Ilios High Efficiency Water Heater

For locations with a gas demand of at least 4000 Therms/month, such as water parks, swimming pools, hotels, hospitals, apartment buildings & recreation centers, the Ilios High Efficiency Water Heater is a tremendous alternative to conventional systems. With a nominal heating capacity of 500,000 BTU/hour, it employs a combination of technologies designed to boost efficiency, save money, and reduce impact on the environment. This natural gas fueled water heater combines traditional boiler technology with the power of an engine driven heat pump to cut fuel consumption and carbon emissions in half. Free waste heat from the engine is captured and repurposed which adds to the unit's capacity and efficiency. The synergy of advanced heat pump and engine technology results in twice the efficiency of a gas fired boiler. The Ilios units are modular and scalable to serve larger thermal loads.

Download a copy of the Ilios High Efficiency Water Heater Data Sheet

Figure 1

How does it work?

A heat pump takes the naturally occurring energy from the environment (low temperature) and with mechanical work of a compressor, pumps this heat to higher temperature using a standard vapor compression refrigeration cycle. Heat exchangers are used to extract energy from the cold source and deliver it to the warmed media. While heat pumps can be configured many different ways, in the case of Ilios, the cold source is the outdoor environment and the warmed media is the building’s hot water. In a conventional heat pump, the compressor is driven by an electric motor. But with Ilios, a natural gas fired engine provides the shaft power. As a result, the refrigeration cycle heat is supplemented with the engine waste heat for added efficiency.

What is the performance?

A measure of efficiency is the Coefficient of Performance (COP), which is defined as the useful energy “out” (hot water), divided by the useful energy “in” (fuel). In the case of Figure 1, the COP is 550,000/292,000 = 1.9. By comparison, a typical gas fired boiler that produces 550,000 Btu/hr of hot water would consume 687,500 Btu/hr of gas (80% efficiency), or 2.3 times as much fuel as Ilios. This performance presented here is based upon favorable ambient weather conditions 80°F. For performance characterizations based upon other outdoor conditions:

Click here for graph of Heat Output vs. Outdoor Temperature

Click here for graph of COP vs. Outdoor Temperature

Ilios would like to help you determine whether this system could deliver substantial benefits to your facility, by providing a free, site-specific economic analysis .