ABB HygienicMaster electromagnetic meters are playing an important role in the highly instrumented residence of Amory Lovins, cofounder of Rocky Mountain Institute.
Located at an elevation of 7100 feet, the home serves to develop and demonstrate many earth-friendly architectural concepts. The latest demonstration presses into service previously unused hydronic tubing cast into the home’s concrete floor slab in 1983.
The building will now use passive and active solar heat, coupled with oversized thermal storage and backed up if necessary by renewable electricity, to add hydronic radiant floor heating to the existing solar water heating system. The building was already so efficient that it was about 99% passive-solar-heated and recently produced its 29th banana crop with no furnace; the hydronic addition seeks only to displace the last 1%, previously done with two woodstoves.
Three integrated components work together to create the building’s warmed water: a closed solar-thermal loop, a closed radiant floor loop with a single smart pump, and an open domestic hot water loop. Unusually low-friction piping design kept the pumps small in size.
Seven ABB FEH300 HygienicMaster electromagnetic flowmeters serve in these new loops. One measures flowrate of a glycol/water mixture in the solar-thermal loop that includes a 1500-gallon stratified storage tank. Four measure flow to the radiant heating floor zones. A sixth measures the return flow from the floor zones undergoing reheating in the storage tank. The final ABB magmeter measures open loop water flow to the building's domestic hot water tank. Data from these and a multitude of other sensors—some 200 data streams in all—will help researchers analyze and optimize the building's energy efficiency, and in due course to post the real-time data on the Web.
The savings generated by all the energy efficiency innovations are significant. Amory Lovins estimates the original mid-1980s savings of this superinsulated, passive-solar building at about 99 percent of normal space- and water-heating energy, 90 percent of household electricity, and 50+ percent of household water.
Work is currently ongoing to quantify and optimize further savings from the new system, which updates the technologies by 25 years to 2009 state-of-the-art. Even before the data systems are commissioned, Lovins is thrilled with the magmeters: the primary-solar-loop meter, for example, immediately revealed a failed check valve, so night thermosiphoning could be detected and corrected before it exhausted the tank’s stored heat.
Next the meters will be used to fine-tune the algorithms in a sophisticated solar-pump controller to understand the quasi-seasonal dynamics of the oversized solar storage tank. Lovins thinks his building is either the most efficient ever to be so well instrumented or the best instrumented to be so efficient. Either way, he appreciates the magmeters’ precise measurements - without consuming much of the energy they’re helping him to save.
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