September 24th -- Fall has arrived; the days are growing shorter, the nights are getting colder and I'm ready to bring on the heat.
The work pace has slowed a bit and it is now all about getting the "subs" to finish their part of the project. The heating contractors are working away to install what is a relatively complex zone-heating system. Complex in the sense that there has been so much new construction in terms of walls and rooms, that they have to design where the heating vents will go. A tricky part of this is that there are three rooms on the upper level of the original house that have heat registers in the ceiling and the heating ducts have to go through the attic, where there isn't much space for the crew to do their work. These photos illustrate the challenge:
This is the "hole" in the upper-level bathroom that heating ducts will need to travel from the basement.
At the top of the "hole" you can see furnace venting that will travel through the attic.
This is the "old" furnace, a Lennox circa 1970s...
The "trusty" Lennox furnace used to be positioned here:
And the new, Bryant 92% efficient furnace has been positioned in its place, along with the control box that will run the vacuum system that will operate the dampers for the zone system (more about that in a bit).
The new heating system will have four zones -- old house, new house addition, upstairs, and downstairs. The zones are defined by the duct work.
Here are a few shots of the duct work as it comes off the new furnace and travels across the existing basement to the crawlspace under the new addition.
One of the challenges in heating the house is that the original house outer brick wall and lath and plaster wall construction is rated at R 7 (the R-value is the measure of thermal resistance -- the higher the number, the better the insulation) and the new house construction will be rated at an R-value over 20. The building codes here require that for the section of the roof where there is no attic, the R-value must be 38 (foam insulation will be shot into the space between the wallboard and the roof rafters). So, the challenge is to heat the "colder" parts of the house (R 7) without baking the "warmer" parts of the house (R 38). The most energy efficient way to do this is by using a zone heating system.
A zone heating system divides up the entire house into different zones and each zone is controlled by its own thermostat. Since there is one furnace, the challenge is to control the heated air that travels through the ducts to the different zones of the house. Since this is a forced air furnace, one way to control the heat through the different zones is to use dampers in the vents to increase or decrease the flow of the heated air.
Zone heating systems have been around for a while, but most have used motorized dampers which are prone to problems - the more moving parts, the greater the chance for a moving part to fail. To avoid these problems a vacuum system is being installed in my house. Each zone will have its own thermostat. Each thermostat sends a signal to the furnace and the furnace heats up and turns on the blower motor to circulate the heated air. The signal from each thermostat goes to an electric control unit that uses the vacuum system to open or close the dampers in the vents.
Here is a photo of the damper mechanism that fits in the venting. As shown below, the damper is positioned in the "closed" position so that no or very little heated air will travel through the venting.
Here is the damper mechanism in the "open" position so that the maximum amount of heated air can travel through the venting. The dampers can also be positioned in between the "open" and "closed" positions as shown in these photos.
In the photo below, you can see the little "nipple" where the vacuum hose will connect to the damper mechanism to control the position of the damper in the vents. The design is very simple, very few moving parts, and much more reliable than damper systems that use servo-mechanisms or motors to position the damper to control the amount of heated air that flows through the vents.
This will be a four-zone system. There will be one thermostat or zone for the upper-level master bedroom and dressing area (the master bathroom will have radiant heat under the tile floor so there won't be cold tile floors). A second zone will be the upper-level bathroom, bedroom (that I use as a home office) and sitting room. The third zone will be the original house main level foyer, living room, dining room and guest room/bath suite. The fourth zone will be the kitchen, laundry room, gathering room addition, mud room/rear entry and main level bathroom.
The framing crew is down to two guys who are doing "mop up" -- which includes finishing details. The door that leads from the upper-level master bedroom to the covered deck was installed today, as shown below.
The photo below shows the new door as well as the framing for the fireplace that will be installed in the master bedroom. This is a steel door that has a blind inside the window panel that I can adjust as this is a west-facing door.
The framing crew also installed the siding to the back of the house as well as the cedar shingles that you can see above the siding (starting above the windows). The siding and the shingles will be painted when the entire house is ready to be painted.
The mason is also back to install brick around the foundation of the addition and on the west side of the new addition where the new fireplace will be installed. This brick will tie the design of the new construction to the brick of the original house. In the photo to the right you can see where that the brick will be laid up to the soffit (below the covered deck) for the fireplace for the gathering room addition.
With the shorter days and cooler nights, and no functional heating system, the main way to "warm up" in the morning is the old fashioned way....jump into a hot shower. The average first frost in these parts is in about 2.5 weeks, and the first snowfall could happen anytime. It is almost time to set up the down sleeping bag in the alternative sleeping arrangement!
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