Good news from Cleveland's first green home

Cleveland’s first green home was built two years ago and we now have some idea of how it works. It is mostly good and encouraging news, with one problem that needs to be worked on this summer. For a start, how about a $379 heat bill for the first winter (October-March , 2001-2002) and less than $100 more for this past very cold winter (2002-2003). And that includes hot water for cooking and bathing because the hot water tank also heats the house.

Good news from a green home

The GreenBuilt Homes, Ltd. Group that built this home set goals for each phase of the building process.

What has a year of occupancy taught us? GreenBuilt Homes hoped their house would heat for $300 the first winter (for six months). They missed their mark by $79, but are basically pleased as are the residents who had moved from a home that had heat bills for one month as large as the bills for this house for the whole winter. The house was monitored during a winter month to see how it performed temperature, humidity and CO2 wise.

A side entry hallway with a door that closed to the interior was the primary entry used and the residents were careful to keep the interior door shut until the outside door was closed. Temperatures remained stable throughout the test period. The humidity also stayed stable. Carbon dioxide which is released when we breathe and when we cook, experienced some severe rises at several points but we were quickly able to figure out what was happening and correct the problems.

The residents had been careful to use the range hood (which is vented directly to the exterior) whenever cooking on their gas range. But on one occasion they used the oven to do a roast and discovered the CO2 levels had climbed rather high. They had forgotten that a gas range emits all the by-products of its oven combustion into the living space which includes lots of CO2. They have learned to turn on the fan when the oven is being used, and this has kept the CO2 levels normal when cooking.

But the CO2 also rose when a large group of persons were visiting. A lot of people breathing can significantly increase CO2 levels. After experimenting with the use of one or more bath fans when many persons were visiting, the residents discovered that turning on the second floor bath fan for the duration of these visits kept the CO2 levels under control. A very minimal price to pay for better indoor air quality.

Speaking of indoor air quality, a friend of the residents, a person with severe asthma, visited for a day and found the living space the most comfortable she had been in for some time.

The residents adopted a “shoes off at the door” policy for themselves and those who come to visit and they feel this has helped reduce indoor air issues as well as the GreenBuilt effort to reduce the number of building products that could outgas and cause distress to residents and their guests.

The one disappointing experience of the first year of occupancy was the air conditioning cost. It turned out to be slightly higher for the six months of April through September than the cost of heating. The air conditioning was kept on continually, but at a reasonable temperature. We will be keeping a close eye on this over the summer.

One theory is the heat generated by the sun entering a window high on the front wall of the house which faces west. In Cleveland, we see very little of the sun in the winter, but we see a lot in the summer. The late afternoon sun enters that window and remains there for several hours significantly warming the area adjacent to the hallway where the thermostat is located. The residents will try to shade that window this summer to see if that will help reduce the cooling demand. We will also be monitoring the air handler more closely to see if any hot water is making its way into the heating coil there. If so, it would mean the air conditioner is working over time trying to cool. We’ll report on what we have learned.