Free Home Energy Audit And Investigation Report Case Study Example

Final Report

Part A. Energy Audit
Introduction
Initiatives to decrease energy consumption have largely focused on reducing domestic electricity. Using data from a domestic electricity bill can provide clear information about the high cost of one home’s electricity consumption. Furthermore, conducting an energy audit can help one discern which appliances are the most intensive. Analyzing the rooms and appliances that consume the most power will help direct plans to reduce electricity consumption. The following energy audit will provide the background data to help implement an energy reduction plan which will in turn have a positive impact economically by helping the individual save money on energy bills and also improve the environment by reducing carbon dioxide emissions.
1.1 Problem statement
Despite receiving energy bills on a consistent basis, often residents do not track their energy consumption nor do they fully understand their energy usage. There is also usually little understanding of how to read energy meters in their home or knowledge of which appliances consume the most power (Poel, van Cruchten, and Balaras, 2007). Depending on the age of their home, efficiency can be significantly altered due to poor insulation, outdated incandescent light bulbs, and other wasteful devices that could be improved.
1.2 Aims
This project was chosen to improve the sustainability of one user’s home and decrease their high energy bills. With this report, it is hoped that the user will have sufficient options to decrease their energy usage. The goal is to make quick, immediate changes to become more sustainable.
1.3 Objectives

Conduct home energy audit

Analyze the provided energy bill
Create Sankey diagrams
Include information about renewable energy system for the home
Conduct a cost assessment for reduction of energy bills
2. Energy Audit
An energy audit was conducted in the home to collect data on the energy consumption of rooms in the home and individual appliances using devices such as a Kill-A-Watt meter. Daily energy consumption was estimated based on approximate hours per day a device is used. Table 1 displays the energy audit data from the study.
2.1 Electricity usage
A broken down view of electricity usage per appliance, is noted in Figure 1. It is evident that the majority of the home’s electricity is partitioned for heating (both central heating and boiling water). It is interesting to note that lighting is a very small fraction of the energy costs of the home and therefore it might not be as important for reducing. This problem can easily be addressed by installing bulbs with a lower wattage or not replacing burnt bulbs with incandescent bulbs.
Figure 1. Home electricity usage
As shown above in Figure 1, the heating systems consume the most power at more than 50% of total energy usage. This is followed by the constant power draws of refrigeration in the kitchen, which accounts for nearly 20%. It is clear that to lower the home’s instantaneous power draw, the main area of power reduction will be to improve upon these two systems. Also not shown but worth noting are the instantaneous power draws of TVs & VCR at 3%, and Fans/Air Conditioning at 4%.
2.2 Heating inefficiencies
The furnace in the home is outdated. The current model was originally designed sometime in the 40s or 50s to burn coal. It has a 65% heating efficiency and used around 1,300 gallons of fuel in 2012. In the winter, the heating potential is mostly used for space heating--house heating-- and in the summer, it is mostly used to heat water for sanitation and cooking. Water heating during season is as significant as space heating in the winter.
In addition to the fuel cost, the furnace has a high maintenance cost per year.  Finally the furnace heats the basement and contributes to the basement overheating.
Figure 2. This visual conceptualization of the issues can help us see the interconnectedness and complexity of the system.
2.3 Sankey diagram
Sankey diagrams are useful for summarizing information from the energy audit and as shown in Figure 2, the Sankey diagram creates a visual for show electricity usage and estimated improved usage electricity and current price and estimated improved price.
Figure 3. Sankey diagram [insert]

Electricity usage: 1091.37

Estimated improvement: 702
Current price: £129.33
Estimated improved price £83.20
3. Conclusions

