and store heat without pumps or mechanical Devices. Active solar, on the other hand, uses equipment such as collectors, pumps, and storage tanks to actively move heat where it’s needed.

A hybrid solar heating system brings these approaches together. It leverages passive elements to capture and store heat naturally, while also using active components to boost heat collection, transfer it with a fluid, and distribute it to spaces or water needs. This synergy increases efficiency and reliability, because the system can rely on passive heat when available and supplement with active heating as needed, often controllable by sensors and a central controller.

Other terms you might see are less standard or less descriptive of what’s happening in practice, whereas “hybrid” clearly describes the blend of passive and active methods in one system.