Quick Answer
Unglazed collectors can be used for heating home water, but their effectiveness and efficiency vary depending on several factors, such as climate, water volume, and desired temperature. They are often used for pool heating, but can also be applied to water heating systems.
Unglazed Collector Basics
Unglazed collectors are a type of flat plate collector that consists of a dark-colored absorber plate, insulation, and a cover. They work by transferring heat from the sun to the water flowing through the absorber plate. Unlike glazed collectors, which have a transparent cover to allow sunlight to pass, unglazed collectors rely on convection and radiation to transfer heat.
Application to Water Heating
For home water heating, unglazed collectors are often used in combination with a tank or a heat exchanger. They can be installed on flat roofs or ground-mounted, depending on the space available and local building codes. The water flow rate through the collector can range from 1 to 10 gallons per minute (GPM), depending on the system design. In areas with high solar radiation, unglazed collectors can achieve temperatures of up to 100°F (38°C) above the ambient temperature, which can be sufficient for water heating.
Comparison to Glazed Collectors
While glazed collectors are more efficient than unglazed collectors, they can be more expensive and require more maintenance. Unglazed collectors, on the other hand, are less expensive and can be more rugged, making them a good option for areas with high winds or extreme weather conditions. However, their efficiency is lower, typically ranging from 30% to 60% compared to glazed collectors, which can achieve efficiencies of 70% or higher.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.