Part B. Solutions proposal

Strategies
As detailed earlier in this report, heating accounts for a high percentage of the home’s energy bills, and upon surveying the heating system it was quite obvious that there is a lot of room for improvement upon the system. During the winter, there is high demand on the central heater to warm the house as well as high demands for the hot water boiler throughout the year. There are a few alternative heating systems available. Namely, there is a possibility of replacing the two hot-air furnaces with a propane heater and installing a heat pump. Additionally, renewable energy solutions could be adopted as well as improving the insulation in the house and installing energy efficiency appliances.
1.1 General upgrades
Improved insulation, weatherproofing, and filling the heat escapes in the home would be a relatively low-cost and minimally disruptive action to take, which would save money and fuel. It is highly recommended to attend to these issues of heat loss regardless of whether or when a new heating system is installed (Gustavsson and Joelsson, 2010).
1.2 Alternative heating system options
This section gives an overview of some alternative heating options which would increase efficiency, save money and/or reduce the home’s energy consumption. There are a myriad of options available such as changing fuel types, installing new systems such as pellet burners, and natural gas that will be available depending on the scale (Eriksson, et al., 2007). Analyzing the current form of heating should be the primary determinant of which heating system to switch to. If the home is using furnaces for its central heating, it should consider replacing these with a propane heater that has 90+% efficiency. Propane contains 91,333 BTUs per gallon, according to the U.S. Energy Information Administration (EIA). Using the BTU values that the home consumes, the costs of switching to propane could be calculated. If the mathematics demonstrate that it is in fact not cost effective to switch to propane, then another alternative system should be considered.
1.3 Heat pumps
Another alternative heating system is a heat pump system. There are a few different types of heat pumps: air-source heat pumps, geothermal heat pumps, absorption heat pumps, and ductless mini-split heat pumps. The type of heat pump that best suits a building depends on several factors. The air-source heat pump does not work well in areas that frequently go below freezing, so this may not be the best option for the home. Absorption heat pumps only make sense for buildings that do not have an electrical source. Therefore, we recommend that a ductless mini-split heat pump and/or a geothermal heat pump are considered for the home.
According to the EPA, the ductless mini-split heat pump works well in colder temperatures. Because they are ductless, they also work well with propane heating systems or hot water heating systems, which could be useful to the home if it is decided to install a propane heater or install a solar hot water heater. It would also be useful for heating specific rooms and there are also models that can heat up to four different rooms. In addition, because they are ductless, there is less heat lost due to poorly insulated ducts.
A Geothermal heat pump uses the temperatures below ground, which are constant, to heat a building in the winter and cool it in the summer. This is advantageous because the consistency of the below ground temperatures as opposed to the above ground air temperatures allows it to reach efficiencies of 300-600%, compared to 175-250% of the common air-sourced heat pumps (Department of Energy, 2012). It works so reliably because no matter where you are in the world, a few feet below the ground the temperature stays the same thus in the winter, the ground is reliably warmer than the air and cooler in the summer. In addition, geothermal heat pumps are quieter, last longer, and require less maintenance than your typical air-sourced heat pump.
Although geothermal heat pumps have a higher cost than air-sourced heat pumps, they will last around 25 years (for the internal parts) and the ground loop would last for more than 50. According to the Department of Energy (2012), estimated payback time is 5-10 years. Figure 3 shows a diagram of a Geothermal Heat pump. This system requires excavation but has minimal energy use and could greatly reduce the home’s carbon footprint and heating bills
Figure 4. Demonstration of a closed loop system using a geothermal heat pump.
1.4 Bio-Sol Pellx Furnace
Pellet heating has the benefit of using renewable resources and has a lower carbon footprint than other fuel based heating solutions. Bio-Sol is a Swedish furnace which can work with pellets as well as oil, solar or electricity and/or combinations of these. Thus the separate coil systems within the furnace offer the possibility to combine solar and pellet energy quite efficiently. Another interesting detail is that there is a 6-9 kWh electrical resistance incorporated inside the furnace which can serve as short term back-up.
Heating with pellets cost approximately half the price it cost to heat with heating fuel. It costs around £9 in pellets against £17 in heating oil to generate on Mil. BTU’s (MMBTU).

Part C. iPhone investigation

1. Thermodynamic energy analysis

An analysis of the energy inputs, outputs, and losses was conducted for an iPhone which is shown in Figure 4.

