How can consumers accurately compare integrated heating and hot water systems while the only available US Government rating system called Annual Fuel Utilization Efficiency (AFUE) can underestimate actual fuel consumption by up to 47%?

The current AFUE rating system does not apply to integrated systems that also make hot water. There are no federally prescribed testing and rating standards for combined (heat and hot water) appliances. Our Government should be ashamed that because of the incomplete AFUE rating, American consumers unknowingly pay the equivalent of an extra 65 cents per gallon in fuel costs and waste over 4 billion dollars annually.

Compare two systems with the same AFUE ratings making hot water.

Cast iron boiler with indirect hot water heater 86% AFUE High mass design Standard control maintains temperature Large idle loss (not measured by AFUE), no energy recovery cycle

System 2000: 87.5% AFUE Low mass spiral design energy converter Digital control with automatic shutdown Cold start/cold finish, hybrid energy recovery

Why does the System 2000 use about half the fuel?

Source: Brookhaven National Laboratory, 2007 NYSERDA sponsored study: The performance of Integrated Hydronic Heating Systems. Both systems were tested under the same conditions making 65 gallons of hot water per day. (Average family usage)

AFUE ratings measure only burner combustion efficiency – how efficient burners are while they are running. Burner run times can be twice as long but still show the same AFUE ratings. Run times are affected by standby loss, idle loss, jacket loss, and over sizing effects, all of which are not measured by AFUE. All of these other non-measured losses simply show up in longer run times and more frequent cycles at the same AFUE.

Simply put: If a burner runs twice as long at the same AFUE, it still uses about twice the fuel! Consumers are missing important info when only comparing AFUE ratings.

These same two systems were also tested in vacation mode (family away, no hot water required at all) The conventional boiler still cycled 13 times per day as compared to the System 2000 cycling only once every other day, but when both systems ran, guess what their AFUE was while running?

The System 2000 Beats the Best!

An internationally-recognized lab confirms what we already knew: the U.S. energy (AFUE) ratings miss significant areas of energy loss. According to Brookhaven Labs tests, AFUE ratings can be off by 25% or more, an error that can under-estimate fuel consumption by up to 47%. As a result, savings with a System 2000 are much greater than comparably rated heat and hot water systems.

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