What happens during a typical energy audit?
After arriving onsite, the auditor talks with the client about the home, and the client’s experience in the home. The auditor and client tour the home, and the client is able to point out any areas of concern. The auditor measures the footprint and interior spaces of the home, and draws a physical map of the home. The auditor takes photos and notes of any energy-related features in the home. If there are appliances that Read more »
How much does it cost to raise your home’s temperature?
A client recently asked me how much it costs to raise her home's temp during the day. This is a simple way you can get that same info (this is a different cost from maintaining that temp): For gas heating systems: Get a stable home temp (turn the thermostat to 65F and let it alone for about an hour).Turn to "pilot" or "off" all of your gas appliances except the furnace (water heater, dryer, Read more »
Heat Pumps Explained
Heat pumps deliver more heat to your home than they consume. How? The magic is in the ability of refrigerants to absorb heat when they expand, and release it when they compress. The refrigerant is compressed inside a home, releasing heat, then moved through pipes and allowed to expand in copper tubes outside, absorbing heat. Essentially the heat pump is simply moving the heat from outside to inside. Most of the energy used is in the compressor to make Read more »
Is it cheaper to heat with gas or electricity?
Given the same mechanism for heat transfer (blowing air over a heating element, for example) gas and electricity use the same amount of energy to heat the same volume of air. Energy is measured in many different units, but generally British Thermal Units (BTUs) for gas and kilowatt hours (KWh) for electricity. At my house in Bellingham, I spend about 13 cents per Kwh and about $1.10 per 100,000 BTUs, or one therm. I take Read more »
Solving the $1000 Per Month Heating Bill
A client recently told me that during the depths of last winter, he was spending upwards of $1000 per month on propane. My first thoughts were that the house was too leaky, or not insulated, or that the ductwork was shot. But, through diagnostic testing, I realized that the real problem lay in the appliances he was using to heat his home. One propane water heater tank heated the radiant floor in the basement, a Read more »
My house is insulated, but I’m still cold.
My attic is insulated with fiberglass batts. Thank you, insulation contractor! Wait, what happens when I look under this batt of insulation? Oh, I have no effective insulation. I want my money back! Lesson to insulation contractors: Align the pressure and thermal boundary. In english, this means make sure that the insulation touches the air barrier (usually the surface that you touch from the inside of the house).
Carbon Monoxide deaths
Carbon monoxide (CO) is an odorless, colorless, tasteless gas emitted by the incomplete combustion of fuel. It comes from wood, natural gas, charcoal, and almost everything else that burns. CO binds to hemoglobin and prevents oxygen from entering or leaving the bloodstream. This means that oxygen that it carries can't be transferred to the brain, heart, muscles, or any other organ that needs it. Symptoms very widely, but commonly include headache, nausea, flue like symptoms, Read more »
Would you replace this window?
Every building material resists heat flow in some manner. Glass does it poorly, fluffed insulation does it really well. The ability of a material to resist heat flow is called its R-value. When I recommend ugrades, such as adding insulation to the attic, I use software that generates a payback time for the upgrade, taking into account the R-value and cost of installation. It may cost a thousand dollars to insulate an attic, but Read more »
Oh, rats!
My friend with the whiskers would like to say "Hi!" He is a prime example of misaligning the pressure and thermal boundary. In any heated space, the boundary that holds the warm air inside of your home (pressure boundary) should be touching, and on the warm side of, your insulation (thermal boundary). In this case, the insulators put 6 inches of insulation in a 10 inch joist bay in a crawl space, and fastened it Read more »
CFM50 hit the BTL which raised the CAZ
Jargon. I forget how much of it I use until I get that blank stare from a client. So here is a primer, and a reminder that if I start using too many acronyms in a conversation, you are to poke me in the chest and say "Hey! Speak English!" CFM50: Cubic feet per minute at 50 pascals. The standard way of finding out if a house is leaky or airtight is to depressurize the Read more »