Just Hover your mouse pointer over the 1m (1
month) 1q (1 quarter) 1y or 5y hot zones and the chart
will display the history over that time span.
By clicking on the image you will be leaving Video Interchange and directed to the information source !
One question some folks have, is why the prices change even when the US markets are closed ? Answer: oil is traded globally around the world, not just in the US market. Monday thru Friday is only a US concept. World markets for the most part are 24/7
As a very rough rule of thumb to determine the gasoline pump price, divide the cost/barrel of crude by 44, then add one dollar..... You will find it amazingly accurate !
Why ? - the cost of refining ,distribution, local station markup has been stable for the past near 50 years. It amounts to about a dollar spread.
For example: If a barrel of crude is $135 then 135/44 = 3.09. then add $1.00 for a pump price of $4.09/gallon. As crude increases, it won't be long before you will see it reflected at the pump !
To solve for crude price at a given pump price, just reverse it.. Take for example a $5.00 pump price, subtract $1.00, then multiply by 44.... $5.00 - 1.00 = 4.00 x 44 = $176.00/barrel.
Local pump prices vary from area to area, but this little rule of thumb will get you real close to the national average.
The current average delivered Home Heating Oil price in the
Midcoast area is $2.17/Gallon as of 1-3-2009
Energy saving tips (How to survive the cold Maine Winters)
For years, my first company (Air Image Technology) specialized in energy conservation. We employed an Inframetrics scanner, Barnes Engineering "Insta-therm", as well as state of the art thermographic imaging & data capture techniques for the time. Our client list read like a "Who's Who" of the top fortune 500 companies, including the US Govt, American Petroleum Institute (all the major oil companies) and local energy suppliers ie Con-Edison, Mass electric, Boston Edison and many of the commercial high rise buildings from Boston as far south to Atlanta and west to Chicago, to name but a few.
What we learned from all of those surveys, tends to go counter to much of the "hype" put out today by industry and even our own Govt...... The mantra chanted by both is to insulate ! All well and good, but infiltration/exfiltration losses are rarely ever mentioned or given the attention they deserve.
The reason why there is little mention of infiltration/exfiltration losses and how to reduce them for little or no cost, is the reality that there is no large profit to be made in simple things a homeowner can do that has the potential of literally cutting in half his home heating bill. The real $ to be made is in selling insulation, windows, heating systems and the like..
What is infiltration and exfiltration you're probably asking ?
Infiltration: Cold outside air entering (infiltrating) the living space though a void in the building envelope.
Exfiltration: Warm air exiting (exfiltration) the building envelope thru a similar opening or void in the building envelope.
I've written this in non-technical terms about as simply as I know how...
Infiltration - Exfiltration Losses
Don't read the following wrong... Adequate insulation is also very important. But FIRST, consider the following.
Insulation (or lack thereof) is RARELY ever the main source of energy loss in most residential building envelopes. In almost all instances, losses due to inadequate insulation ranks a far distant second. Rather, in most cases and especially in residential structures, infiltration losses (literally due to "holes" or voids in the structural envelope) account for the lion's share of energy loss. Having R-30 insulation throughout one's home will be of little benefit if your building envelope leaks warm air like a sieve. To put it in more understandable terms: you can have one of the warmest Goose Down Mountain Expedition Class Parka's suitable for the extremes of Mt Everest or K2, but all it's state of the art insulative properties will be in vain if one doesn't "zip it up" and one leaves it wide open to air infiltration... Don't believe it ? Then next cold winter day with just even light winds, venture out in you warmest winter coat, but this time, don't zip it up and add some spacers around the wrist cuffs to allow cold air to infiltrate up your arms. You still have the same exact amount of insulation .... Only now, it's not doing much good. ( I rest my case )...
Likewise, all the insulation in your walls and ceiling will be rendered near useless if you leave open all the doors and windows.... and the amount of thermals losses through just a single 12x30 inch area can be huge ! (Most homes (even new construction) have far more than this total area by the time all those little "holes" or voids in the building envelope are added up !)
Next cold blustery day, try opening a window about 12 " on the windward side and feel the effect for yourself. It's pretty much a given that your heating system will be struggling to keep up with the infiltration losses just by this one open window. Conduction/Radiant losses thru the walls or ceiling will pale by comparison.
