View Full Version : Dryer heat recovery ?
Howard
02-23-2001, 06:56 PM
We all spend lots of money heating cold air and venting it out as hot moist air. Does anyone know of a system to cross exhange fresh air with the vented hot moist air to recover energy. I'm looking to design a new laundry and want to see if it makes sense to manifold the dryers rather than vent them straight out the roof one by one. Figure if manifolded I could install some sort of blower and heat exchanger. Any ideas?
Howard
03-08-2001, 05:51 PM
Come on guys, doesn't anyone have ideas on this???
petefritz
03-10-2001, 01:57 AM
Howard, are you wanting to heat air for the l'mat durring winter or you want to heat water?
You might get both,,, it would take a huge amount of copper tubing, but you could wrap the exhaust tubes from each dryer and send the heated water thru heaters or water tank.
If you had a manifold system for your dryers, then you could run the pipes inside that, it would not reduce the air flow. The air itself comming out of the dryers is just to humid to deal with directly.
I read an article awhile back, the guy wrapped his sewer lines in copper tubing for a heat exchange system.
My thought on this for winter heat is(since you are building new and can incorporate it) was to build an extra room large enough to handle the quantity of air and put the same type of filters(or design/build your own)the dryers use to collect any bypass lint(since they clean themselves) then have a small dehumidifier to cycle a portion of the air thru according to your weather, then bring the air into the activity space(you will get the benefit of the dehumidifier operating heat as well). The only problem is regulating the amount of air you bring in and how much to discharge outside.
Just my 2¢
Marianne
03-11-2001, 12:00 PM
My dryers are built into enclosed rooms that allow work space behind them. The makeup air also dumps into those rooms. On a cold night with no dryer activity the temperature inside that room can go below freezing. When the dryers are working the heat radiating from the vent stacks warms the room and preheats the makeup air.
I don't think this is an unusual arrangement but it is still a valuable contribution to the effeciency of the dryers.
Howard
03-11-2001, 12:26 PM
You are correct, it is not unusual, and it is a start on reclaiming some heat - but not a very efficient way of doing it. If on one of those cold days you climb to the top of your roof you will see plumes of steam coming out of the vent stacks. If you put your hand under one of those you will feel very hot air - that is all energy that you are wasting. Put another way - that is your money venting to the sky! There has to be a way to reclaim almost all of this.
Marianne,
Do you have a damper system to close the shutters on the make-up air at night when you close or are you open 24/7?