Futures of laundromat dryers

[adam-aussie-vac]

Hey guys, I’m a little bit curious in today’s ever electrifying world (literally) I do wonder if laundromat size heat pump dryers would ever come into affect, as I know that they have electric laundromat style dryers But it does make me wonder as to how a heat pump laundromat dryer would work, as I’m kind of thinking they would use four or six smaller heat pump set ups to produce enough heat, and probably say after every 10th cycle, there’s some sort of coil washdown that sprays the evaporator and condenser coil to flush any accumulated lint, as I’m kind of thinking that a foam filter probably wouldn’t work in that situation, and maybe the condensed water could be used to help supply the Washers with water, although there might even be kind of a centralised heat pump system, where internally with each dryer, there is a condenser and evaporator, and then, depending on how many dryers are running, they have their control valves open to let the refrigerant flow through the coils, and the compressor ramps up accordingly

Am I thinking into things too much? Or is this something that will never happen due to the required drying speed of laundromat dryers?
Dryers involved

 

[me]

https://www.electroluxprofessional.com/references/laverie-verte-an-eco-responsible-laundrette/

 

[logixx]

They have been in existence for a while

https://www.miele.co.uk/p/commercial-tumble-dryers-3419.htm

 

[launderess]

Unimac: https://unimac.com/international/products/tumble-dryers/industrial-heat-pump-tumble-dryers/uhp/

IPSO: https://ipso.com/products/tumble-dryers/heatpump-tumblers/

https://aqualogic.com.au/wp-content/uploads/2022/10/IHP250-345-Heat-Pump-Tumble-Dryers-OPL.pdf

https://aqualogic.com.au/product/ipso-tumble-dryer-heatpump/

Danube: https://www.danube-international.co...6-11kg-capacity-launderette-heat-pump-dryers/

Fagor: https://www.fagorprofessional.com/en/laundry-machinery/industrial-dryers/heat-pump

Primus: https://primuslaundry.com/en/primus-introduces-brand-new-heat-pump-dryers/

Heat pump dryer technology for commercial/industrial dryers has been around for forty years or more in Europe. Thus it's not exactly something new as others have stated.

One main issue with laundromats however would come from cycle times. There is an exact ratio between washer/extractors and dryers of all types in various commercial/industrial or OPL laundries. What you don't want is things coming out of washer and having to sit about because a dryer isn't free.

Same applies in laundromat. We all know what it's like to be there with a load of wet wash and no dryers available. Often this is because people have wandered off and aren't there to take their washing out of dryer when it's done. That's easily sorted, just bung stuff into a cart and push it aside.

When dryers however cannot keep up with washing things become an issue. It can lead to poor ratings by customers of a laundromat and low satisfaction.

Depending upon capacity, heating source (which influences how fast things dry) usually washers usual ratio is 1.2 lbs of dryer capacity for every 1 lb of washer capacity. Or looking at it another way ratio of 1:2 to 1:4 (washers/dryers).

Normally it takes about it takes about 1200 BTU to evaporate 1 pound of water. Since a dryer is not 100% efficient, we use 2500 BTU/lb to make up for any inefficiencies.

Simple calculation would be Drying time (hrs.) equals (Load weight, lbs) x (% water retention) x (2500 BTU/lb) divided by (BTU per hour rating of dryer).

As with everything else more water extracted by washing machine (or separate extractor) leaving less residual moisture per load equals faster drying times.

In USA at least most laundromats make their money on dryers. New model washers/extractors that claim to have better extraction than machines of old (and they do) which in theory should shorten time in dryer.

Most laundromats in USA use either natural gas or propane for heating dryers. This is for various reasons but top of list would be for most areas of this country gas is cheaper than electricity. In terms of heating power gas ranks #1 followed by steam then electricity.

 

[launderess]

This bit from Electrolux pretty much sums things up:

https://www.electroluxprofessional.com/how-heat-pump-dryers-can-beat-the-energy-crisis/

Historically heat pump dryers (again used in Europe) couldn't match faster cycle times of vented dryers heating with gas, steam or electricity. This lead to slower productivity unless other ways were found to compensate. So on the one hand energy use did (or does) decrease when using heat pump dryers, but since cycle times were longer this came at a trade off.

Electrolux claims latest heat pump dryers with modern technology can dry a full load taking only five or maybe ten minutes longer than a vented dryer.

 

[henene4]

Miele actually rates their dryers for explicit times (here for the 10kg/22lbs 8.9cuft models):
- Electric with 13.5kW heating in 24min
- Gas with 15kW heating in 23min
- HP with 10kW heating, 5kW total load in 33min

The biggest issue is actually size.
In Europe it's about 50/50, but I don't know any US laundromat that does not have stacked dryers.
There currently are not any stacked HP dryers for commercial use.
Given the size and weight of the heat pump module for Mieles HP dryers, constructing something like that for 2 dryers in the space of one is gonna be TIGHT.