Figure 4. Thermal image of charging iPhone
The thermal image shows small amounts of heat escaping from the iPhone but generally this is not a problem as Apple creates energy efficient devices (Apple, 2014). The following calculations describe the useful and wasteful energy dynamics:
Efficiency = Useful energy / Energy supplied + Waste energy
0.75 = Useful energy / 1125 J
0.75*1125 J = Useful energy
Useful energy = 843.75 J

Energy wasted by iPhone

= Energy supplied – useful energy
= (1125 J – 843.75 J)
= ~280 J
These calculates demonstrate that 25% of the iPhone’s energy is wasted as the device’s efficiency is 0.75. Simple algebraic mathematics were carried out to demonstrate this.

Overall Conclusions

Energy usage within a home is undoubtedly necessary; however, significant stride could be made to lower this home’s carbon footprint and save the residents money. The user should be much more informed about the energy consumption of each appliance in the home and can take the appropriate steps to lessen their energy consumption. The energy audit shows that the heating system is the most intensive draw of energy in the home and several improvements can be made from improving insulation to taking larger steps such as replacing the entire heating system with a more sustainable option. Overall, by taking the minimum actions outlined, the user can save ~$50 per month. Despite the fact that the pellet heating has a slightly shorter payback time than a propane heater (5 years over 4) and has a significantly lower yearly fuel cost, it has a higher cost in maintenance time and effort which might make a propane system more advantageous. Handling the pellets each month and emptying the ash collector every other week represent a major drawback. Propane in comparison has barely any maintenance needs. In addition, pellet system are not as reliable as other systems, and it is recommended (by most specialists we talked to) to have a back-up system.
Figure 7: Visual representation of some of the potential solutions. Again this map can help us see connections, complexity and think about the entire system at once.

Major Recommendations

Install basement ventilation: energy efficiency and health improvements start here
Reduced fan usage
Increased refrigerator compressor efficiency
Less radiant heat emitted to kitchen and dining area
Re-route piping from furnace to booster
Replace current inefficient furnace
1) Propane heater: payback time 7 years, easiest heating option for current situation
2) Wood pellet boiler: payback time 4 years, more sustainable but higher maintenance

Minor Recommendations

Consider removing the mini-fridge under the bar.
Consider replacing the current refrigerator with a more efficient refrigerator.
Unplug any electronics that are not in use to kill phantom loads, such as, power strips connected to TVs and VCRs, Air Conditioning units (mainly in the off-season). These are small savings that add up so do not feel terrible if you forget
Replace refrigerator seals, clear space and airflow around compressors in the basement, small things like this all add up to increase efficiency
Retrofit lighting with CFLs and L.E.D.s wherever possible. Incandescent bulbs use from 4-6 times as much energy as CFLs and L.E.D.s. Incandescents tend to produce warmer lighting and since affecting ambiance in the dining industry is a factor, consider changing out the incandescents in the basement. While basement lighting is much lower usage, it will not affect ambiance.

References

Eriksson, O. et al., 2007. Life cycle assessment of fuels for district heating: A comparison of waste incineration, biomass- and natural gas combustion. Energy Policy, 35(2), pp.1346–1362. [Accessed 20 February 2015].
Geothermal Heat Pumps, 2012. Department of Energy [online] Available at: http://energy.gov/energysaver/articles/geothermal-heat-pumps [Accessed 20 February 2015].
Gustavsson, L. & Joelsson, A., 2010. Life cycle primary energy analysis of residential buildings. Energy and Buildings, 42(2), pp.210–220. Available at: http://www.sciencedirect.com/science/article/pii/S0378778809002102 [Accessed 20 February 2015].
iPhone 6: Environmental Report, 2014. Apple. Available at: https://www.apple.com/environment/reports/docs/iPhone6_PER_Sept2014.pdf [Accessed 21 February 2015].
Poel, B., van Cruchten, G. & Balaras, C.A., 2007. Energy performance assessment of existing dwellings. Energy and Buildings, 39(4), pp.393–403. Available at: http://www.sciencedirect.com/science/article/pii/S037877880600212X [Accessed 21 February 2015].