Entry # 45
White's Plumbing and Heating
Brief overview of the project
This 7900 sq.ft. 14-zone radiant home in Homer, Alaska was recently converted from fuel oil to natural gas. New Rehau balancing manifolds were installed in the homes existing radiant zones to fix flow and comfort issues. Reliable Caleffi TwisTop thermo-electric actuators - which work flawlessly on the Rehau manifolds - were utilized along with 2-way thermo-electric zone valves to allow for easy manual opening of the zones to balance and adjust flow rate.
The boiler room piping was redone and a 2" Caleffi Sep4 was installed to eliminate air, dirt and magnetic particles that might be present. The removal of magnetic particles is extremely important in this system as it utilizes four Grundfos Magna3 circulators. Removal of magnetic particles is extremely important, I feel, especially in retrofit systems utilizing variable speed circulators. These circulators have permanent magnet motors on them, so we don't want any small magnetic particles getting into the circulators and building up inside and locking the rotor.
I utilized two Lochinvar boilers for added turn-down and redundancy. We lacked wall space, so we constructed a unit strut wall in the middle of the room to hang the boilers on. We hung the 2" Sep4 and system circulator between the boiler rack and the wall. This allowed us to keep the wall space for zone piping and controls. We mounted the Magna3 boiler and DHW circs on the backside of the boilers saving space and making everything very serviceable.
We also installed a 1-1/2" DISCAL air separator with insualated cover on the supply line of the indirect to make sure we eliminate any potential air issues since the fluid in this circuit doesn't flow through the SEP4. A Caleffi 132 Series QuickSetter was used in the indirect return piping to assure we maintain the correct flow for optimum DHW recovery. And - like every job - the bulletproof Caleffi 573 Series AutoFill combo was utilized for the boiler make up water.
The design goal of this home's heating system was to convert the home to natural gas while utilizing energy efficient products and designs to provide maxium comfort and savings.
One of the challanges of this job was how to get two 3" polyproplyne vents out the roof of the home cleanly and safely. We pulled the air for the boilers from the exsiting fresh air intake duct work that was used with the two oil boilers. This allowed us to run two 3" centrotherm InnoFlue flex vents up the exsiting 8" all fuel chimmney. We had a custom Stainless Wye built for a nice, clean installation.
The system has proved very comfortable and efficient.