What is the difference between vented, condenser and heat pump clothes dryers?

Feature image credit - Marshall Williams via Unsplash.com

GadgetGuy has been looking at the tech difference between vented, condenser and heat pump clothes dryers. Not necessarily from the standpoint of what is best but what works in different circumstances. In other words. What are the advantages and trade-offs?

These days when you go into Hardly Normal you will be faced with over 50 choices ranging from a $380 Simpson 4.5kg timer vented dryer to about $800 (the latter have smart sensors and programs), several condenser dryers from $799 to $1599, and nearly 30 heat pump dryers from $1099 to $4499! The range is mind-boggling.

Then there are the washer/dryer combos. These are space-saving devices – one cabinet to do two things.

We look at the tech difference between vented, condenser and heat pump clothes dryers and discover that in most cases all you need is a typcial vented dryer.

Note: For this article, we will use Fisher and Paykel references. This is for convenience, not necessarily an endorsement.

Vented dryers (Simpson)

difference between vented, condenser and heat pump clothes dryers

We are all familiar with this type. It is an open system. A fan draws external air over a heating coil, blows it through the drum and expels hot, moist air out a vent. Air should vent to the outside – otherwise it can get hot and steamy in enclosed spaces.

These are by far the fastest, drying a 4-5-6kg load of sheets or towels in under an hour. Regardless of the 2-to-3-star energy rating, they dry faster and use less overall electricity per kg/minute.

Upside: Cheaper to make and buy. Quick-drying. Stackable or wall mount. Good energy $ per kg/minute drying time ratio.

Downside: hot, moist air needs to go somewhere so vent if you can or open a window in the laundry. Shorter replacement cycles. Not as gentle on clothes as one heat/time fits all. Can ‘ball’ clothes leaving damp patches inside.

Sensor vented dryers (Fisher and Paykel)

difference between vented, condenser and heat pump clothes dryers

Some add smart sensors, programs, auto-reverse (stops balling of clothes) and delayed timer start to ensure clothes are not overdried or use low tariff electricity periods. These are better and stretching to this level will get you the best heater/dryer.

Upside: Fastest. Stacked or wall-mounted. Gentler on clothes as you can select programs. Even more energy efficient on an energy $ per kg/minute drying time ratio.

Downside: hot, moist air needs to go somewhere. More complex electronics to go wrong.

Condenser dryers

difference between vented, condenser and heat pump clothes dryers

A condenser dryer is a closed system. Air is blown over a heating coil and into the tumble drum. It is expelled to a condenser chamber where water is extracted, and the dry air is heated and goes around again. The collected water reservoir needs frequent emptying.

My experience with a combo washing machine and condenser dryer in the 90s was frustrating. Why? While the washer may have been able to wash 8kg, the dryer was only able to dry 5kg. And the drying time was often several hours, especially for sheets and towels. We found that heavier items tended to be dry on the outside and wet on the inside.

So, condensers, especially combos, are very, very slow. They also use more energy (typically 2-star) than a vented dryer due to heating and condensing air.

Upside: closed system – no venting

Downside: Slow, need to empty a water reservoir, weigh a lot and cannot be wall-mounted.  Poor energy $ per kg/minute drying time ratio.

Heat Pump dryers

difference between vented, condenser and heat pump clothes dryers

A heat pump is a type of condenser dryer without a heating coil. It is a closed system mini air-conditioning/fridge unit. A compressor ‘compresses’ refrigerant gas and in the process of blowing air through the coils hot air extracted is blown into the tumble drum and the process repeats. Water is collected from the coils. That is why it is cold in a fridge and hot outside it.

A compressor is way more energy efficient (usually 7-9 stars) than a heating coil, but performance can be affected by the ambient air temperature and humidity. Heat pumps also need to empty a water reservoir.

They are gentlest on clothes as the use far lower temperatures, but they can take even longer than condenser systems.

Upside: low energy use. Said to be gentler on clothes.

Downside: Long time to dry. Cannot be wall-mounted. Need to empty a water reservoir. A lot of tech to go wrong.

The heat pump on the right does not have a heater coil

GadgetGuy’s take:

Q: What is the difference between vented, condenser and heat pump clothes dryers? A: Money!

Joe and Jane Average with 2.5 kids will need the largest capacity they can get – usually 7kg if you want to plug it into a domestic power point. Our best advice is to stretch to a vented sensor dryer if you can afford to. If not a standard dryer works well!

But, if:

  • You have a closed in laundry/bathroom/cabinet inside a closed-in apartment then a vented or sensor dryer (vented outside) is still the best choice. Often the vent can be easily connected to the mandatory extraction venting fan found in most apartments.
  • Not then it is a choice of condenser or heat pump at a greater cost but remember that these are generally too heavy to wall mount so floor space may be a problem.
  • You are like the typical family and want to wash several loads (sheets, towels, garments) then you will want the fastest washer, and fastest dryer – vented and sensor win again.

We won’t get into a debate on whether you should airdry clothes on a clothesline, but common sense says this is the gentlest and cheapest of all even if it is a chore and wet days can cause problems. See our article on how to get the best out of a dryer – any dryer – here.