How to check for Infiltration - Exfiltration Losses
The more severe trouble spots are easy to locate: such as moving curtains on windy days.... Most others are not so easy to locate... Here's how to find them....
There are all kinds of fancy (read: expensive) quantifiable equipment employed by professional energy survey companies. Don't read me wrong - I'm all for being able to quantify (measure) the losses and made my living for years by being able to do so. But this is for the struggling home owner that hasn't a spare $50k to blow on test equipment or posses an engineering degree in thermodynamics... In this case, you don't need to quantify the data - only to know if you have a significant infiltration problem and then identify the sources. To do this yourself requires but a few pieces of inexpensive "Test Equipment", which you probably already have.
One - 20 inch or larger window fan. The "bigger" and more powerful, the better !
One - Small roll of Duct Tape
One - pack of cigarettes, "punk" fragrance burner or other small smoke sources
A sheet of cardboard you can cut to size
One utility knife
Total: $30 - $50 or so at Wal-Mart, assuming you have none of them. (You will easily win back that amount in just the first month of heating season in fuel savings alone !)
Somewhat more pricier than a fragrance stick is a professional smoke generator, known as a Smoke Stick. Retrotec makes one (About $55)
Begin by placing the window fan in (you guessed it) a window, so that the fan blows outside air into the room.
Next, cut the cardboard to block off air flow on either side of the fan to inhibit any easy possibility of air escape. Duct tape the Cardboard to form a reasonably tight seam.
Next, open all inside doors yet tightly close all exterior windows, doors, storm doors etc leading to the outside. If you have a wood or coal stove, then fully close the air control.... In theory, you now should have (supposedly) an air tight building envelope.
Turn the fan on "High". If after 1 minute, if a strong inflow of air is still evident, then you have a major infiltration / exfiltration problem...
Why you might ask ?
All that infiltrating air blown in by the fan has to be escaping somewhere, otherwise the house would explode (assuming the fan was strong enough to compress the air sufficiently to cause structural failure). In reality, even the largest window fan would simply not have the power to move any air, due to the backpressure buildup. Once pressurized (assuming minimal exfiltration) the window fan would be working against the increased house pressure and little air would be "fanned" in.
The fact that a major flow of air is still entering the house after several minutes means the same volume of air has to be exiting somewhere thru "holes" in the building envelope. That's the concept.... In other words, you try and pressurize the house and then see what is still capable of coming in. For auto/aviation mechanics, the procedure is similar to conducting a leakdown test on an engine cylinder. What still comes in, has to be what is escaping somewhere.... The influx of air after max pressurization is achieved, then accurately represents what exfiltration losses there are. (exfiltration just being infiltration in reverse - depending on the direction of airflow...)
Even more simply: if it's still coming in at a good clip after a minute or two, then it has to be escaping somewhere (at an equally good clip ! )
Your home Barometer as an infiltration gauge:
If you have a interior home barometer, note the barometric pressure inside before pressurizing / de-pressurizing. The greater the deviation from the first reading, the greater the "tightness" of the house !
(and all the time you thought it was useful for only predicting weather trends !)
Note: An energy audit company will use a manometer which is a highly sensitive instrument for measuring differential air pressures. That combined with a calibrated fan and being able to measure the volume of air, will enable one to quantify the infiltration/exfiltration losses.
A far less scientific approach but also a good indicator, is how soundproof the structure is ... Tight building envelopes with adequate insulation, tight windows/doors etc, will be quite soundproof. On days of howling frigid winds, a tight building envelope will be quite soundproof... There should be little audible evidence of the winds outside
How to find / Locate Infiltration / Exfiltration Losses
Now that we've determined the house to be a heat sieve, the next step is to locate the source of the troubles.
Locating air leaks from the outside with varying ambient winds is very difficult if not impossible. (remember, for the first test to identify whether we even had an infiltration/exfiltration problem, meant we pressurized the building envelope and then waited to see what air must be being expelled to maintain a constant airflow).
However, it's much easier to locate the leaks by instead de-pressuring the house on a calm day, and seeing where the outside air infiltrates in. To do so, merely reverse the direction of the window fan so that it exhausts the air. This now de-pressurizes the building envelope. The fan should now be expelling the same volume of air as must be leaking in.
