Air sealing, vented vs. non-vented attic, and a new HVAC system possibly in the attic
My husband and I were hoping to get some unbiased information related to our first major home renovation project.
Our Goals Are: Air sealing, updating our attic insulation, and installing a new 2-Zone HVAC system plus ductwork in a complementary and cost effective way.
Our Home: colonial style house built in 1980, 2 floors plus basement, 1800sq ft + finished basement, vented attic with attic fan, no ridge vent, soffits on front of house only, existing insulation is on attic floor that is the same age as house – rolled batt fiberglass, 4/12 Roof Pitch, no existing duct work.
Located in Maryland at the very top of zone 4A, bottom of zone 5A.
We had a blower door test done and found the house is very leaky, mostly from the attic into our 2nd floor. The contractor recommended that we air seal and add 15″ of blown in fiberglass insulation to the attic floor before doing central AC. The HVAC contractors recommended putting the air handler and duct work into the attic. To us it seems doing the insulation first will make the HVAC contractors work much harder.
We are also concerned about putting the air handler and ducting into an unconditioned space. We read about the loss in efficiency, sweating, and higher energy costs and started to research a vented vs. non-vented attic space. Doing a non-vented attic seemed like a good idea at first but then we became concerned with the health of our roof (ice dams, moisture issues) and the cost of the project.
We have discussed putting the air handler into a closet on the 2nd floor but there doesn’t seem to be a way of retrofitting the duct work without using the attic space.
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