Renewable Air Conditioning

Two of the most interesting and efficient air conditioners arriving on the market this cooling season have come to us, not from the world of mainstream air conditioner manufacturers, but from renewable energy companies.

The first of them is the SplitCool DC18 solar air conditioner from Solar Panels Plus. This is a 48 volt DC air conditioning unit that employs a variable speed compressor. According to the company, their engineers started with Mitsubishi High-SEER brushless DC inverter compressor and re-engineered it in cooperation with the factory, removing the rectifier and configuring it to function on 48 volt DC power input.

There is no inverter needed or used on the inside or outside of the unit. This is important to solar energy users, because not using a AC-DC inverter avoids the power loss experienced when running a AC powered appliance on solar power. Since solar power is always native DC and 15 to 20% of the power is lost during the AC-DC conversion process, avoiding the inverter, by itself, makes this air conditioner far more efficient that a high-SEER AC unit connected to solar through an inverter.

From HotSpot Energy, another renewable energy company operating in the area of waste heat recovery, comes a new AC product called the ACWH18 Air Conditioner Water Heater. Like the solar air conditioner mentioned above, it is a 18,000 BTU ductless mini-split heat pump, but the HotSpot air conditioner-water heater runs on normal 220v AC power.

The ACWH is a SEER 18 EnergyStar certified unit that includes an integrated heat recovery circuit allowing it to make hot water as a free byproduct of running the AC.The heat recovery circuit recovers the heat that would normally be thrown away, and recycles it to make hot water at temperatures up to 140F.

The HotSpot air conditioner-water heater system installs like a normal mini-split, and then the outdoor unit is connected by insulated water lines to the customers hot water tank, using a special tank adapter. According to HotSpot engineers, it can make about 100 gallons of hot water per day, give or take, depending on its duty cycle and the entering water temperature.

The company says that a typical user with a seven month cooling season will save over $1,000 per year in combined electrical and water heating savings, compared to a customer running a SEER 13 unit and using a standard water heater, with users in southern areas like Florida able to achieve double that amount of savings. And it qualifies for a federal tax credit.

Article by Jason Burns, appearing courtesy EnergyRefuge.