This cold snap has got everyone (including my wife) talking about HVAC and their comfort. Our 10 year- old home has fiberglass batt insulation in the walls, and blown in fiberglass in the attic. The sealing of cracks and penetrations wasn't too high on the builder's priority list - we have a lot of drafts. Our heater is natural gas-fired, but it only has one zone for the three finished levels. Needless to say, I have a fairly dramatic temperature gradient between my basement and my second floor, and when combined with the draftiness, my home isn't exactly comfy cozy.
When we are building a new home, making a tight envelope has become our standard, and it's really quite easy. You need to pay close attention to detail, but its not rocket science.
Designing and installing proper ductwork is another story, and it has actually become one of our most challenging parts of the build. Part of the reason is very nature of custom building, and the complexity of our homes doesn't help.
In the past, residential HVAC contractors often showed up on site and just figured it out as they went. If we simply use TJIs, bulkheads are inevitable.
And if there was a beam in the way, they would have no choice but to put in a "jumper" and drop the duct down. Like this... (note: this is NOT one of our projects)
To the rescue is Open Web Floor Joists. If designed properly, this type of Engineered Building Product allows our installer to route all ductwork without the use bulkheads. This save space in the home, and provides a much cleaner look to the space.
We are currently building a custom home on Denton Road in Bethesda where we are using these type of floor joists. Below are a couple of pictures....
Of course, this type of detail requires a lot of communication between the designer, engineer, our panelization company and the HVAC contractor. But the upfront effort pays off in a cleaner design, tighter ducts, and better overall HVAC system performance.
