Sunday, April 17, 2011

Burning wood for home heating.

Reducing our home heating oil bill has become a top priority. As we end our heating season and total up the expense for heating our home this past winter, the cost exceeded $4000. Included in this is an insurance "budget cap" that guaranteed we paid no more than $3.85 (I think) per gallon of fuel oil this year. We can't afford to pay by the fill so we sign up for a budget plan that estimates our usage, the cost of oil and splits it all into 12 monthly payments. When you sign up for one of these budget plans, in the small print, it tells you that the insurance costs an extra $149. per year. And this cost doesn't even include yearly service on our oil burner.

In an area with abundant wood, it makes sense to investigate burning wood (in multiple forms). The ideal situation would be to burn cord wood. Living in Maine, we have an abundance of wood and good folks that make their living from cutting and selling firewood. We ourselves have 55 acres of woods. So, for the cost of my labor, we ideally pay little for the wood we burn. For each of the options I investigated, it's important to calculate the payback period. This is the time it takes to "pay ourselves back" in savings vs. our initial investment. Any of these options requires operator addition of fuel. So, yes there's a bit more effort involved in burning wood but eliminating most of $4000. to heat our home (2010-11 costs) is worth the trade off.

Option #1: Pellet stove.
Pros- Easy to use. Minimal install (one, 3-4 inch hole through the wall).
Cons- Need to pay for pellets at $250/ton. Uses electricity. Weekly take apart and clean. Pellet stove can't heat whole home; maybe basement & 1st floor at most. Still have to burn oil. "Space heater".

Option #2: Wood Gasification Boiler
Pros- Would use existing hot water baseboard plumbing to distribute heat to whole house. Burns cord wood that we could cut off our lot = little cost for fuel.
Cons- Price tag starts at $7500. not including install & chimney. Requires electricity. Would have to build small addition to our home to keep boiler inside heating envelope. Couldn't afford water storage system that would increase efficiency of boiler.

Option #3: Wood Stove
Pros- No electricity required. Burns cord wood we can get ourselves.
Cons- Would have to install $2000. chimney which requires some interior remodeling and loss of closet space. May not heat whole home. May still have to burn some oil. "Space heater".

We've chosen option #3. Our financial resources are not unlimited and this was the most affordable option with the quickest payback. We've purchased a Vermont Castings Defiant. It was the end of the heating season and we received $280. off. This list price of this stove was about $2800. We have yet to get a quote on chimney costs and are comparing steel double wall vs. traditional masonry. We're estimating about $2000. for the chimney.

At our annual cost in 2010-11 of $4200 year, here are estimated payback figures.

Option 1: Pellet Stove (incl. vent kit) $2800. = 0.67 years*
     (BUT then subtract 5 tons pellets at $250. per year, $1250. per year and the cost of fuel oil, $2100.)
     (*this option may only reduce our heating oil expenses 50%)

 Option 2: Wood Boiler (incl. chimney, install) $12,000. = 2.86 years
     (may still have to burn some oil early in the morning and if it gets real cold)

Option 3: Large wood stove. $2660. + chimney $2000. = $4660. = 1.1 yr payback
     (may still have to burn some oil early in the morning and if it gets real cold)

While none of the options are ideal (what is ideal?) We feel investing in a large wood stove (this is the biggest they make) has the potential to reduce our heating cost the most.

A consideration. Both a pellet stove and wood stove are space heaters. They will be warmest closet to the appliance leaving cool spots towards the walls. So, we will add some vents between floors to take advantage of natural convection and also install a duct over the stove to take heat to the second floor.

I'll add more as things progress.

Friday, April 1, 2011

Reducing home heating costs.

Living in an area where winter is and the ground freezes solid for 4 plus months a year, heating our home is a major expense. According to my calculations, we spent approximately $4000. per year just for fuel oil to heat our 2000 sqft home and hot water (values have been rounded for simplicity). This was in 2010. Next to our mortgage, this is our largest single expense. As fuel oil prices will most certainly continue to rise (and my income most likely will not), I've been doing a bit of research and thinking about options to reduce our heating costs.

By far the most important, least expensive option when it comes to saving heat energy in the winter is insulation. Obviously, the most prudent thing one can do is to find ways to hold on to the heat one has. Insulation is a one-time expense and saves you money whenever  you move into the heating (or cooling) season. Insulation can be done progressively so the outlay of funds doesn't have to happen all at once. Insulation is something that can be done relatively easily by most homeowners. For all these reasons (and more), this is the most sensible place to start.

