Case Study: Taco LoadMatch® System is Efficient Choice for New Campus
With an eye to low initial installation costs, continuing energy savings and possible LEED certification, Engineering Design Services (EDS), Slatersville, R.I., chose a Taco LoadMatch® two-pipe hydronic heating and cooling system for the new $16.5 million campus complex of Meeting Street School in Providence, R.I.
LoadMatch helped constrain installation costs because the system uses fewer valves and less pipe than a conventional heating-cooling system.
It also reduced balancing, commissioning and startup labor, since LoadMatch is essentially a self-balancing system.
According to the designers of the building complex, Saccoccio and Associates, Cranston, R.I., the school's HVAC system should qualify for LEED credits in both the, "Optimize Energy Performance," and "Innovation in Design" areas of the U.S. Green Building Council rating system. Read the full case study here.
HVAC Pros Ask... Question: I need technical details on how the ZR and ZC terminals interface with the Aquastat on a boiler. I wire many boilers and all directions specify cold start or hot start, black box type instructions. I do not fully understand the inner workings, or what happens electrically with either application.
Answer: In our Control Instructions, we give two examples: a cold start boiler or a tankless coil boiler. For the cold start, the X, X goes to the TT terminals in the boiler control. For the tankless, the ZC and ZR go to the ZC, ZR terminals of the boiler. Boiler controls that don't have ZC and ZR terminals can be hooked like the cold start. These hook ups are conditional, in that you move the circulator that was originally wired to C1 and C2 over to the Taco Control.
If you plan to leave the circulator on the boiler Aquastat, and a thermostat connected to the TT terminals of the Aquastat, you will need to get into the firing circuit of the Aquastat. This would be the ZR connection. Run a wire from the ZR of the Aquastat to the ZR of the Taco control. If there is no ZR, run a black wire from the ZR of the Taco control to the B terminal of the Aquastat.
When an Aquastat has the ZC and ZR terminals, the ZC is connected to the low temperature switch of the Aquastat and to the ZC terminal of the Taco control. The ZR is connected to the ZR. These will be 120 Volt wiring. When the boiler water temp is too low, the low limit switch connected to ZC opens and drops the voltage to the ZC of the Taco board, killing all the pumps until the boiler catches up. The ZR is a 120 Volt supply to the burner circuit to fire the boiler, but this goes through the high limit switch to control the boiler water temperature.
Make TACO-HVAC.com your first stop for industry news and comprehensive product, installation and technical support from Taco.