The First Energy Star House: 'Surprisingly Easy'

Once our construction company was launched on a path toward green building, we knew we had to convince our customers of the advantages of building green. But we quickly found out that our customers weren’t interested in doing anything that added any cost to their homes; so we decided to build our first Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. house on speculation.

We met with our third-party rater and were surprised to learn that we didn’t need to change any of our specifications to qualify for Energy Star. All we had to do was build a tighter-than-usual home by improving some of our insulating and air sealing details. For that to happen, we needed to pass the Thermal Bypass Checklist.

Since we were building a spec home, we wanted to keep costs down, so we built the house to our typical specifications. We didn’t include a closed crawl space or any other advanced option.

Choosing a ventilation system
Since we didn’t have much experience building tight homes, we were worried that the ventilation system might put the house under negative pressure. Where would the necessary make-up air come from? What type of ventilation system should we choose?

We met with our rater and HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. contractor and reviewed all of the options: an ERV(ERV). The part of a balanced ventilation system that captures water vapor and heat from one airstream to condition another. In cold climates, water vapor captured from the outgoing airstream by ERVs can humidify incoming air. In hot-humid climates, ERVs can help maintain (but not reduce) the interior relative humidity as outside air is conditioned by the ERV., passive fresh air inlets, central-fan-integrated supply ventilation systems, exhaust-only ventilationMechanical ventilation system in which one or more fans are used to exhaust air from a house and make-up air is supplied passively. Exhaust-only ventilation creates slight depressurization of the home; its impact on vented gas appliances should be considered. systems, and so on.

It seemed as if each solution came with at least one new problem. ERVs were expensive and would not necessarily provide make-up air when the dryer or kitchen exhaust hood was on. A passive intake would not condition the air and we would be bringing in very hot and humid air in the summer. The exhaust-only option relied on leaks in the structure to bring in fresh air. A central-fan-integrated supply ventilation system would not help with make-up air for the dryer or range hood, and would only work when the forced-air system was running. Unless we included a Fan Cycler control, the house wouldn’t get any fresh air at all during moderate weather.

For each option, we weighed cost versus value. We decided to connect an intake line to bring fresh outdoor air to the return side of our HVAC ductwork; the fresh air duct had a motorized damper that opened whenever the HVAC fan turned on. We felt with our hot/humid summers, it was important to temper the fresh air as we brought it into the building.

This proved to be a wonderful learning experience on our journey to green. I learned that sometimes there is no single correct or best answer; that every home is different; that we all have our own preferences; and that as long as you think everything through, it’s best to do whatever you feel most comfortable doing.

After all, the builder is the one that is going to have to provide the warranty on the home.

Surprise: leaky ducts
Our pre-drywall inspection went well; we passed on our first try. A little later, we discovered that our framer forgot to install blocking under the kneewalls — a problem missed by our rater. This was surprising, but it was probably a good lesson: we learned that we can’t just rely on our rater to find every problem for us.

We easily passed our blower-door testTest used to determine a home’s airtightness: a powerful fan is mounted in an exterior door opening and used to pressurize or depressurize the house. By measuring the force needed to maintain a certain pressure difference, a measure of the home’s airtightness can be determined. Operating the blower door also exaggerates air leakage and permits a weatherization contractor to find and seal those leakage areas.. Our first-floor ductwork also passed the Duct BlasterCalibrated air-flow measurement system developed to test the airtightness of forced-air duct systems. All outlets for the duct system, except for the one attached to the duct blaster, are sealed off and the system is either pressurized or depressurized; the work needed by the fan to maintain a given pressure difference provides a measure of duct leakage. test. We were thinking, “So far so good – this stuff is pretty easy.”

However, the second-floor duct system failed the Duct Blaster test. We were very surprised to hear this, as we had contracted with one of the better HVAC companies in town and we had never had any performance issues with any of their systems in any of our previous homes.

I started to wonder how many of our previous homes would have passed a Duct Blaster test. This was the turning point for me – we would never again build a house without performing a Duct Blaster test. What if one of our previous homes had a problem with the ductwork and we did not know about it? That wouldn’t be fair to the homeowner — after all, they paid for a properly performing HVAC system.

I really liked having a third-party verifier inspecting our homes. Because they could find something that we had overlooked, they could help us avoid costly warranty issues down the road.

Our duct problem was easily corrected, and we ended up with a HERS Index of 78.

Extra expenses were minimal
Back then, our building code mandated low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. windows and air conditioners with a minimum SEER(SEER) The efficiency of central air conditioners is rated by the Seasonal Energy Efficiency Ratio. The higher the SEER rating of a unit, the more energy efficient it is. The SEER rating is Btu of cooling output during a typical hot season divided by the total electric energy in watt-hours to run the unit. For residential air conditioners, the federal minimum is 13 SEER. For an Energy Star unit, 14 SEER. Manufacturers sell 18-20 SEER units, but they are expensive. of 13. For our Energy Star spec house, our only extra expenses were for certification, the ventilation system, backing up the knee walls with an exterior air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both., and extra air-sealing work.

We spent about $2,000 more than we typically would have on this home. After finishing the house, we made one of our first major green decisions: from now on, all of our homes would meet the Energy Star standard.

Danny Kelly is a co-owner of Kelly McArdle Construction in Charlotte, North Carolina.