Hello everybody. My wife and I just bought our first home, a 3BR/2BA 1.4K sq ft ranch with an attached garage built in 1973. This property has obviously been through a succession of homeowners and is a bit of a frankensten at this point. It is structural sound, and all of the primary systems are in working order (although a few, such as the roof and the heat pump are nearing the end of their lifecycle and will probably need replaced in the next 3-5 years).
My big concern with the property at this point is energy cost. During the first weekend we moved in, I happened (by chance) to notice the electric meter roll 100kWh over the course of 10 hours or so. I immediately went to Lowe's and bought a programmable thermostat, and also some insulated flexible duct to repair a broken AC in the attic.
This attic is a nightmare! The roof is supported by low-rise trusses 16" on center, so it's very difficult to move around. There's about 5 inches of loose-fill blown-in insulation over most the living area, although it is not evenly distributed and some of it has been completely removed.
The attic is ventilated (sort of) by a fan installed in the south gable. I've noticed that this fan run at least 16-18 hours each day, but I'm not convinced that it's doing much good.
After installing the new thermostat and repairing the faulty ductwork, I started tracking the electric meter on a spreadsheet every day. Now I'm averaging about 48kWh usage per day, which equates to about $135 per month (the rate here is about $0.091/kWh during summer months). This is an decrease of about 30% from our last residence, so I fell as though I'm making some progress.
I understand that I need to caulk up every opening from ceiling of the living area, and essentially make the living area as airtight as possible. I'm concerned that I do not have enough insulation in the attic, and that the attic is not ventilating properly.
These are my questions:
There are two vents (kitchen and bathroom) plus a woodburner that all have vent stacks through the roof. We don't intend to use the woodburner at all and plan to eventually remove it (and the brick pad it sits on) to reclaim the living space in the den. Is there a way to put some sort of damper on the two vents and also temporarily seal the woodburner flue? I'm concerned about thermal transfer, but maybe I'm worrying just a little too much.
From what I've read, I need to install about 12-18 inches of insulation. I would much prefer to use batting instead of loose-fill, namely because I can more install it myself. I'm also attracted to the idea that batting will stay where I put it and not "wander around." Can I install batting over the existing loose-fill? I realize that the batting will probably compress the fill and reduce its effectiveness, but can I offset that with the thickness of the batting?
Sometime in the next few years, we will need to replace the the roof. I've heard that ridge vents are more effective for attic ventilation than fans. Is there any energy cost advantage to installing the ridge vent now (and sealing the gables), or should just wait until we have the roof replaced?
Speaking of replacing the roof, what is the best material to use (we have asphalt shingles now)? My wife is pretty interested in a metal roof, because it will presumably reflect radiant heat during the summer. What's the general opinion here?
Finally, I'm curious about low-e window film to install on the existing windows (which are large aluminum frame single glazing). The windows themselves are in pretty good shape and are well-sealed, but the front of the house faces west and gets a pretty tough dose of the south Georgia sun every day. Is the effort it would take to install this window film on 170 panes of glass going to be rewarded with any real cost savings?
Sorry if this was a long drawn out post, but it essentially all revolves around trying to lower my energy costs. I sure do appreciate any comments anyone can provide.