Your home: calculating potential energy savings with a home heating index
Miles-Per-Gallon
This is about taking the miles per gallon approach to calculating the performance of domestic heating and potential energy savings at home. I will talk about the formula of the index of domestic heating, which will allow you to assess your energy performance and energy-saving potential. Using this formula, you will have an idea of how much energy you can save and how cost-effective these energy saving measures are.
I compare this to the miles per gallon of the vehicle. Raise your hand if you carry a small calculator in your car to find out miles per gallon. The calculator I use is one of the first solar-powered calculators to enter the market. There is no backup battery, if I'm going to figure out how many miles per gallon my car got on the last tank of gas, I need to wait and fill the daylight.
Along with assessing the energy efficiency of your trips, I also believe that most people are interested in evaluating the energy efficiency of their homes. Is your home a 1-ton, four-wheel drive, pick-up truck with oversized tires, or is the three of you who came to America on a boat? Of course, the performance of the house is different from the performance of cars in one very important way; your house cannot be seen from the parking lot, trying to impress the girls.
The house should look good, but when it comes to performance, the less energy is used better. I heard that people replace their car engine with a larger, more powerful model, and then brag about all the fuel it consumes, but I did not hear anyone leave the doors and windows open in their house, and then boast about their high electric bill
Like mpg in a car, fuel consumption in homes can be measured, so you can judge the benefits of installing energy efficient measures. When we talk about the house, instead of using miles per gallon, let us use something that the housing industry uses, let me call it the home heating index. The heating index is a means of comparing homes of different sizes and climatic conditions and determining the economic efficiency of energy saving measures.
Home energy use
In heating climatic conditions, where the days of the heating period (often used in a furnace), the number of days of cooling (often used air conditioning), the calculation is called the index of home heating. And then, similarly, when the days of the degree of cooling exceed the number of days of the degree of heating, this is called the home cooling index.
Today I am going to demonstrate only the index of domestic heating. The heat index turned out to be more useful and accurate than the cooling index. In addition, outside and time is cold to worry about heating. (Except for you, people in the far south, I will talk about the Home Cooling Index another time.)
Thus, before embarking on an adventure climbing to the attic, studying the underfloor, exploring the efficiency of the appliance and all the other things that occur during an energy audit, you have to pull out your favorite solar calculator and calculate the home heating index. With a home heating index, you can usually correctly guess if there is insulation in the attic or not, and when there is, when you need to add more.
Calculation of the index of domestic heating:
The household heating index is a calculation using Btu, square feet of living space and heating days. This calculation can be performed wherever the house heating system is electricity, gas, propane, wood, oil or candles.
The home heating index for a house with heated wood is a little more involved, because Btu is designed for a cord for one look. I think I will leave the forest burning for a while after I receive the new calculator.
Let us calculate the index of the internal heating for an electrically heated house. This will include an electric furnace, space and wall heaters, heat pump, warm heat flow or heat for the floor, etc. For this calculation, we assume that there is an electric water heater in this house.
Step 1: Electric Account Data
Power Consumption Bill Power Consumption
Take an electric bill and look at the number of kilowatt-hours that your house used during October. In my example at home, the house used 1640 kWh per month. Now look at the histogram and select the month when electrical usage was the smallest. This is the month when your heating and cooling needs were the least, estimate the kilowatt-hours used during this month. In my example, at home, in the month of September, about 680 kilowatt-hours were used. This figure represents the electricity used for water heating, cooking, lighting, etc. - everything except heating and air conditioning.
Subtract 680 from 1640 - the difference is 960 kWh. This is the energy used for heating during October.
Step 2. Find the number of heated square feet in your home.
My example of a house is a two-story house. On the second floor - 920 square meters. Feet, and on the second floor - 800 square meters. Total area of feet = 1,720.
You may have to pull out an old measuring tape, remember, square feet of length times the width.
Measure your home
Step 3: Determine the heating time for your location during October.
Go to http://www.degreedays.net.
In the field labeled "Weather Station ID" enter your zip code and click "Search Station". The box will fall down, select the meteorological station nearest to your home.
For Degree Day type, select “Heating”, and for temperature units, select “Celsius” or “Fahrenheit”.
Leave the base temperature at 65 degrees and select the checkbox to enable “Base temperatures nearby.”
To select "Select", select "Monthly" and "Period covered by the period", select "Last twelve months".
Now you are ready to click on “Generate Degree Days”.
At the top of the screen, a new box with a circular circular wheel will appear, which reflects the graded heating days. Wait until the wheel stops and “Days of your availability” appears in the box, and then click “Download Now”.
Open the downloaded chart and select the number of training days for October. For my sample home, the graduation days are 344.
Step 4: Convert kilowatt-hours to Btu.
The equation uses Btu, so we need to convert kWh to Btu. The following diagram will allow us to do the conversion. If you are working with natural gas or propane, these conversion numbers are also indicated.
1. One kilowatt-hour of electricity is equal to 3.412 BTU.
2. One heat stream of natural gas equals 100,000 BTU
3. One gallon of propane is equal to approximately 91,450 BTU.
In my example, the house used 960 kWh hours for heating, which is converted to: 960 times 3,412 equivalents 3,275,520 BTUs.
Step 5: Insert the data into the internal heating index equation.
Length x width
To use the data we collected to determine the index of internal heating, the first thing we want to do is multiply square feet by the days of the degree of heating. Again, for my sample house, I would multiply 1,720 square feet by 344 degrees of heat days. Multiplied together equal 591 680.
Now we need to divide Btu by 591,680. This will be 3,275,520 BTUs, divided by 591,680, to provide an index of internal heating of 5.53. To estimate the internal heating index of 5.53, we use the following table for houses with fossil-fired heating and slightly change the schedule for electric-heated houses.
Home heating index from 0 to 2; Tightness, superinsulation, heating efficiency over 90+, heat recovery fan, small window area and high r value.
Between 2 and 4; Well insulated, low air leakage, efficient heating system, home labeling of super good cents in the USA or R-2000 in Canada.
Between 4 and 8; Better than an average house with good insulation. Relative low air leakage and higher than average heating efficiency.
Between 8 and 13; Medium house with medium insulation, medium air leakage and average heating efficiency.
Between 13 and 18; Worse than average home, with little insulation, high air leakage and worse average heating efficiency.
Between 18 and 22+; Old houses with poor insulation, abundant air leakage and a very inefficient heating system.
(Chart index of domestic heating from residential energy by John Kriegger)
Using the diagram, we can see that my example of a home with a 5.53 home heating index is not a high performance home, not an energy swamp. This is a better than average home that can benefit from additional insulation, additional air sealing and can benefit from a higher efficiency of the heating system. We can also look for additional energy savings through more efficient appliances and efficient lighting.
Using the Home Energy Index, we can see that some additional modifications to increase the weather can reduce energy consumption and be cost effective. If the house had 1.5 points, it would probably be impractical to carry out a modernization of weathering. However, if the house had 15 points, the house could greatly benefit from energy saving measures, both for devices with a higher degree of weather conditions, and to increase efficiency, and these modifications would certainly be cost-effective.
Unfortunately, the home heating index is a little more difficult to calculate than the vehicle miles per gallon. However, the consequences are even more important. Most likely, you can’t do much to increase your favorite car’s miles per gallon, but the same doesn’t apply to your home, the chances are very good that you can increase the energy efficiency of homes and save a lot of money so you can use to buy gas car.
Thank you for stopping, I hope to see you soon, but I will not leave a light for you ...
