Comparison Of Solar Air Conditioners
Review of Absorption, PV and Hybrid Thermal Air Conditioners

Listed below are the various types of solar air conditioners currently in the market (Updated 10/2012).

Solar Powered Chillers (Commercial Only)

These chiller systems can be powered by evacuated tube solar thermal collectors or solar concentrators. They can also be powered by recovering waste heat energy from various industrial or commercial process. Basically these systems run on hot water or steam that can be produced in a number of ways including using solar energy.

1. Absorption Chiller Air Conditioners - Lithium Bromide Example: Yazaki
Can run on hot water 170-200F range, within range of evacuated tube solar.

2. Adsorption Chiller Air Conditioners - Silica - Example: Eco-Max
Can run on hot water 170-200F range, within range of evacuated tube solar.

3. Absorption Chiller Air Conditioners - Ammonia - Example: Robur (Serval)
Can run on hot water >240F range, works with a parabolic solar concentrating collector.

Our team has installed and configured several evacuated tube solar-powered Yazaki systems, we have a Yazaki certified installer on staff. All of the above systems are min. 10 tons, commercial use only.

Solar PV Powered Solar Air Conditioners (Residential & Commercial)

These air conditioners use BLDC (Brushless DC) compressors, or standard type compressors, they get some or all of their power from solar. Solar photovoltaic panels produce DC power, which in some units is used natively and in others must be inverted to AC.

1. 100% DC Solar Air Conditioners - All DC compressor, fans, and controls- Example: DC48 Telco/Solar
All DC powered system built around a pure-DC VRF compressor used in off-grid solar, mobile command posts, telecom cooling. 48VDC, no inverter used, very high efficiency.

2. Hybrid AC-DC Solar Air Conditioners - Mixed Solar AC/DC - Example: ACDC12C
Officially SEER 22, and a calculated SEER equivalent of 75 or higher with 3 solar panels, accepts DC power directly, no inverter or batteries needed, uses up to 100% solar. Requires AC power connection for low sunlight or night operation.

3. "Solar Ready" AC units - AC Power - Example: Lennox
Central AC system connects to AC power inverted from solar panels and connected to AC line current (grid). Clever marketing approach, uses inverted solar power but this is an AC powered unit.

Hybrid Thermal Solar Air Conditioners (Sedna Aire and various Chinese copycats)

The manufacturer claims to have patented technology that uses solar heat added into the normal vapor compression refrigeration cycle, with the claim of saving energy as a result. These hybrid thermal solar "absorption" air conditioners are connected to a solar thermal collector, compressor discharge gas is pumped through the solar collector to pick up additional superheat prior to condensing.

1. Solar Hybrid Thermal Absorption Air Conditioner - AC w/ Solar Thermal - Example: Ecoline(Sedna Aire)

*Note. This so-called solar air conditioner is included here based only upon claims made by the manufacturer. We cannot find any data to verify the manufacturers claims and our engineers do not recognize the Sedna Aire or similar "hybrid thermal absorption systems" as a solar air conditioner because they do not believe that solar contributes to any net energy savings in the system. We have NOT tested any of these units.

One thing we find particularly curious about these claims is the Sedna water heating option. If (and we don't agree) adding extra superheat to the system somehow makes it more efficient, then immediately taking the added superheat back out to make free hot water doesn't seem to fit the storyline. Even if the basic claims are somehow correct, we don't see how you can have it both ways.

See what the professional HVAC online community says about the Sedna Aire systems:
http://hvac-talk.com/vbb/showthread.php?933472-Sedna-solar-assisted-a-c-are-the-really-efficient

See Sedna Aire PDF that claims EnergyStar, AHRI & UL (Note* None of the three claimed certifications appear to be verifiable).

More professional HVAC feedback on the Sedna Aire solar thermal hybrid air conditioner.

http://hvac-talk.com/vbb/showthread.php?896812-Solar-Assisted-A-C