Facebook reminded me that it has been seven years since we had our energy audit. Seven years since I retired. A bit over seven years since we purchased the house. The good news is that the property values have escalated, justifying the money we have put into the house. Of course the bad news is that we are not finished.
After the recent severe weather “Cyclone Bomb” on March 13, we have not regretted the expense for insulation, windows and sealing. Winds gusted up to 32 mph and were strong all day, plastering snow against the North side of all buildings and against even the South facing windows. But even without sun our house stayed quite comfortable with the daytime heat set at 65 degrees. And we are also insulated from the noise of the wind gusts. When we went out to the garage it was very noisy while inside the airlock entry we could see the extreme winds but the sound was muffled.
I decided to start a fire in the boiler fireplace for atmosphere as well as to help with the heating. The snow however had blocked the chimney due to the high winds! When I lit the fire the house began to fill with smoke. It was pouring out of the sealed fireplace. For a moment I was not sure what to do. Should we douse the fire with water? What a mess that would make! I closed the dampers which just made more smoke. We opened several doors and turned on the ERV system to clear the smoke. Then I went outside to check the chimney (in the snow and wind!) And since our roof slopes to the ground behind the house I was able to climb up to the non-smoking chimney and knock the snow loose. We heard it plop into the stove and the smoke began billowing out of the now open chimney. Whew.
So we had a fire in the stove after all. And with the bathroom exhaust fans and open doors and ERV running the house soon cleared of smoke and the fire alarms did not go off.
It was cold enough that the thermostats continued calling for heat but the boiler did not have to fire while the hot water was circulating from the fireplace. That was how it was designed and to see it working is quite a thrill. Sometimes when we have a fire it is not cold enough for a thermostat to require heat since our house stays so warm, so I have opened a zone valve manually and plugged in the circulating pump directly instead of letting the call for heat turn it on so that the warmed water circulates-usually to the rear radiators since that is the coolest area of the house.
This link is to the post with the last version of the boiler piping but I realized that it was drawn before I decided to remove the storage tank. We do not have enough fires to justify heating water in a tank instead of directly to the floor. Originally I removed it for the drywall install but I never put it back. This is the updated drawing of the current fireplace and boiler piping. It’s the 21st version!
Cold water flows from the pex in the floor and/or the radiators in the rear of the house, depending on which zone valves are open, through the heat exchanger to the gas boiler. When the fireplace boiler is not pumping there is no heat exchange. But when the fireplace boiler is warm enough and the secondary pump turns on, the warm water is exchanged with the cold water from the return, sending pre-warmed water to the boiler. If that water is warm enough the boiler does not fire. To prevent overheating in the fireplace boiler, a taco mixing valve adds cooler return water to the heated water when necessary. If there is not enough cool water, the fireplace boiler’s special low pressure release will remove excess hot water pressure to a stainless steel milk can that I found on craigslist and is just about the right size for the job. There is also a large expansion tank on the system to alleviate buildup of hot water pressure.
The best part about winter is our ability to avoid exposure to the high winds and bitter cold nights. The ERV provides very fresh air in winter although I don’t always remember to turn it on. Once I get the wiring figured out I will be able to manage the ERV more effectively. We also use less gas for heat and hot water than even our more efficient neighbors according to Xcel.