Slide outline for Lesson 4.4. Day 1 has twelve slides; Day 2 has nine. [Sal: slide 5 is yours. Put one photo from your Penn State zero-energy home project on it and tell the story in two minutes.]
Day 1
Where does it go?
- Lesson 4.4, Day 1
- Today: where a home's energy and water go, and the math that shows what a fix is worth
- Tomorrow: you audit this room
Teacher notes
Image: a house drawn in cross-section with arrows leaving through the roof, the windows, the faucet, and the outlets.
Do now
- Name three things in your home using electricity right now while nobody is using them
- Guess: what does one light bulb cost to run for a year?
- Two minutes
Teacher notes
Write the three-things list on the board and circle the phantom loads. Hold up the two bulbs for the hook.
Energy in a home
- Heating and cooling: about half
- Heating water: about a fifth
- Everything else: lights, fridge, laundry, electronics, cooking
Teacher notes
Image: a pie chart with a furnace icon on the biggest slice, a water heater on the next, and a bulb, a fridge, and a TV on the rest.
Rounded from U.S. EIA residential data. Students fill Part 1.
Water in a home
- Toilets: about a quarter
- Showers: a fifth
- Faucets: a fifth
- Laundry: a sixth
- Leaks: about a tenth. A tenth of the water bill goes down a drip.
Teacher notes
Image: a pie chart with a toilet, a showerhead, a faucet, a washer, and a drip icon.
Rounded from EPA WaterSense.
A zero-energy home
- [Sal: your Penn State project. One photo, three lines: what it is, what it cost, what surprised you.]
Teacher notes
Image: [Sal: your photo or drawing.]
Two minutes. This is the story students will remember from this lesson.
Phantom load
- A device that draws power while "off": chargers, TVs, cable boxes, game consoles, microwaves with clocks
- About 5 to 10 percent of a home's electricity
- Watch the meter
Teacher notes
Image: a plug-in electricity meter with a game console plugged in, reading 14 W.
If you have the meter, plug in the biggest phantom you tested. If not, the number on the slide stands.
Two words
- Conservation: using less of a resource on purpose so it lasts (the state's definition in plain words)
- Efficiency: getting the same result with less
- Turning off the light is conservation. The LED is efficiency. You want both.
Teacher notes
CTE SUS 3. d) is "define conservation as it applies to energy." Students write both definitions.
The math, one bulb
- 60 W x 5 hours x 365 days = 109,500 Wh
- Divide by 1,000 = 109.5 kWh
- x $0.25 = $27.38 a year
- The LED: 9 W. 16,425 Wh = 16.4 kWh = $4.11
- Savings: $23.27 per bulb. Twenty bulbs: about $465.
Teacher notes
Image: the two bulbs side by side with the wattage circled on each.
Work it on the board with the template. "Watt-hours are pennies, kilowatt-hours are dollars."
The math, a drip and a thermostat
- One drip per second is about 5 gallons a day
- 5 x 365 = 1,825 gallons a year, about 30 bathtubs
- Thermostat: each degree set back for 8 hours saves about 1 percent of the heating bill
- 7 degrees at night saves about 7 percent. The fix is a sweater.
Teacher notes
Image: a faucet with one drop falling, and a thermostat dial turned to 65.
Pairs do the three practice problems on the handout, Part 2. Check with the pair beside them.
The audit checklist
- Lights: on in empty rooms? LED?
- Phantom: chargers, screens, consoles
- Heat: thermostat, open windows, blocked vents, drafts
- Water: drips, a running toilet, shower length
- Appliances: fridge seal, full loads, cold laundry
- Score each line: OK, Fix (free), Fix ($)
Teacher notes
Walk the twelve lines in Part 3.
Practice on a bedroom
- A lamp on with nobody in the room, old bulb
- A laptop charger plugged in, no laptop
- A space heater running with the window open two inches
- A radiator with a dresser in front of it
Teacher notes
Image: a bedroom photo with those four things visible.
Score it as a class, one line at a time. Every line here is a free fix except the bulb.
Exit card
- 3 places a home's energy goes
- 2 phantom loads you will unplug tonight
- 1 number from today's math you will remember
Day 2
Teacher notes
Assign five teams and five zones of the room for tomorrow before they leave.
Audit day
- Lesson 4.4, Day 2
- This room is the client
- Five zones, one team each, ten minutes
Teacher notes
Image: the classroom with five zones outlined.
Do now
- One bulb: 60 watts, 5 hours a day, 365 days
- How many watt-hours?
- Divide by 1,000: how many kilowatt-hours?
- Two minutes
Teacher notes
109,500 Wh; 109.5 kWh. Leave it on the board.
Audit the room
- Take the checklist and a clipboard to your zone
- Score all twelve lines
- Every fix: free or money
- I planted something in every zone. Find it.
Teacher notes
Circulate. Reveal the planted wastes at ten minutes.
Audit the apartment
- The Marchetti-Oyelaran apartment, Part 4
- Two adults, one child, a rental; the landlord pays for heat, the family pays for electricity and hot water
- Read it room by room; score the same twelve lines
- Ten minutes
Teacher notes
Watch for the heat lines. The family does not pay for heat, which changes who should fix what.
Twelve fixes
- Each has a cost and an estimated yearly saving
- Cross out the two that cost more than $50
- Rank the other ten by savings, highest first
- Payback = cost / savings per year
Teacher notes
Image: the twelve-fix table from the handout.
Common mistake is ranking by cost. Say it twice: cheapest first is the filter; savings is the rank.
Who pays?
- The landlord pays for heat. Who should buy the weatherstripping?
- The family pays for hot water. Who should buy the low-flow showerhead?
- The fridge seal is torn. Whose fridge is it?
Teacher notes
Take three answers. This comes back in the Design a Room budget.
Read the bill
- Electricity used: 650 kWh
- Supply $0.12 per kWh; delivery $0.13 per kWh; together $0.25
- Basic service charge $18: the same every month, even at zero
- Total $180.50
- Ten LEDs save about $230 a year: next month's bill drops about $19
Teacher notes
Image: the sample bill from the handout with the five numbers boxed.
Exit card
- Your top three fixes
- One sentence: why the first one is first
Teacher notes
The quiz in Lesson 4.5 has one energy math item and one water math item with the numbers given.
Reset the room
- Turn off what we turned on to find it
- Chargers unplugged, windows closed
- This room is now audited. Keep it that way.