Now a simple matter to use smoke as a diagnostic tool working from within the home to locate the infiltration ! (Kind of like a "smoking gun" sort of thing).
Common Sources of Infiltration / Exfiltration Losses and other considerations
The most common are obvious: Poor fitting window & door seals / weather stripping. So easy to find & so self-evident, I won't even dwell on them.
Some of the less obvious however, can be "Gi-Normous"..........
Fireplace Dampers..... often the #1 loss !
After a romantic evening fire burning in the fireplace, the next day after the fire has gone out (maybe both of em - but that's another topic & not covered here) the homeowner (usually the husband for reasons not yet undetermined) forgets to close the fireplace damper the next day... The opening in terms of square inches is equivalent to a fully opened casement window. That is doubly compounded by the fact that the entire structure is designed as a chimney... (after all, it is a chimney !) That is: for the sole purpose of exhausting interior warmer air efficiently as possible to the outside. One would be hard pressed (short of placing a fan in an outside window in the dead of winter) to more efficiently expel interior heat ! Thus one left open chimney damper can easily account for the thermal effect of leaving fully open two casement style windows.
What most people find very surprising, is that there's little immediate sense of localized cold. Warm interior air passes by the person, so he has little sense of it, and exits up the chimney. The heating system merely struggles to make up for the huge losses (naturally at great expense)....
Even if closed, check the seal. Debris has a way of falling on the seating face making for a poor seal.
One open fireplace damper left wide open can easily account for $500 or more in energy losses in a typical Maine home at 2007 oil prices....
Furnace air balancer/barometric damper: Most chimney flues use an air balancer to allow a cooler mix of air with the hot exhaust gasses to stabilize the draft. They are normally a 6 to 8 inch weighted damper located just above the furnace. With the furnace off, the damper should be visually fully closed. For whatever reason, furnace servicing technicians rarely seem to check for a jammed open one. Though rare, neither do they last forever...
Range hood exhaust vents. Normally most have a gravity damper. When the exhaust fan is on, it has enough pressure to force the damper open to expel the fumes. Once the fan is turned off, the damper closes by gravity. Like everything else, they don't last forever... Unfortunately, they can jam open.
Excessive Back Drafting is usually a symptom of this one, where the entire house itself behaves as a chimney for a major exfiltration problem...
The problem exhibits itself with back-drafting into the house itself. This is because the warmer air in the lower part of the living area , now has a clear exit path usually via the roof or attic. It creates in itself, another chimney effect which is a most effective method of expelling lower warm air to the colder outside.
Most common source is poor living space air tightness / sealing with the attic and roof. Unless visually apparent, it's normally due to a poor sealing attic access hatchway. The chimney effect once started, can be dramatic, and it doesn't take much of an opening to get it started... Exasperating the problem, is that the greater the difference between interior an exterior temperatures, the far greater will be the chimney effect.... (The 2nd fundamental law of thermodynamics)
Though not a heat loss per se, improperly adjusted air balancer dampers in hot air system ductwork, can ratchet up significantly the energy costs. Simply put; the bulk of warm air flow should be directed to the main living space. A penetrating glimpse of the obvious perhaps, but often overlooked. There are many automated diverter/dampers that can be programmed for example, to increase warm airflow to rooms only when needed.
Stratification: Simple fact that heat rises. Thus high ceilings such as entrance foyers can result in significant stratification where the much warmer air becomes naturally trapped close to the ceiling. The higher the ceiling: the greater the problem. Even for a standard 7 to 8 foot ceiling, a 15 deg f difference between floor & ceiling is not unusual, and all that nice warm air trapped close to the ceiling (you paid dearly for) does little for your comfort level. That warm bubble of air might as well be on the other side of the planet ! For most folks, they just notch up the thermostat to compensate for the stratification. A simple parlor type fan in most cases, will re-claim that heat by circulating it down to the living space, and will often save far more in heating costs than the electricity required to operate it.
Multiple floor homes also can result in moderate to severe stratification where the upper floor(s) are too warm, while the heating systems struggles to maintain comfortable temperatures on the first floor level. In the case of forced hot air systems, this is due either to improper air balancing (see #4 above), or more often times due to a poorly designed (or sometimes even totally lacking) return air system.
Wall Plugs: Purchase some wall plug foam at your local hardware store to stop any infiltration/exfiltration losses around the wall plugs.