Thursday, February 24, 2011

Recapture Your Dryer Heat

One of the more interesting aspects of running this blog is that I wind up photographing my laundry room perhaps more than is healthy.  But today, I want to show you a project that has worked extremely well for us:  our mechanism for venting the dryer inside the house to recapture all of that heat.

We actually have been using this system for about a year; I have held off writing about it until I could test it in all seasons, because one of the traditional problems with venting a dryer inside is build-up of humidity and, therefore, mold.  But in our situation, we have that well under control, and I think many of my readers could do likewise.

What you see above is a baffled vent box.  It is just a plastic box that you put in your dryer vent tube; it has a flippable baffle inside so you can close it and send the air outside or open it and direct the air into the house.  It also has a removeable vent screen to catch any lint.

By itself, this is a good idea.  You can vent to the outside in the summer and to the inside in the winter.  However, if your dryer is in an enclosed space, as mine is, the humidity will quickly build up on the walls, removing the wallpaper at the very least.  So, Mr. FC&G added a refinement to our system:

This is an air circulation fan.  Obviously, it fits in the corner of a doorway.  What you can't see is that you can position the fan in a couple of different ways so that you are either blowing air into the room or drawing it out.  We draw the air out into the hallway and therefore up into the main part of the house (since the dryer is on the lower level and heat rises).

With the introduction of this fan, humid air doesn't collect in the laundry room; rather, it goes into the main part of the house.  While a laundry room probably can't handle the humidity from a load of laundry, the whole house certainly can.  In fact, a couple of loads of laundry vented inside during the winter helps reduce the need for a humidifier (or bathing in a whole tub of baby oil, if your skin gets dry like mine).

Some caveats:
  • Keep an eye on the humidity level in your house if you are venting inside.  You will notice variance depending on outdoor temp and dampness of your laundry.  For example, I can do probably three loads of jeans, towels, and other heavy clothes when the temps are in the 20s outside, because the house is so dry.  Come spring, a 60 degree day may not allow me to vent very much inside because the humidity gets unacceptable.
  • Consequently, use the baffle on the vent intelligently.  Perhaps you will want to dry a jeans load for 20 minutes or so with the baffle set to vent outside so you can get the worst of the moisture out, then vent inside for the rest of the cycle.  Experiment with your clothes, your dryer, and your house.
  • Speaking of houses, this really works best when you can distribute the heat and humidity through the whole house.  The doorway fan is one tool you have, but you can supplement by turning your whole house fan (not heat or AC) on to circulate air.  Also, you may not be terribly successful if your dryer is in an enclosed basement rather than an open lower level like ours.  My parents report that using just the vent baffle box in a basement many years ago resulted in an unacceptable level of humidity.  Those of you who have tri-level homes, as I do, or similar house plans may find this system easier to use.
The Analysis

Fast:  I think Mr. FC&G installed this entire system in about an hour, but he's handy like that.  (And he dances a mean tango, but I digress....)  However, the fan mounts on screws, so I could probably do that part.  The tricky part is climbing behind the dryer to access the vent tube and install the baffle box.

Cheap:  Yes, I should have kept the receipts.  My memory is that the entire system cost less than $50, and we do have the option of moving the doorway fan up to our bedroom over the summer to draw some of the heat out of there.  (Keep your naughty comments to yourself on that!)

Good:  This project brings the satisfaction of reducing the heat bill a bit and knowing that we aren't paying to dry a load of clothes, dumping all the heat outside, then paying again to heat the house.
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  1. I have a dryer in my bathroom and in a closet like space I just put a nylon stocking over the open hose and use it that way and the steam from the dryer comes out in to the kitchen and makes thehouse warm and cozy in the house.