If you go even further into the commercial space, to the tunnel washer sizing, creating heat exchangers for that size, that's a whole different story.
Also heating for those kinds of washers and water supplies is technically possible in part with heat pumps and resistive heating.

But I think that's gonna be one of the areas where hydrogen will be one of the alternatives seeing adoption.
Getting the temperatures and power densities needed are just a step beyond electric capabilities.

I think laundromats will go towards heatpump more likely.
A 30kW connection for each dryer stack is just not feasible. But given their location, there probably won't be a hydrogen grid present and a "island" hydrogen solution will be too complicated for a comparably "small" installation.
The ELux HP dryer is already just about 27" wide. That would still cut the number of dryers in half, but they more than likely will find a solution like cutting a few smaller washers.
For the EU, where most laundromat washers are "compact", ELux already has a drop in solution. Their TD6-7 HP is quicker that the matching WH6-6 and stackable. It is very expensive, but that's a matter of mass production more than anything.
And I once did the calculations, and breaking down the cost over lifetime, you can just about get them as cheap per payment as a gas dryer if you are willing to sacrifice a bit of profit.

Industrial installations will go towards a gas alternative like hydrogen and probably a lot towards more aggressive heat capturing and reuse systems.
Probably multi stage systems of air-to-air, air-to-water and then air-to-water via heatpump aswell as water-to-water via heatpump.

 

[launderess]

"In Europe it's about 50/50, but I don't know any US laundromat that does not have stacked dryers."

While not common yes, there are laundromats with large dryers which by necessity stand alone.

More and more American laundromats are going with 40lb to 80lb washer/extractor. At some point it makes sense to have one or more large, huge or jumbo dryers so entire load from those larger washers will fit into one dryer.

Customers and or wash/fold service also want larger washers and dryers for doing things such as large queen or king sized duvets or maybe more than one of smaller twin or full.

https://kingpelicanlaundromat.com/self-service/

https://www.wisconsinhistory.org/Records/Image/IM110406

Then you simply have those with very large loads they want done all at one go. At our local laundromat have seen people time and time again cram lone 60lb washer until nothing else will fit in drum. Smart people know they cannot fit all that wash into one of the stacked dryer and split load. Others don't have a clue and force all that washing into one dryer.

At local laundromat the lone 60

 

[launderess]

For tunnel (batch) washer and even single or divided pocket washer/extractors most commercial/industrial laundries go with steam where heating of water is necessary over electric resistive. There are many reasons for this but IIRC steam gives up more heat faster than other ways and you don't have bother of scale and whatever else harms or builds up on heating elements.

Commercial laundries also use various methods of reclaiming heat from waste water to preheat cold water before it reaches washer. Such heat exchange saves energy.

Above is coupled with fact most laundries do not start from cold water and do "profile" washes. There might be a cool or warm flush/pre-wash but commercial/industrial laundries supply washers with "hot" water at 140F to 160F or above right out of taps so to speak.

 

[daveamkrayoguy]

Well I have to wonder about the ban on gas appliances and elimination of gas pipelines I keep hearing about so dryers here seem merely destined to be just electric from what I can surmise, and a lot of electricity needed for those laundry mats then...

-- Dave

 

[launderess]

Generally because it involves public health laundries and other places are given wider scope on many issues. This includes current hate against natural gas or other fossil fuels.

Current federal and or local regulations and so forth already have driven up costs for laundries of all sorts. This explains why so many laundromats and laundries are closing. This and or the massive consolidation that has been going on for a few decades. You can only charge but so much per pound of wash.

Laundries have responded by using more energy efficient equipment. Batch/tunnel washers for instance can dramatically reduce water and energy use.

 

[henene4]

Thing is even with steam heating - creating steam is a very high energy high temp process.
Doing it via resistive heating is very energy intensive, and while ultra high temp heat pumps are being developed, they aren't there yet.
Most heat pump technologies end at a max 180F.

Steam heating is usually just gas heating at a different location.
Steam is easier and safer to transport, especially when many locations need steam already - like finishing steps later in a laundry process.
Having gas lines going everywhere on a commercial level and dealing with exhaust can get complicated quickly, so centralised steam production and distribution is often just more efficient, more flexible and cheaper.

And I can just say it time and time again - what ever way we can completely eradicate green house gas emissions by the end of the century is fine with me.

And natural gas combustion just is a green house gas emitting process.
And so far, heatpumps are the best way to replace that.