No Bosch is not the only one, I have an Asko condenser and I believe Miele also makes one.

But get up and shake yourself off. It's not the answer to placing a dryer anywhere.

a) you need 220V service

b) despite what you may hope, cond. dryers don't work well in small, enclosed spaces, like closed closets.

That said, I have one in a large bathroom and think it's fine, for a condenser dryer.

Regular dryers work better, IMO, but of course if you don't want to blow all that heated air out of your house, or can't, then your only option is a cond., which is why I have one.

They are generally more expensive to purchase, and slightly less efficient to run, but they do a very satisfactory job of drying your clothes. I think they are also smaller than typical US dryers because they were designed to be paired with the smaller-sized Euro-type FLs. (Though as Asko and Miele are going to larger FLS, perhaps they've up-sized the condenser dryers in their lines.)

And because they are meant to be paired with high-efficiency FLs, I don't think they would work as well with clothes washed a regular TL because there is much more residual water in clothes that aren't processed/spun at high speed. (Similarly if your laundry practices, no matter what machine you have, do not include high-speed spins - at least 1000-1200 rpm - then you may have difficulty with a condenser being adequate for the job.)

Condenser dryers work by having two independent air paths. They draw in room air, heat it, pass it through the clothes and exhaust it out through a condenser. As the warm moist air passes through the condenser, it is cooled and the water vapor it carries falls out as droplets. The droplets are collected and pumped to a reservoir that must be emptied after every load. At the same time regular room air flows over the condenser and acts as the thermocline to cause condensation. Inevitably use of a cond. dryer causes an increase in ambient room air temps (which is why I have mine a bathroom - to heat it), and a slight increase in humidity, as well.

And that illustrates the potential choke point on the system. If you live in an area with very warm temps, especially warm humid temps, (or have the dryer in a small enclosed space like a closet) you will have insufficient temperature differential for efficient drying. Unless you are running your A/C system, which strikes me as a pricey way to dry your clothes!

I only have the condenser dryer and mainly use it in emergencies as I dry outside almost entirely, year round. But every now and then I need something in a hurry, and unfortunately it's usually a hot, rainy, poor-drying day and so my condenser dryer is less efficient than it normally is. (Occasionally during the winter when the outside temps are fierce and it's snowing, I'll use the dryer - then the low humidity and steep temp differential make it work like a champ.)

Some cond. dryers may require a hard connection to a drain for the condensate, but mine is collected in a reservoir and dumped manually.

Cleaning the condenser is a routine, but very icky job. My manual says it should be done once or twice a year. However, I have to do it about every week or so if I dry all my laundry in the dryer. If it wasn't icky, I wouldn't mind, but I loathe doing it.

And, of course, condensers are always electric, not gas.

Does that answer your questions?
L

Bosch's ventless dryers assume they'll be installed next to a washing machine, or at least a drain, and they have a thin hose that drains water extracted from the clothes that normally drains wherever the washer does. Some other brands have an option to drain into a removable pan or container, which must be emptied every few uses (a light comes on to alert the user, and the dryer won't run until it's emptied.)

The Bosch condenser coils need occasion cleaning (a few times per year). That aside, it works well, and has (slightly) larger capacity then other currently-available condensation dryers.

Thanks. The tip about needing a HE washer is priceless.

About how much does it heat up the surrounding room? Are we talking 5 degrees or 15 or...?

In addition to you two, I've also seen online some people saying the condenser needs occasional cleaning, and others saying it needs cleaning frequently (once a week, to me, is very frequently). Is the frequency of it dependent on the brand? Why do people say such different things about the frequency? I wouldn't mind doing it, say, once a month, but once a week is a bit much.

My all-in-one LG condense dries also. We moved a standard stacked washer/dryer unit out of the kitchen and bought this unit for another closet in the house. We have the water hook-ups and a drain pipe. That's all that is needed. Dries wonderfully. Wrinkly clothes are about the only downside that I experience. Removing them quickly after the cycle finishes means they will be HOT and less wrinkly. No biggie.

I think the need to clean the condenser part more frequently depends on:

a) the efficiency of the filters in the hot air path. All filters retard air flow to some extent and it's a trade-off between "perfect" lint, hair and particulate filtration and efficiency of air movement. I expect some machines do it better than most, and some individual machines may have small anomalies in the seating of the filter that result in more pass through of gunk that winds up in the condenser.

b) the kind of fabrics being dried and the amount of hair and pet fur on the items. Most hair and fur is removed in the dryer, not the washer, so if you have a lot of pets it may be more of a problem for you. (I have 9 cats and 2 bunnies now) so my results may be skewed by that.) OTOH, I've had my machine since before I had indoor cats and when I only had a dog with a short, tight coat (Rhodesian Ridgeback) and had the same issue. My fabrics have always been comparable, with them mostly being cotton, w/o synthetic content.

My manual says twice a year, I have to do it at least once per week if I am fully drying 10-15 loads per week.

The cleaning is not onerous, just icky. On my machine you remove the bottom section of the machine and extract the condenser. Then you run a lot of water over the plates to dislodge the slimy gunk. If that was all, I wouldn't hate it so much. But in practice, I find that truly cleaning the plates requires painstaking scraping using a bent coat hanger thingy I made up to dislodge it all completely.

The machine will (mostly) still run with a light to moderate buildup on the condenser but you pay for it in steep loss of efficiency. Eventually the machine senses the lack of cooling in the condenser and shuts down. (Usually when I'm in a hurry, darn it!)

If a condenser dryer is your only choice then it easily fills the need. In my case I hang out 99% of my laundry, about 95% of the time so the demands I place on my condenser are not too much. If I dryed all my clothes in it, especially in warm weather, I think I would find it unsatisfactory. As it happens I only resort to complete indoor drying in the few years (like this one) when unsually snowy weather makes line drying too much of challenge. And as I mentioned, I don't mind the added heat gain from the dryer in the winter.

I woujld say it raises the temps in the bathroom (10 X 20 foot space) about 10-15 degrees. Keep in mind, though, that my heating situation is very atypical. We heat only with wood and our house is generally much cooler than most people would tolerate in the winter: generally around 50F. But the heat gain is significant enough that when I'm running thr dryer for full-drying (as opposed to the 15 minutes of cold fluff that I do for every load before hanging it out), I notice the boost in temps in the entire first floor. And on hot, muggy days in the summer, I avoid drying at all during the afternoon and evening since it makes the house more uncomfortable. If we had ordinary central heat or A/C, I think the temp effects would be handled by the HVAC system and not noticeable to occupants. But that doesn't mean that they don't exist, nor that you are not boosting your energy costs to handle them. Since we have no automatic HVAC system, I think we are experiencing the true, unmoderated, effects more than most users.

HTH,
L