By Amy Knight

Print Friendly, PDF & Email

The House We Live In: A Series on Building the Sustainable Home in Tucson, Arizona


The other day Matthew mentioned a problem that had been nagging at him (and bless him for letting there be such things as problems that are nagging him and not nagging me): venting the dryer. It’s inefficient.

He proposed a solution, a relative newcomer to the U.S. (kind of like the induction range; why is Europe so far ahead on these things?)—a condensing dryer, also known as a heat pump dryer. On the surface, that sounds good; If I’m passing up a gas stove to avoid the necessity of extra ventilation, shouldn’t I do that with a dryer, too?

He sent me this article about it. And my first reaction was strong resistance. We’ve already picked out appliances. Why are we doing this now? Isn’t this overkill? Do they really cost $1,800? Because… the conventional dryer we already picked out—a standard electric dryer—was already on the expensive side, at $800. The short answer, I learned with some googling, is yes, they really are that expensive.

So what is a condensing dryer? It works with a heat pump. Instead of blowing hot air on clothes and then venting it to the outside, along with some conditioned air I’ve already spent energy cooling, it has a heat exchanger, so the hot air goes through a loop where the water recondenses, and then it’s reheated and recirculated through the clothes, rather than just continually blowing inside air through and outside.

There are three potential ways this could help: by preventing unnecessary venting (thus preserving the good seal on the house, with the cool air staying cool), by eliminating the need to continually blow expensively conditioned air out while the dryer runs, and, potentially, by being more energy efficient to operate. The sources I’ve found conflict about whether they use significantly less power, or whether the energy savings are primarily in not causing the HVAC system to make up for the conditioned air you remove from the house to dry your clothes.

They are generally compact—not a problem for me, since I’m not trying to dry clothes for a big family, or a small family with messy kids. And they take longer. Of course, the one I’d already picked out is Energy Star-rated, and is among the most efficient of the conventional dryers. I’ve also learned that one can also buy a ventless dryer that works like a conventional dryer but collects the water in a reservoir you have to empty, for significantly less money, which would solve the seal problem but not reduce energy use much.

I haven’t made this decision yet—and I still have some time, although slightly less time than I might have with other appliances, because this decision makes a difference to the wall, not just what we plug into the eventual outlet. I don’t actually use the dryer all that often—especially in the summer, when things dry faster on a clothesline, and I tend to do laundry on the weekends, when I have time to hang things up during the day. Would energy savings be worth it? How big a deal is the venting? There are certainly more conversations to be had about this.

Either way, now, almost a year into the project, I’m still learning and learning and learning about things I’d never considered.

The house is in some ways a design experiment. It’s tempting to go all the way—if we don’t want a vent for a stove, we don’t want one for a dryer, either. But I’m also mindful of the fact that there is such a thing as overkill, a place where the energy savings are not worth the outlay, or the inconvenience that can come with owning something unusual. Anybody want to vote? 



Amy Knight is the fiction editor for In this weekly series, she chronicles the process of designing and building an eco-friendly house in Tucson, Arizona. The series will explore both how it’s done and what it means, from the perspective of someone who wants to do the right thing but knows almost nothing about sustainable building. Look for new posts every Monday. You can email Amy at or leave a comment here.

Image of clothesline courtesy Pixabay.

  1. Sure, I’ll vote! Not worth it. For one thing, I remember your recent post on total cost of ownership – how does that work out for a ventless dryer? Secondly, I question the energy loss through venting conditioned air. In my house the utility room (with washer & dryer) does not have an ac vent, and the nearest vent is some distance and corners away so I’m venting warm still air from that room anyway. Of course if you have an ac vent right by the dryer … but even then I find it hard to believe that the ac is working significantly harder, and much of that work is likely due to heat from the dryer rather than it sucking out cool air anyway. Finally I don’t like the idea of a sealed house anyway, which can lead to its own issues. Houses should breathe!

Comments are closed. is the world’s first online journal of place, publishing a rich mix of literature, artwork, case studies, and more since 1997.