There are a few fundamental principles to consider when it comes to thinking about how to insulate (here comes the science teacher part). Heat energy always moves from an area of high concentration to low concentration. So, in the winter, if the temperature in your home is 70 and the temperature outside is 20, the heat in your home wants to escape to heat the outdoors. Insulation doesn't prevent the heat energy from doing this, it only slows it down. A second, less thought of consideration, is that the same principle holds for moisture. Moisture will also move from an area of high concentration to an area of low concentration. Water molecules are dissolved in the air and, as you know, water as a gas will turn into water as a liquid when it gets cold. This is something you obviously don't want to happen inside your walls. This is why vapor barriers are included as part of most fiberglass insulation.

The second principle is simply that heat rises. So, if your heat source is downstairs, the heat will rise gradually to the upstairs. Subsequently, cool air is more "dense" and will sink to the lowest part of your home. The combination of these two processes is called convection. There's many good images out there to convey the idea. Click here for one.

So, to best way to figure out how to approach adding insulation to your home is to think of these two concepts together and decide how the heat energy is escaping your home during the heating season.

One of the most obvious places heat energy leaves your home is through the windows. If your walls are 6 inches thick and your windows are 3/4 of an inch thick, this is a no-brainer. As much as 30% of a homes heat in winter may leave through the windows. Nice Fine Homebuilding article on windows here. Windows are rated in U-values. Insulation is rated in R-value. R-value = 1/U-value. So, even the most energy efficient windows with a U-value of 0.25 means that the R-value is 4. No matter how well they insulate, they are still holes in your wall that lose heat because they have less insulating value than standard wall insulation.

Consider that heat rises. So, even if you are conscientious, turn your upstairs thermostat down during the day (if you have one), the heat from the downstairs is going to migrate upstairs and leave through the windows. One of the most prudent things to do to your windows is, when it gets cold, add a layer of clothing to keep more of the heat in. For me, light is a necessity, especially in winter. So, while using a rigid insulation insert might work well for filling this "hole in the wall", it blocks out light. Not an option for us but may be for you.

Visit your local hardware or bigbox store in the fall and you'll see kits for seasonal window sealing. Frost King is the one I see most often. This stuff is nothing more than shrink wrap attached to inside window frames with double-sided tape. This is fine if you don't plan on using your window, accessing blinds, etc. and it is designed to be seasonal. I have found that the double-sided tape degrades and the plastic comes unstuck by the next heating season. A 3-pack can be found for as little as $4.00. So, if you have 12 windows to cover, it might cost you $16.00 to experiment next winter. Not a bad investment to investigate this option.

One of the things I've decided to do this summer is build light frames that will friction fit into many of our windows. These will be covered with shrink film on both sides. The idea is that they will act as an additional double layer of insulation. They will create a layer of dead air space between the two layers of plastic within the frame and a thicker layer of dead air space between the window and this inside "storm window". I'm not sure how long the film will last, how well they will store over the summer months and what mischief our cats might make but I feel it's an inexpensive solution and worth the experiment. I plan to use rough-cut lumber as we have a local sawmill in our area and buy a roll of industrial shrink with a heavier weight. I haven't found a low-priced source for this yet. Visit this post for an update!

The second thing I am doing is adding to and modifying the insulation in the ceiling above our second floor. R-30 insulation was used but wasn't installed correctly and was just loosely stuffed in to the spaces between joists.

We also have recessed light cans in the ceiling. Once in the attic, I discovered that these cans each acted as little chimneys that sucked the heat out of our upstairs into the unheated attic space. I have just completed building "boxes" out of 1.5 inch thick blue foam board. These surround and cover each light in the attic space. I caulked each joint with 30 yr caulk and "pinned" the boxes together with nails.

[On high density insulation board. Now, I'm not an advocate for using more fossil fuel products but, if their one-time use saves regular fossil fuel use in the long run, it makes sense to me in terms of cost-benefit.]

I'm also in the process of ripping blue board into strips that snugly fit in between the joists in the attic. This  high-density insulation is getting placed closest to our living space as it acts almost as a vapor barrier (technically its not) and, in a heating climate, this is where you want your vapor barrier. I'm also caulking these into place as the fit between the joists isn't perfect and I want to limit the heat/vapor permeation to the foam board.

On top of the blue board and between the joists, I'm adding R-13 fiberglass insulation (no vapor barrier) to fill in the remaining space to the top of the joists (white insulation in photo). The existing R-38 insulation will have its vapor barrier removed and will be placed in the opposite direction, over the top of the joists (pink insulation in photo). I'm hoping this will almost completely eliminate the gaps that exist in the insulation now and add to the R-value of this uninsulated space substantially. In total, the R-value of the attic will be almost R-60.

There are areas of the ceiling I am unable to get to without ripping something apart. But, I think that if you are approaching this kind of project, a certain type of philosophy has to prevail. "It's not about what you can't do, it's about what you can do that makes a difference".

More later as I complete this project and investigate interesting options for heating our home.