Venting a dehumidifier into a dryer vent?

Question

I just moved into a highrise with no washer/dryer. Instead of getting a massive washer/dryer combo, I'm planning on getting a 0.9cu washer and a heated drying rack to prevent wear on clothes and also save on water/electricity. I'm a little concerned about mold, so I'd like to get a dehumidifier to keep the air dry in the utility closet.

Can I just hook the condensed water output to the dryer vent? If I'm understanding correctly, the dehumidifier collects and expels water, and the dryer expels lint (and maybe water? I'm very uneducated when it comes to this) into the dryer vent. Does my planned setup make sense?

There's also the utility room with the boiler/hvac which drains into a hole. I could run a hose into there I have to.

Would love some input!!

Answer 1

Venting a dehumidifier into a dryer vent would be useless.

You WANT the "exhaust air" from a dehumidifier - that's the air you just paid to make warm and dry.

You only need to get rid of the water it produces, and that requires a drain, not an air vent.

The disused dryer vent should be capped off, so it does not serve as an air leak or a passage for bugs, etc.

Answer 2

How these appliances work

A normal dryer blasts out a considerable stream of air which is hot, wet and contains airborne lint. This has a bad side effect: it pulls outside air into your house through every other orifice and leak, which then needs to be conditioned and de/humidified.

A dehumidifier circulates air in the room, and ejects liquid water into a drain pan which you empty once or twice a day. Some can pump it down a normal water drain.

Do not put water down an air vent. It is NOT watertight, and may go uphill, which air will do and water will not.

To dry clothes, you must remove all the water.

This might be 20 pounds of water. 8.3 pounds per gallon or 1 kilo per litre.

To vaporize one pound of water you need 970 BTU. About 2000 BTU for a kilo.

That means your dehumidifier must pull it out of the air if you air dry. If you don't, the room will instantly mildew and so will your clothes.

Fortunately a dehumidifier is a heat pump, and heat pumps are 200-600% efficient at this task. This will be much more efficient than an electric dryer. Further, since you are not sucking outside air into the house that then needs conditioning, that is another 100-300% efficiency gain vs plain dryers. Interesting, I thought you were a nut, but you're onto something!

Answer 3

Interesting thought. Running the condensed dehumidifier water into the dryer vent directly is not good. Although center dryer air starts out highly moist the end of the cycle dryers out the vent tube. Since you’ll always have water you’ll miss the drying and all forms of wonderful growth will occur. Think Amazon rain forest. You could run a small water hose through the dryer hose duct all the way to the outside, but a bit hidden (not hanging out conspicuously). You’ll need to air-seal the hose entering the vent duct AND be sure all drains down hill. However, you mentioned the HVAC drain pan. That would be a great place to run the water but then your pan is always wet (Amazon R F). Though you could install a small lip in the pan to send water out the pan drain and not into the pan. Regardless, allowing your dryer to vent into the dehumidifier inlet area and allow the exiting dehumidified air to flow directly into the dryer inlet air area would work. Your dryer could also run in non heated air mode. All this said, you could just drill a hole into the apartment below and let them deal with the excess water. :)