So we've moved out of our house temporarily to let the work begin in earnest, but we'll be back to the house on a regular basis to track the progress of the work.
Just yesterday we held an HVAC summit at the house to discuss the options for installing a new heating system to replace our current oil/steam system that is truly on its last legs. Our architect Olaf Vollertsen, energy consultant Marc Rosenbaum, HVAC sub-contractor Chris Conti, and our contractor Scott Sorensen all agreed on an all electric house with air source heat pumps for heating (and cooling if necessary), and an electric hot water heater (possible an air heat pump as well). Although electricity is commonly thought of as a more expensive energy source, Marc Rosenbaum continues to calculate that our costs will be more or less the same as with gas, based on it seems, the efficiency of current technologies and the cost it would take to retrofit existing systems.
The other major consideration we had to deal with, and perhaps the deciding factor, is whether or not to keep gas appliances in the house when it will be so tight. Marc told us that we would have to buy a new direct vent hot water heater to eliminate any CO leakage into the house, which would have cost just as much or more than a stainless steel electric heater. In the end, it seems worth it to eliminate all on-site compustion of fossil fuels. We'll also have to change from a gas stove and dryer but those don't seem all that difficult.
Our hope is to soon be able to install a PV system on the house to help reduce the grid electricity used significantly. Unfortunately our house has an east-west orientation, but we think we might be able to get a 1-2 kW system somewhere on the roof, providing us with perhaps 50-75% of our annual load, but this will have to wait.
We now wait for the HVAC sub-contractor to come back with a proposal for the entire system, including how to minimally duct for fresh air and heat, and what types of equipment we should consider. The current proposal is to probably duct to each of the 3 bedrooms on the 2nd floor and to the office and main space on the first floor. Less than ducting to every single room but more than we had originally thought. I think this is for comfort sake and seems to make sense.