You are currently browsing the category archive for the ‘energy projects’ category.

After YEARS of thinking about it I finally purchased one! So what did I buy. I really wanted the the between the truss system by Century Homestead.  But I had a few problems with that system. First was cost. After tax and shipping, it was going to cost close to $1100. That is a lot of bling! Second, I am the only one that is going to install this. No one is going to help me. The thought of man handling a 78 lbs fan through a very small opening did not sound like my idea of a good time. Next, installation. I am sure I could have handled it fine but for that kind of money I could have something installed by someone else. (That thought still sounds great but I do like the DIY thing, just not as much as I used to.) Having to frame and seal everything is just too involved. Last, this is a big one, free venting area inside the attic. I have tried to calculate my free vent area and I can not be sure I have enough for the 30″ or 36″ fans. I have a ridge vent and soffit vent system. I can easily get the ridge vent number, it is 5 sq. ft. But the soffit vents, that is harder. Common sense tells me double the ridge vent number. That would mean a balanced system but I can not be 100%. This means I have just enought vents (10 Sq. ft.)  to run the 30″ 1/3HP fan. While not bad, it would still cost about $950 and not be equal to the 36″ 1/2HP fan.

So, I decided on the QC 2250. Cost was $550, shipped and it comes with a wireless remote. It moves 2285 CFM of air as compared to 7600 CFM from the 30″ 1/3HP traditional whole house fan. One person reported 3000 CFM, so we will see. The grille size is much smaller, 16″x20″. The other grille 24″ x 38″ The unit should be as quite or quieter then the traditional whole house fan route. Installation should be easier and quicker. The really nice thing is, if I like the unit and I think adding another would cool the house even faster I can just buy another . I would place that one in the hallway between the kids room.

Now, I will have to modify how I use the fan since it is smaller. The plan as I see it now, is to cool the two kids room first by only opening those windows. Then after they are asleep, close them up and open the master bedroom windows. After the master is cooled then open the basement window and let the basement, first floor and second floor cool all night long. Shut the house up in the morning and do it again the next evening. I will post my thoughts and feelings after I get it installed.

But this does have me thinking about a solar attic fan. I think that will have to wait until I replace the furnace with a heat pump. Then the furnace chimney will come down and the solar attic fan can fill the hole in the roof. This will then at least another foot of venting free air. (after the sun sets anyway.)


In my last blog I said that I broke down and purchased a small generator. After some digging on the internet, I found that the power output from these generators is very “dirty”. Sensitive electronics would not like it at all. So I have a solution. Sometime ago I purchased a used APC Smart-up 1500 on the internet. It has the ability to condition the incoming voltage. Basically, it does a great job at making the output stay at 120VAC. The idea is to run the generator and have it feed the battery back -up. The battery back-up runs my emergency loads. With a load of 300Watts the battery back-up will last close to an hour. That would be enough time for the generator to cool off and I could refuel it. Since my emergency load should be very small. (100W) I could get over three hours with the battery back-up.

So I would say it is the middle of winter. Maybe not by the calendar, but the thermometer says so. From my observations, the electricity usage for the hot water heat pump have increased from 3.33kW hours to about 4kW hours per day on average.  This increase can be attributed to three factors.

  1. The incoming water temperature has decreased because of colder ground temperatures.
  2. The heat pumps ambient air temperature has decreased.
  3. The shower “anti-scald valve” has caused me to increase the tank temperature.

Factors explained.

  1. This is easy. Colder air temperatures cause the ground temperatures to go down also.
  2. I would say the air temperature in the summer for the heat pump was about 80 degrees. Now it is around 60 degrees.  This makes the heat pump work heard to get the tank back to the set point.
  3. The shower fixtures in my house have a anti-scald valve. This is for safety. This means that cold water is always mixed with incoming hot water and that comes out of the shower head. I use to have the tank set at 120 degrees. Now I have to have it set at 125 degrees to get the same hotness of water at the head. I was also informed today that “my shower was not hot enough”, so I may have to increase the tank temp. again.

If I had my old gas tank, I would only have to deal with 1 and 3. Personally, I think it is 1 and 3 that are causing the biggest increase in energy usage. This means I am still money ahead in using my hot water heat pump.

So I know, one of the best places to spend money is on improving the energy efficiency of your home. When I had the house built eight years ago, I was told the walls of the house were R-19. At the time, that sounded pretty good. Not that I plan on replacing my siding anytime soon, I just wanted to know what options I had to improve my R-value. Insulated Vinyl Siding is one such option. It costs about 30% more than regular vinyl siding. The benefit is greater impact resistance and the addition of R-4 to R-5 to the building walls. For me, this would be about a 20% increase insulation value. Since up to 40% of your home energy is lost thru your walls. 20% of 40% is 8%. This is why I would not be doing this until I needed to replace what I have. On the other hand, this “upgrade” does qualify for a federal tax credit of 30%. (for USA anyway) So now maybe a better time than I think.

What is 8% in my dollars? If I estimate $1500 for heating and cooling. 8% is $120. Not very much but we all know that utility bills will only go up. Since the regular and insulated siding cost about the same after tax credits. (No price quotes or concrete numbers, just the internet?) It would be a no brainer to install the better insulated product. Toolbase has a list of manufacturers if you are interested. They also have some helpful information.

It is a 25 Watt replacement. A15 bulb style. (normal bulbs are A19) This one is going into the freezer.

Here is a picture of a 40 Watt incandescent.

Original 40 Watt incandescent

Original 40 Watt incandescent

Here is a picture of the “25 Watt” LED replacement.

"25 Watt" replacement LED

"25 Watt" replacement LED

These are without flash and the same shutter speed. As you can see the LED is dimmer but it is also rated lower. The LED light is also directed out the front of the bulb. How does it look in the freezer? It looks just fine and the wife has not complained. Perfect!

