Night time lows below 35°F put the kibosh on energy savings!

This post concerns the effect of home heating when using a heat pump who’s T-Stat was been set down to 60°F for a home while a small 1,400 watt space heater was employed to heat just one room.

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It may be interesting to note that many heat pumps become quite inefficient whenever the outside temperatures fall much below 35°F. It’s at that point that many of these units switch over to resistive heating in order to warm a home. Please read the excerpt below:

“Heat pumps are only effective to about 35 degrees. Anything lower than that, and you have to use your emergency heat. The two reasons for this are that when the outdoor air temperature gets too cold, the unit cannot extract as much heat from the outdoor air to keep up with heating demand.

Second, condensation forms on the outdoor unit when it is running. In temps above 32 deg (freezing point of water), the condensation simply drains away from the unit. Below 32 deg the condensation freezes to the coil and blocks air flow. When this happens, the unit must go into defrost mode to clear the ice. During this time the heat pump is not heating your house. It’s heating the outdoor unit to clear the ice.”

So, at about 35°F, your heat pump also switches over to a set of resistive heating coils located in the inside furnace. This form of heating is much less efficient and power consumption can soar. My heat pump is a two stage heat pump which can even be less efficient as will be explained below:

“A single stage heat pump uses the same rate of transfer at all times during operation.  A dual stage (also called a 2-stage), uses 2 different rates of transfer.  Put simply, these 2 stages are kind of like a “high” and a “low”.  When the desired temperature and measured temperature are fairly close in number, the unit will not need to work as hard, thus using the “low” setting.  In this case, a low rate of transfer is all that is necessary for getting to the desired temperature, so why push it and use more energy than is necessary for the job?  Conversely, when the difference in temperature is high, and the unit needs to change the temperature several degrees quickly, the dual stage heat pump will switch over to the high rate of transfer and more energy will be used to get the job done.”

This ability to go from a low setting to a high setting simply means that at the high setting, my house will get warmed more quickly. Useful if it’s really getting cold outside and the unit is struggling to keep up. However, not so good from an energy consumption standpoint!

Let’s see this from the standpoint of actual data. Below is a graph of what happened to the outside temperature during the night of November 17-18, 2012. As you can see, at about midnight the temperature dropped into the freezing range (yellow area of graph).

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 Correspondingly, the heat pump began to kick on into Stage 1 (note it never made it to Stage 2 due to both the low setting for the house proper and the fact that it never got seriously cold outside).Let's now look at the corresponding power graph for that period of time as measured by my TED energy monitor:

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All those little spikes represent my small space heater kicking on and off all night long. In spite of how it looks, this little unit did not consume much power as it was heating just a 1600 square foot area (my bedroom). The stage 1 spikes were indicative of the switch over by the heat pump sensor to relatively frequent bouts of resistive heating (5 from 12 midnight to 8AM). Once again, my low thermostat setting for the rest of the house combined with the fact that the lowest low was 27°F. is really what saved the overall situation. Had I been trying to heat the entire home using just the heat pump, the situation would have been much different. Now, take a look at the actual power consumed both before and after the mercury dipped below 35°F.:

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Wow! There was roughly a 50% increase in the amount of energy consumed (all things being equal) after the drop below 35F. I also noticed a residual effect as the house, once cooled, was reluctant to come back up to a 'normal' reading of 60°F.

Disclaimer: There is no way that the information present here could be construed as scientific. It was presented honestly but be forewarned that the author has absolutely no credentials in the areas of heating and cooling.

My winterizing efforts for the 2012-13 winter season!

It’s October and nobody has to tell me that winter ain’t too far off! I’ve already noticed that some of the trees around my house are turning and every time I look out back, there are more of them lying on the ground. So, I got up off my butt and began to look at how best I could get the old homestead prepared for the cold months ahead.

The way I see things, when all the dust settles, there are two issues that have to be addressed for any all-electric home like mine; 1) how much money can I save on heating and 2) what amount of comfort will I have to give up in order to save on said heating? (Both these concepts are certainly at odds with each other in that if I keep the house warm all winter, say at 72F or so, I then get hit with large monthly electric bills). This going on at a time when I’m on a fixed income and slowly going broke. If, on the other hand, if I elect to freeze to death, I’ll save a few bucks to put towards my funeral costs. Either way, it seems to me a lose-lose situation.

Yet, there are some alternatives out there and they don’t have to cost very much. Here they are in no particular order:

Kill those Drafts

Almost any old house has what I call leakage. That is, air that come and goes through cracks either in the structure of the house itself or through various openings around holes through which plumbing pipes enter or exit the house. A can of foam costing about $6 bucks took care of those in short order. Weather stripping also works great to help seal outside doors!

Corral that Water Heater

Two simple things can be done here to lower your heating bill as much as 10%; 1) set the t-stat to 120F and 2) wrap that sucker in insulation.

Lower the Thermostat a few degrees

Some expert once told me that for every degree you lower the thermostat setting, expect a 12% savings in your monthly electric bills! I’m not sure if that’s the truth or not and would guess that there is probably a lower limit after which you really wouldn’t save and still freeze to death. This year, I’ve opted for a setting of 65F for the majority of the house with a small space heater to use for my office/bedroom. Oh, and an electric blanket also helps tons!

