Some HVAC contractors might feel a little pressure being called upon to design and install a comfort system in the newly constructed home of a certified home energy rater. That wasn't the case for Eric Kjelshus, owner of Eric Kjelshus Energy, Greenwood, MO. In fact, one the reasons home-owner Amy Walker selected her long-time friend Kjelshus for the job is because he had proven his knowledge of superior HVAC design by teaching classes for Walker and other energy raters in the Kansas City area.

"As a home energy rater, I designed this house myself to be very energy efficient, and I wanted a well-designed high performance heating and cooling system. I knew Eric was the contractor to do that," says Walker, who in addition to being a home energy rater is also certified by the U.S. Green Building Council (USGBC) as a LEED AP for Homes under the USGBC's Leadership in Energy and Environmental Design (LEED) program.

"Eric definitely does not believe in just putting a system in as quickly as possible and then walking away from it," Walker adds. "He did a lot of testing and commissioning, which is not something many other contractors do. He tested airflow, balanced the system, and performed radon testing both before and after I had a sump pump lid put on. He was concerned not only about the performance of the system but also the indoor air quality of the home."

At Home Along the Oregon Trail
Walker's home sits on the north branch of the Oregon Trail, which in the mid-1800s was the only practical corridor across the Rocky Mountains to the western United States. Washington, Oregon, California, Nevada, Idaho, and Utah would probably not be a part of the U.S. today, were it not for the Oregon Trail.

The first emigrants to take the Oregon Trail from Missouri to Oregon in a covered wagon made the trip in 1836. In 1843, a wagon train filled with about a thousand pioneers dubbed "the great migration" kicked off a massive move west on the trail. Over the next 25 years, more than a half million people took to the trail. Actual wagon ruts from the Oregon Trail still exist today in many parts of the American West.

While the HVAC system in Walker's home is relatively simple and straightforward, it would only have been a dream of those early settlers, and the home itself is a masterpiece of modern green construction. According to Kjelshus, the home is built to meet or exceed the green building standards of the National Home Builder's Association, the Environmental Protection Agency's Energy Star and Healthy Home programs, LEED for Homes, the Air Conditioning Contractors of America (ACCA), the National Comfort Institute (NCI), the Building Performance Institute, and the National Association of the Remodeling Industry.

Although the home sits near a major highway, it’s so tightly constructed that not even the drone of traffic gets in. It includes 1.5-in. of foam on 2 x 6 exterior walls filled with blown-in cellulose. The attic is R-50 cellulose with foamed top-plates. The basement has a 2-in. foam board interior.

All appliances in the home are Energy Star qualified. Paints and stains used are low volatile organic compound (VOC).

Daylighting was used to increase light while decreasing the electrical load in the bathrooms. The home's south-facing glass incorporates a passive solar system designed by Walker to capture the 1,000 Btus per sq.ft. of heat they receive in the winter, and store it in the slab floor. Energy Star windows with argon for shading in summer were installed, and the attic and walls were all sealed before and after sheet rocking. All exhaust vents from the kitchen and bathrooms are dampened twice for extremely quiet operation.

All ducts are sized per ACCA Manual D, and heating and cooling loads were calculated using ACCA Manual J8. According to Kjelshus, the air conditioning unit for the home is actually slightly oversized, so he installed a two-stage unit with a variable speed fan to ensure optimal comfort and humidity control.

"With the windows closed the system can drop the relative humidity in this home by 10% in one hour," Kjelshus says. The annual heating and cooling costs are estimated to be only about $600, plus another $200 to run both the ERV and the variable speed motor. The two-stage condensing unit handles the cooling needs on low stage until the outdoor temperature reaches almost 100 degrees, drawing only 4.6 amps in the process.

Remarkable Tightness
Perhaps the most remarkable feature of this home is its tightness, and for that, Kjelshus tips his cap to Redstone Homes, and owner Jim Kostusik, in Overland Park, KS. "I was hooking up a dryer vent when someone slammed the front door, and the pressure change knocked the vent right out of my hands," Kjelshus says. "I thought that was pretty interesting, but topped it one day when I shut the back door while the carpenter was adjusting the hasps on the front door. He yelled at me for knocking him over, from 60 feet away."

Kjelshus and his team used American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) Standard 62.2 for venting this exceptionally tight house. During the company's thorough commissioning, the house tested at 1.2 Pascals positive pressure with the energy recovery ventilator on, and 1 Pascal negative with it off. Duct leakage measures less than one percent.