I looked but I can not find one anywhere. So I made my own. I had an extra roll of R-13 insulation. I cut the roll into strips and taped the end together. Looks okay, but you have to remember this is in the utility room anyway.

Not Pretty, but not an issue.

Not Pretty, but not an issue.

I will have to watch the kill-a-watt and see if I get any better? Now with winter coming maybe my kw hrs won’t go up that much.

So I am visiting Florida. It is hot and Humid. My first question, do people even have heaters in there homes? I am sure they have electric resistive heaters. I would think they get used very seldom. The next question I had, why doesn’t everyone have a solar hot water heater. Just running the water thru the collector without any sun would at least get it up to ambient temperature. Which right now is 91 degrees. The next question is, why doesn’t everyone have solar modules on their roof? With the great solar insolation that Florida receives it would seem to be an easy option. It is easier to cool down from 90, then it is to heat from 20. Since it seems to rain almost every day, a rain barrel would have you covered on the days that you get missed by mother nature.

When it comes do to it, not much at all. Since I replaced my gas water heater, my gas usage has been about zero. Last month I used 2 CCF. This month I used 1 CCF. If I had an electric dryer that would have been an extra 58kW and 29kW respectively. So to have to pay almost $15 a month for gas, when all I would have payed extra for electricity was $0.60 seems  a bit ridiculous.

I am going to wait to replace my furnace/AC with a Heat Pump until next year. The outlook looks good for Natural Gas prices. If I can get one more year at of my old equipment with little chance a new heat pump would save me much money, the better. It would be nice to have a gas bill below $150 this year.

Cool your house with ice generated at night! That is right. Mostly right anyway.  Ice Energy has a produce that “makes” ice at night and uses the stored energy during the heat of the day. So for all you people out there that have TOU rate plans, this could save you money. (I am thinking of California!)

Basically, you have a regular AC unit that runs at night to make the ice inside the unit. When the thermostat calls for cold air, the ice is then melted providing the building with up to 30 ton-hours of cooling. (360,000 BTUs) I will use my house as an example. The other day it was 90 degrees outside. My air condition ran most of the day. Lets say 12 hours. I have a 2.5 ton unit. That would be about 2.5 x 12 hours = 30 ton hours. (convenient) If I was in California and had TOU (Time of Use) like most do, I may have paid $0.40 a kWhr. (3kW x 12hours x $0.40 = $14.40 a day) With the Ice Bear 30 that I run at night… (3.5kW x 10hours x $0.10 = $3.50 a night) That is a savings of $9 a day. A few things to note. One the regular AC unit is running in the heat of the day this will cause it to use more energy. On the flip side the Ice Bear is running in the cool of the night. This will cause it to use less energy. Even though the Ice Bear has a 4.3 ton compressor. It could use less energy because of the temperature difference between night ad day. In this example the AC would have never run out of ice until the end of the day. Everything is good. But if the ice did run out then the Ice Bear would have turned on it compressor and started to cool the building. Thus never leaving you without air conditioning.

On a similar train of thought. Think if you had a solar system installed. You would be selling power at peak rates and then buying it back during the cheapest times, middle of the night. This Ice Bear system could actually allow you to install a smaller solar system because of the rate differences. By the way, most power companies love it when you shift your load to an off peak time. Why? because they have excess capacity at night and not enough in the middle of the day. That is what TOU is all about. They want you to change how and when you use electricity. By making it cost more when they can’t generate enough.

Again, this technology is not for me. I have a flat rate structure. I also want a heat pump. This would mean I would have an Ice Bear and a heat pump and that would not make financial sense at all. It will work with heat pump. All they do is place a dedicated heat exchanger in the air handlers air stream. Everything works the same but you can run the heat pump in heating mode.

So, for some of you out there this can save you some serious money! Especially, if you already have solar on your roof.

If I have a backup style grid-tie solar system will my inverter start my Air Conditioner? Maybe, just depends on the Air Conditioners LRA rating and the inverter starting capacity. LRA means Locked Rotor Amperage. This is the inrush current that any motor  has when it first starts up. The motor in this case is the compressor.

Here is an example that may e similar to many installations. (This would be what I am thinking of doing in my house anyway.)

Inverter would be a Xantrex XW 6048. It has a LRA surge rating of 52.5 amps. My current air conditioner, I think, is a 2.5 ton AC unit. Since I don’t know the LRA rating I used a new Goodman SEER 13 unit. This unit has a LRA rating of 49 amps.

Yes, the inverter would start the Air Conditioner. Or would it. Remember there are two other fans in a split system. A condenser fan and a blower fan. Both of these have a LRA ratings also. So in the end the chance of starting the entire system is low. Especially since you will have other power users running while the Air Conditioner is trying to turn on.

So I can’t run the entire  house AC unit on the inverter. But can I run a small window unit. Yes, if the unit is 120V this inverter will not have a problem with it. That is because the inverter has a surge rating of 110 amps @ 120V. The house air conditioner was @ 240V.

If you wanted to run a window unit with an off the shelf inverter take the amperage while running and multiple by 7 to estimate the LRA draw. So if the running amps is 5. Then the estimated LRA would be 35 amps. Take the 35 amps x 120V = 4200 Watts. This would be the minimum size surge rating inverter you should buy.

Inverter-Driven Rotary Air Conditioners.

The nice thing about this type of air conditioner is the running amperage is very close to the Locked Rotor Amperage. The inverter in the AC unit starts the compressor out slowly and then ramps up to the desired speed. This means that if your windows unit or your central unit has this newer technology many more DC toAC  inverters will do the job. The Xantrex XW line of inverter should have no issues getting it done. (FWIW – when I upgrade my AC I would like to go with an inverter type heat pump.)