Never heard of ECU before? Take a look at our archived information below or feel free to read further if you really want to dive head first into ECU's use and purposes.
The ECU Waste Heat Water Heater is connected to a water heater and an air conditioner, heat pump, or refrigeration compressor. A small pump circulates cool water from the bottom of the water heater tank through the heat exchanger. Hot refrigerant gas from 
the compressor is routed through the gas side of the heat exchanger. The heated water is returned to the water tank for domestic use. The ECU heat recovery unit also reduces the compressor load, which increases compressor efficiency and extends compressor life. Reclaiming waste heat from high compressor discharge temperatures is a proven principle of energy recycling that produces abundant hot water safely and economically.
ECU Heat Recovery Units offer a limited Parts Warranty as follows:
| Model | Feature |
| HR06 | Heat pump equipped |
| HR06/V | Heat pump equipped with valves |
| HR06/V/P | Heat pump equipped with valves & PRV |
| *Add -F to any above model for freeze protection (All models suitable for use in 1.5 to 5 ton systems.) |
|
The refrigerant side of the Heat Recovery Unit Heat Exchanger is installed in the refrigerant hot gas line between the compressor and condenser; or between compressor and reversing valve, if installed on a heat Pump System. The water side of the Heat Exchanger is connected to the water heater tank to form a circulation loop. Power is drawn from the compressor contractor. Waste heat may be collected when the compressor operates, and the water circulating from the water heater tank is less than 140F. On Heat Pump Models, a minimum refrigerant temperature of 125F is also required to allow Heat Recovery operation.
CAUTION: Installations subject to freezing ambients must make provision for freeze
protection. Heat Recovery Units containing freeze stats must draw power from the line side of the compressor contractor. Drainable hand valves are suggested in addition for freeze protection.
ECU Heat Recovery Units may be mounted indoors or outdoors. They must be mounted vertically, at a height above the top of the Condenser. While normally located outdoors near the air conditioning equipment, they can be located in any convenient place, such as the garage or laundry room; but the refrigerant run should be kept to a minimum.
The Electric Company projects the utility bill savings! Florida Power says, "An average family can save up to 50% on annual water heating cost." The improved cooling performance from your air conditioner or heat pump means more savings on your utility bill. Click here to learn more...
ECU Heat Recovery Units contain a corrosion resistant double wall heat exchanger of counter flow design for high thermal efficiency. Continuously 
vented along its entire length, the ECU Heat Exchanger meets strict IAPMO safety criteria, and exceeds UL requirements.
All ECU models contain a water high limit control. It is factory set to 140 F. Heat Pump equipped models also contain a refrigerant gas low limit. It is set to 125 F. Freeze-protected models are equipped with a water low limit. It 
is factory set to 50 F, and is designed to operate when water temperatures of 40 F or less are detected, in the event of freezing ambients.
ECU Heat Recovery Units contain a low wattage direct drive single stage circulator. Standard Models use a Taco 006 series circulator. 
This pump is water lubricated, water cooled, 3250RPM, 1/40 HP, .38 amps, 230/60/1. UL listed impedance protected motor delivers flow to 12 GPM and head to 10 feet. Patented dirt barrier and replaceable cartridge.
These units will produce 5-7 gallons per hour of hot water (heated 15 F temperature rise) per ton of compressor rating, based on 250 psi minimum high side pressure using R-22, R-134A, R-500 or R-502 refrigerant.
Any air conditioner or heat pump that produces hot refrigerant at temperatures above 130° F as the gas leaves the compressor is suitable for desuperheating; that includes models that use the new R410 refrigerant. They also work with all brands, limited only by temperatures. The hotter the refrigerant gets when your air conditioner is running, the more heat you can extract and turn into hot water. The higher the energy efficiency (SEER) rating, the cooler the refrigerant temperature may be, giving the Heat Recovery Unit less to work with and slowing the production of free hot water. Some super high SEER models (18 SEER and up) don't always get hot gas temperatures above 130° F. The desuperheater doesn't operate under this condition. Ask your A/C contractor about the SEER and the operating hot gas temperature of the air conditioning system that is being presented to you, so you can make your own informed decision.