Mary James spoke recently with Sarah Evans, owner of a Passive House that was completed last May in Salem, Oregon. The home is profiled in Recreating the American Home: The Passive House Approach.
How has the experience of living in your new Passive House been? Any surprises?
We had to learn how to use our PH so that we didn’t have to blast the air conditioning. It doesn’t get super hot in Salem, but there were probably three times during the summer when it reached 100° for a couple of days. The first time we didn’t close our blinds, and we did a bunch of laundry on a really hot day. It got really hot inside, and we had to turn on our air conditioning. (We have a ductless heat pump for heating and cooling.) We realized maybe we shouldn’t do all those heat-generating activities when it is really hot. The next time [a heat wave hit] we were better prepared. We closed all our curtains and blinds to cut off the solar gain during the day. At night we opened all our windows to let in cooler air and turned off the heat recovery portion of our energy recovery ventilator (ERV) at night. So instead of recovering heat from our inside air before sending it to the outside, we let it ventilate out and let the cooler outside air ventilate in, without any heat exchange. Then we would close everything back up in the morning and turn the heat recovery back on. Once we learned to do all that, we didn’t need to turn on our air conditioning. And that was pretty easy to do.
This whole summer we only used the air conditioning three times, and each time was only for an hour or so. Once was the first heat wave; the second time was when we had an open house, and it was a hot day; the third time was when we had a bunch of friends over.
Normally you leave the ventilation system running all the time?
Yes, we have the ventilation system automatically running all the time. When we wanted more cool air to come in at night, we opened the windows and turned off the ventilation. It doesn’t get very humid in Oregon, so we haven’t had any humidity issues.
Were there any other surprises?
That was the main one. We learned about how much heat we generate ourselves by doing laundry, cooking dinner, and having friends over. We knew that [theoretically], but we were surprised seeing it in action. When the fall arrived, it was nice during the day, but the temperature would drop down into the 30s at night. The house hovered between 71° and 74°, even though we hadn’t turned on the heat at all, just by generating the heat ourselves.
Is there anything you wish you had done differently, or any costs you could have cut?
No not really. Nothing was overkill. Our builder was very conscious of our budget. I wouldn’t change anything.
How have your utility bills compared to the bills at your old house?
That is hard to say until we get through a winter. Through the fall, we’ve been averaging about 14 KWh of energy use per day. We’ve been tracking our energy usage online using the energy detective (TED). I think it’s really cool. It naturally makes you think a little more about your use. You become more aware of the times of day when you use energy and how. I like that.
Another factor affecting our energy bills is now we have a solar water heater, which has really helped us a lot—and that’s not a Passive House element. Over the summer we didn’t have to use the electric backup at all.
Check out Sarah Evans and Stuart Rue’s blog at blog.stuartrue.com for more details on how they fared through the winter. As they say there:
During a one-year period we spent $1,620.76 on energy (electricity + gas) at the old house. We are on track to save about $950 per year in our Passive House. And all of this while being more comfortable than we ever were in the old house. No more cold drafts, no more chilly corners, no more icy floors.
