A ventless dryer that reuses heat for lower energy use.
also: heat-pump tumble dryer
The basics
What to know about clothes dryers
Drum, heat and a way out
A clothes dryer is a rotating drum, a heat source, a blower and a route for water to leave. That last item is the whole story, because how a machine disposes of the moisture it pulls from your laundry decides where it can stand, what it costs to run and how long a load takes. Full size drums hold 7.0 to 7.5 cubic feet; compact ventless models sit nearer 4.0. Heat comes either from electric resistance, where current passes through a coil, or from a gas burner. Moisture leaves either through a duct to the outdoors or through a heat exchanger that condenses it into water you pour away.
Vented, and how the heat is made
An Electric Vented Dryer and a Gas Vented Dryer both heat room air to roughly 150 to 175 F, blow it through the tumbling load and push the humid, linty air outside through a 4 inch duct. Fast, simple, and it throws heated indoor air out of your house at the same time. A Condenser Dryer keeps that air inside the cabinet, cools it across a heat exchanger until moisture drops out, then reheats it, sending the water to a tank or a drain. A Heat-Pump Dryer performs the same condensing trick but adds a refrigerant circuit, the technology a refrigerator uses, to carry the heat it just removed back into the drum instead of wasting it. Recycled heat is why a heat pump uses roughly 1 to 1.5 kilowatt hours per load against 2.5 to 4 for a vented electric model, and why it dries at 120 to 140 F, kinder to elastic and printed graphics. Almost all dry by sensor: metal bars in the drum read how well damp fabric conducts electricity and end the cycle when it stops.
Let the room choose
Let the room choose first. Where a 240 volt, 30 amp outlet and an exterior wall within duct range already exist, a vented electric machine is the cheapest to buy and the quickest to finish, at 40 to 60 minutes a load. Where a gas line already reaches the spot, gas usually costs less per load, though that ratio varies by region and season, so read your own two bills first. An interior closet, a condo with no exterior wall, or a rental you cannot drill takes venting off the table and leaves a heat pump or a condenser. Heat pump models also answer the case where no 240 volt circuit exists, since many run from an ordinary 120 volt, 15 amp socket. Five or more loads a week plus expensive electricity make the heat pump premium land fastest.
The heat pump asks for patience
The heat pump asks for money and patience. Expect several hundred dollars more up front, 90 to 140 minutes a load instead of 45, a second and sometimes third filter to clean, and a sealed refrigerant circuit only a qualified technician may open. A condenser without the heat pump costs less and dries at full temperature, but it dumps the heat it removed into the laundry room. This is welcome in February and miserable in July. Vented machines hand you the opposite bill: speed and cheap repairs in exchange for a duct that is both a maintenance job and a safety one. Close to 13,000 home fires a year in the US involve a clothes dryer, and failure to clean is the leading cause. A vented machine also pulls 100 to 200 cubic feet of heated indoor air a minute out of the house, drawing cold outside air in to replace it, a heating bill nobody itemizes for you.
Look inside the drum
Look inside the drum before you look at the control panel. Sensor bars, two dull metal strips usually set near the lint filter, mean the machine can stop when clothes are dry. A dryer running on a timer alone will overcook or underdry every mixed load. A stainless drum will not chip and snag the way a painted one does once a zipper finds it. Read the maximum duct length in the installation manual, quoted in equivalent feet, where each 90 degree elbow counts as about 5 feet of straight pipe. A model permitting 65 has more blower behind it than one capped at 25. Check where the exhaust connector sits, since a rear centered outlet pushes the cabinet 5 or 6 inches off the wall unless you fit a shallow periscope elbow. Confirm the door reverses if your room needs it, look for a low heat program near 125 F, and on a heat pump ask how the evaporator gets cleaned and what the compressor warranty runs.
Airflow is the whole job
Airflow is the entire maintenance job. Pull the lint screen every single load, because a screen half covered can add 20 to 30 percent to cycle time. Heat the air is not carrying away stays in the cabinet. Wash that screen with soap and a soft brush every few months too, since dryer sheets leave a film you cannot see. Once a year, disconnect the duct, clean its whole length and the outdoor hood, and watch the hood flap open fully while the machine runs. Wipe the sensor bars with rubbing alcohol at the same time, since fabric softener glazes them and a glazed sensor calls a damp load finished. Never load anything carrying cooking oil, solvent or wax, even after washing, because oil keeps oxidizing and making heat inside a warm folded pile long after the drum stops.
Buyer checklist
Before you buy clothes dryers
A major appliance must fit the space, the utilities and the service network. Running cost and repair access belong in the first comparison.
01
Measure the full installation
Include doors, handles, hoses, vents, clearance, service access and the delivery path, not only the cabinet opening.
02
Confirm every utility
Check voltage, circuit, plug, water, drain, gas and ventilation requirements against the exact model and local rules.
03
Compare ongoing use
Use the local energy or water label and include filters, detergent, bags and other consumables.
04
Check parts and service
Look for local technicians, realistic warranty coverage and the availability and price of common replacement parts.
Pair the drum to the washer at roughly 1.5 to 2 times its volume: a 4.5 cubic foot washer wants 7.0 to 7.4 cubic feet of dryer. Wet laundry that cannot fall freely dries unevenly and adds 20 minutes or more to every cycle.
