How Do Solar Air Conditioning Systems Work?

If you’re looking for a way to keep your home cool while relying more on renewable energy, a solar air-conditioning (AC) system could be a smart choice. It can help you save money, improve energy efficiency, and reduce your environmental impact.

How Do Solar AC Systems Work?

All air conditioners use a compressor inside a condenser to pressurize the refrigerant. A solar-based system uses heat from the sun to create that pressure, reducing the workload on the compressor and improving energy efficiency. In solar thermal systems, the evaporating refrigerant is pumped through coils, where it absorbs heat and moisture.

These are the main types of solar AC systems:

Types of Solar AC Systems

Photovoltaic-Based Systems

These systems collect energy from solar panels to power an air-conditioning unit or a central heating and cooling system.

Solar Thermal Systems

Solar thermal systems use the sun’s energy to cool the home through a heat pump. Unlike photovoltaic systems, they don’t generate electricity.

Passive Cooling Systems

These systems incorporate landscaping and insulation to keep a home cooler but don’t rely fully on solar energy. This article won’t focus on passive cooling.

Hybrid Solar AC Systems

Hybrid systems combine photovoltaic panels with electricity and use small amounts of non-solar energy when needed. They switch between solar power and battery power, charging the battery during sunny days and drawing electricity when sunlight is limited.

Solar-Powered Absorption Chillers

Another option is solar-powered absorption chillers, also called evaporative coolers. These systems work by using fans to blow air over water-saturated materials. The fans and motors are powered by solar energy, making them an efficient alternative to traditional cooling methods.

Room-Based vs. Whole-House Solar AC Systems

Single-Room Solar AC Systems

If you only need to cool one room, a solar-powered window unit or portable solar-powered air conditioner may be a good option. Some companies, like Coolala, have developed portable solar-powered air conditioners. The Coolala unit, launched through a Kickstarter campaign, resembles a small guitar amplifier, has wheels for easy portability, and weighs only seven pounds.

Whole-House Solar AC Systems

A centralized solar-powered AC system requires more solar panels than a single-room unit. A tiny-home owner who installed a mini-split solar AC system tested the system’s battery efficiency. After nearly three days of continuous use, the batteries remained above 50% power, confirming the system’s reliability.

Factors That Affect Solar AC Performance

Determining how many solar panels are needed depends on your intended usage and the average amount of sunlight your area receives. If you’re unsure about switching to solar AC, you may want to start with a portable or single-room unit before investing in a full-home system.

Professionals May Need Tech Training

Growth in the HVAC Industry

The heating, ventilation, and air conditioning (HVAC) industry is expanding, with a projected 14% increase in HVAC mechanics and installers from 2014 to 2024.

Why HVAC Professionals Should Learn About Solar AC

Solar air conditioning is an emerging technology that allows homeowners to cool their homes sustainably. While solar AC systems work similarly to conventional ACs, HVAC professionals can benefit from additional training in solar cooling technologies.

Case Study: Solar AC for Refrigeration

An Irish gas station retrofitted its HVAC system with a solar thermal cooling system to reduce energy use in refrigerated cases. This project resulted in 41.5% average daily energy savings compared to pre-installation energy use.

The Rise of Solar Cooling

Solar cooling is becoming more popular. In 2017, at least 1,200 solar thermal installations were used for cooling—10 times the number from 2007. As more homeowners and businesses explore solar AC, HVAC professionals must be ready to answer questions and install these systems.

Future Innovations in Solar AC

New technological advancements may further improve solar AC systems. Researchers recently developed a silica-based material made of tiny spheres that can cool down surfaces, such as solar panels, without additional energy use. This material could remove half the heat absorbed by a solar panel on a sunny day, increasing efficiency by 8%.

Options Worth Exploring

Research Before Choosing a System

Before committing to a solar AC system, research different options to determine the best fit for your home. If you’re not ready for a whole-house solution, starting with a smaller system might be a good way to test its efficiency.

Consider Passive Cooling If Needed

If an active cooling system isn’t the right choice, passive cooling strategies such as strategic landscaping and improved insulation can help reduce indoor temperatures.