http://fireflyeco.com/
rss
email
twitter
  • About

Everything I needed to know about home energy I learned from a beach ball.

4 comments
Posted on Oct 8 2010 by Daniel
Tweet

credit: colemama

True or False?

  • Cranking the thermostat up ten degrees makes the house heat faster than turning it up two degrees.
  • You waste as much energy re-heating the house with a programmable thermostat as you do just keeping it warm all day.
  • Most of the energy wasted on re-heating a cool house goes into warming the walls and surfaces.

Answer:

False. False. False. False. False. (Two extra falses to prove the falseness of all of these falsities.)

I hear arguments like these from lots of people, even energy managers and HVAC people, and I just don’t know where the information came from.

Tom Harrison, over at Five Percent, unpacks these myths and gives you the breakdown on how you should REALLY think of your thermostat and home heating system.  He uses a great analogy of a leaky beach ball to demonstrate why programmable thermostats can actually save you energy:

Heating your house is like pumping up a leaky beach ball.

At first, it’s easy.  As the ball gets fuller, the air leaks out faster, so it’s harder to get to “full”. Once it’s full, you still have to keep pumping it up since air leaks out. If you stop pumping the air still leaks out — quickly at first, and more slowly as the ball gets flatter.

So in this silly analogy, a full beach ball is a warm house. Pumping uses energy, like the furnace. The leak represents the way your walls actually work, some are better or worse at slowing down the rate of heat loss, but they all leak.

It makes sense, then, that letting the house cool down means the heat leaks out more slowly, and the total amount of energy it consumes over the course of a day is less than if you kept it warm 24/7.  A house with a programmable thermostat is a beach ball where the pump is on a timer, and the ball is only full when you’re ready to play.

I like it!  And it’s good information as we enter the heating season.  Just be careful about which thermostat you buy if you have a heat pump… it could cost you big.

Can't get enough? Try these related posts:

  1. How to Calculate Energy Savings in a Building
  2. Beware the Heat Pump Thermostat
  3. Home Energy Upgrades: What Should I Do Next?
  4. Tools of the (Energy Nerd) Trade
  5. Man vs. Machine

  Tags: efficiency, home comfort, HVAC, thermostat Category: Energy, Residential
  • http://fivepercent.us/ Tom Harrison

    Great post, Daniel! I love the topic, and thanks for the quote :-)

    I looked and looked for a deflated beach ball for my post — I like yours better.

    Also, a plug for my company — check out Energy Circle for some really solid content on all of the topics you’re covering.

    Rock on!

    Tom Harrson

  • http://www.forthgo.com/blog/ Xan Gregg

    The linked article would be more convincing for me with some real math and graphs. I imagine inside temperature over time is a sawtooth function, but at lower temps the rises (the parts you pay for) are shorter and the falls are longer.

  • Jim

    I’ll try this beach ball analogy on my next customer. They almost all ask if occupancy schedules really save any energy. Using my standard heat loss is directly proportional to the inside versus outside temperature difference explanation tends to deflate their interest.

  • Pingback: PlotWatt Labs: Boiling a pot of water, Part II | Firefly Ecometrics - Light for the path to sustainability.

Twitter

What you’re saying:

  • Joeblow on Solar Sheep
  • lu9 on Homestar. Sewiously.
  • Leslie Davis on BizBuzz: Plastic Bags into Oil

Blogroll

  • information aesthetics
    Hans Rosling's Shortest Talk Ever
    May 21, 2012

  • mapawatt
    Find Energy Incentives
    May 21, 2012

  • FlowingData
    The U.K. energy consumption guide
    May 21, 2012

  • Green Building Advisor Blogs
    Staying Cool with a Metal Roof
    May 21, 2012

  • Visual Business Intelligence
    Data Art vs. Data Visualization: Why Does a Distinction Matter?
    May 18, 2012

  • Chart Porn
    Compendium of Advanced Graphics Tools
    May 18, 2012

  • Energy Circle
    ReCircle: Financing Home Solar, Zero-VOC Paint, a Bathroom LED Upgrade, and more!
    May 18, 2012

  • JMP Blog
    10 tips for making analytics converts out of your colleagues
    May 17, 2012

  • Gemba Panta Rei
    Where is Your Suggestion Box?
    May 16, 2012

  • Lean Insider
    Problem Solving and the Lean Journey
    May 7, 2012

Categories

  • Carbon
  • Commercial
  • Design
  • EcoMetrics
  • Energy
  • Financial
  • Food and Agriculture
  • InfoVis
  • Lean
  • Nature
  • PlotWatt
  • Policy
  • Pollution
  • Presentation
  • Residential
  • Solid Waste
  • Transportation
  • Water

Tags

agriculture appliances bacteria biomimicry buildings cap and trade carbon footprint cash for clunkers CFL climate change computers corn data efficiency electricity grid home comfort humidity humor HVAC LCA Lean LED legislation lighting maps marketing offsets oil organic recycling renewables SciLights smart grid social justice software solar statistics subsidies TEDTalks transportation UNC visualization waste Water

  • About
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License