Measure the duct run in equivalent feet, counting each 90 degree bend as about 5 feet of straight pipe and each 45 as 2.5. Manuals cap the total, often somewhere between 25 and 65 feet depending on duct size and hood type, and going past the cap makes the machine run hot and slow.
Use 4 inch rigid or semi rigid metal duct only. Flexible foil and plastic sag, catch lint in every ridge and are banned for dryer exhaust in many jurisdictions, so check your local code before you buy materials.
A full size cabinet is 27 inches wide and 30 to 32 inches deep, and a rear centered exhaust pushes it 5 to 6 inches off the wall unless you fit a shallow periscope elbow. Allow another 24 inches in front for the door.
Confirm the supply before delivery. Electric vented models need a dedicated 240 volt, 30 amp circuit and a cord matching your 3 or 4 prong outlet, which is normally sold separately. Gas models need a shutoff within reach plus a 120 volt outlet. Many heat pump models run from a standard 120 volt, 15 amp socket.
Ventless machines still need somewhere to put the water: plan on emptying 2 to 4 quarts a load from the tank, or run the drain hose at the height the manual specifies.
Care
Caring for clothes dryers
Clear the lint screen every load without exception. A screen half covered can add 20 to 30 percent to cycle time. The heat that airflow is no longer carrying away builds up in the cabinet instead.
Every few months, hold the screen under running water. If the water pools rather than passing through, the invisible film from dryer sheets is blocking it: scrub with warm water, dish soap and a soft brush, then dry it before refitting.
Clean the whole duct and the outdoor hood once a year, and watch the hood flap open fully while the dryer runs. Duct fires start in ducts nobody has opened, and a restricted duct also blows the thermal fuse, a one time safety part that has to be replaced rather than reset.
Wipe the sensor bars inside the drum with rubbing alcohol every few months. Fabric softener glazes the metal, and a glazed sensor reads the load as dry while it is still damp.
On a heat pump machine, clean the secondary filter and the evaporator on the schedule in the manual. A coated evaporator can double cycle time, and it is the most skipped job on this kind of dryer.
Never dry anything carrying cooking oil, solvent or wax, even after a wash. Oil keeps oxidizing and generating heat inside a warm folded pile long after the drum has stopped turning.
Questions
Common questions
How long should a load take?
Count on 40 to 60 minutes for a vented machine, 90 to 140 for a heat pump, and something between for a plain condenser. Judge yours against that. When a vented dryer that used to finish in 50 minutes starts taking 90, nothing inside it has failed: the lint screen, the duct or the outside hood is restricted, and heat is piling up where air should be moving.
Is a heat pump dryer worth the extra money?
Do the arithmetic on your own use. It saves roughly 1.5 to 2.5 kilowatt hours a load, so 5 loads a week comes to 400 to 600 kilowatt hours a year, worth around 60 to 100 dollars at typical US rates. Against a price premium of 400 to 700 dollars, payback lands at 5 to 10 years. Heavy laundry and costly electricity shorten that; a single person stretches it past the machine's life.
Gas or electric?
Whichever is already installed, nine times out of ten. Adding a gas line or a 240 volt circuit runs several hundred dollars and wipes out years of running savings. Where both exist, compare your own bills: gas usually wins on cost per load in markets where gas is cheap relative to electricity. But that relationship shifts by region and by season, so check rather than assume.
Can I vent a dryer indoors instead?
Never with a gas dryer, under any circumstances, because the exhaust carries combustion products into the room. With an electric dryer, indoor lint traps are sold. They are still a bad idea: one load puts about a gallon of water into the air, which ends up on windows, walls and drywall. Many local codes prohibit indoor venting outright, so check yours before buying a kit.
Do I have to buy the dryer that matches my washer?
Functionally, no. Any dryer dries any load. Matching counts in two places. Stacking needs the kit approved for that exact pair and is really unsafe improvised. Capacity needs roughly 1.5 to 2 times the washer's cubic feet, so a dryer much smaller than that will be packed. If you never stack, choose the washer on cleaning and the dryer on venting.
Why do some clothes come out damp when the cycle ends?
Sensor drying reads an average, so one heavy waistband or a bath towel mixed with shirts finishes wet while the rest is done. Sorting by weight removes most of it. When a whole even load comes out damp, work through the causes in order: glazed sensor bars, a blocked screen or duct, then a washer that stopped spinning to full speed.
Who has to install it, and what can I do myself?
Plugging an electric dryer into an existing matching outlet and clamping on a metal duct is homeowner work. Anything involving gas belongs to a licensed installer: connecting the line, leak testing it, and converting between natural gas and propane, which needs the correct burner orifice. Running a new 240 volt circuit, or hardwiring instead of plugging in, is licensed electrician work in most jurisdictions.
What usually breaks first?
Belts, drum rollers and the thermal fuse, all cheap parts on a vented machine. That is why vented dryers often reach 12 to 15 years. Read a blown thermal fuse as a message, not a fault. It opens because the machine overheated, and restricted airflow is nearly always the reason. Fit a new fuse without clearing the duct and you will fit another one soon.