Manage those blinds and drapes

No matter what sort of window covering you have, keeping them open to let the sun in and closed at night to keep the cold out makes sense. You can also elect to use one of those plastic shrink wrap coverings like those sold by 3M. They can increase the R-Value of that opening by as much as 90% by creating a dead air space between the cold window surface and you.

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There you go! That was pretty simple and it didn’t cost an arm or a leg to implement. I hope to do some additional postings as I go through the winter months to see if any saving actually materialize. Oh, and I'm hoping Global Warming really kicks in too, this year!

LED light bulbs make cents!

 At some juncture, while looking at ways to winterize my home and make it more energy efficient, I got to looking at the light fixture by my bed. As is my habit, I like to read in bed and so inevitably leave the light on after I fall asleep. So, the light burns night after night for about eight hours. It’s a regular 60 watt incandescent bulb as opposed to a CFL light bulb which I found can cause skin cancer when used close to the body. Over time I found that this little bulb, being on every night, could cost around $18 per year to operate. Not a great savings, that’s true, but if there’s a cheaper alternative I'm all ears.

Enter the 40 watt LED light bulb from a company called Hitlights. An alternative light source that costs about $11but which boasts a 40,000 year lifespan! (That’s about 13 years if I were to use it 8 hours a day). And, at only a power consumption level of 6 watts (.006 kWh), that would bring the cost down from $18 for a 60 watt bulb to about $2 over the course of a year. Not a bad savings in my book! So, what’s the downside?? – In a word, color. This bulb’s color rating is 6500 K – which puts it more toward the blue end of the color spectrum when viewed by human eyes. (Note: for $18, they also offer a 75 watt bulb that uses 9 watts of electricity, but which is much closer to a regular incandescent at 2700 K). Will that work for a bedside lighting source? I’ll update this post when it arrives sometime in October.

Update: Hold the presses! My light came recently in the mail and when I installed it I was amazed at how good the light looked!  Here. Judge for yourselves....This photo was not altered in any way and shows just what the light looks like.

My 2012-13 winter power goals!

Let me set the record straight! Last year's winter was pretty darn mild. And so were my electric bills when compared to the year before. Over the four month period November through February, I used 4,066 kilowatt hours of electricity to run and warm my home. That was 2,639 kwh less than the winter season before and represented a 39.4% savings in hard cash! Yowser! This year I'm hoping we have yet another warm winter thanks to Global Climate Change. (I think the odds makers are saying we have something like a 34% chance of a plus 3 degree winter over the norm). If that comes to pass and along with other improvements I've made, I'm hoping for a drop yet another 25% off last year. In real terms, that would be about 1000 kilowatt hours less over the four month period and would represent one heck of a drop when you average the past two years out!

I'll post updates on how well I'm doing after the winter season gets underway.

Energy saving comparision for 2010 versus 2012!

I finally go around to tabulating the results of my energy savings program’s effectiveness for the year 2010 compared to 2011 when many of the changes were put into place. I think it is apparent that this program was successful and I hope to continue to explore other ways to save a watt without sacrificing comfort or convenience!

January 2012 – Another great energy month!

Actually January was a great month for me, energy wise, not so much because of anything done on my part, but rather due to the relative warmth. January was over seven degree warmer than the average and that play very well when it came time to pay the electric bill for the month.

In 2011 my bill was $182, and this year, it was all the way down to $121! That’s actually a thirty plus something savings as my rate was increased 13% this year versus last. Now, with the weather forecasters anticipating a warm February, I’m hoping to have done rather well for the entire winter season!

December can be a tough month on the wallet!

Last December, I used 1,629 kilowatt hours of power to keep my home warm and to run my assorted appliances and electronic gadgets. December 2010 was a perfectly normal month from the standpoint of outside temperatures. The mean was 35.1F versus an historical average of 35F. That translated into an average daytime high of about 45F and a low somewhere below freezing. I own a heat pump and as you may know, they struggle to work at any temperature much be 32F. So, for most of the month, the ‘emergency’ mode went into effect whereby heating elements were turned on to make up for what the heat pump could not provide.

Last year, however, I made some changes both physically (installed plastic over the windows) and in terms of how I used power. I employed the aid of a device called the Total Energy Detective (T.E.D.) to help me monitor my power us real time. I also set a budge of no more that 52 kilowatt hours of power per day and that worked out pretty well. Whenever I could, I would avoid appliances like the stove in favor of the more energy efficient microwave. I used space heaters deployed in select rooms to facilitate point of use heating. I made sure to run my dishwasher less often as I did the washing machine (no more partial loads of laundry). I was on a budget and I stuck to it!

The end result was a 34% savings in 2010 over 2009! That lower electric bill was a real blessing during a month when all my other bills were high! Now, this year, I’m hoping to improve on 2010 and have reduced my electric budget by another 25%. That translates out to 52-13 kWh less power a day or about 39 KWh. If I get lucky this coming December will be a little bit warmer than the average of 35F. If that happens I’m sure I can make this work. Otherwise, if it gets colder than normal, I’ll certainly have a challenge on my hands.

If you’re wondering how I did for November 2011 – it was a 34% decrease!