Aircon vs dehumidifier in this weather

[Jeff Layman]

I meant 1200 x 600mm, not 600 x 400!

[Jeff Layman]

I paid £358 for this in June! It's now £240. :-(

It works very well and is quiet with the fan at low speed. It has easily dealt with the 30°C+ outside temperature, keeping our 75m^3 lounge to

22°C even at low speed.

[The Natural Philosopher]

Not only reportedly, actually.

I have been more uncomfortable at 35°C 100% RH than at 50°C and 12% RH. Provided you have water to drink in the latter case.

TBH you have a problem in that sealing the room will probably lead to increased temperatures

Car aircon works the way it does because of that.

[Pamela]

I vent through an open casement window not a fanlight. There are kits but most need sticky tape, like the one below. They don't seem very practical for just a week or so because cleaning the tape residue would be a nuisance.

[Pamela]

In the end, two part aircon units are the way to go. The portable units are not all that portable which means mine gets used in only one (maybe two) rooms. Also my portable unit is definitely not quiet.

[Jeff Layman]

Mine is a casement window which opens outwards. I don't know of any portable A/Cs where the vent hose would reach a fanlight. All I need do is open the window and push the polycarbonate sheet onto the matching Velcro on the frame. No sticky tape required, and if the Velcro wears out it'll be easy to replace. I can get a photo sometime tomorrow if you're interested.

There are kits

[me9]

>

That's a single box one with a huge hose.

[Jeff Layman]

Indeed it is, but you asked about "a suitable portable replacement without an astronomic price tag". This is more expensive, but might be suitable for your purpose:

[Paul]

Tried it. No is the answer.

I've tried a number of pathological cases, just for fun. I tried a steamed up bathroom. I tried running the dehumidifier for a couple days in the basement. And a "normal" application in the kitchen. Virtually none of the outcomes was acceptable. (Too hot or too stinky.)

*******

Air conditioning obviously does two things. Reduce humidity and cool the air.

Now, the neat thing is, the next day when it gets hot, if the house is sitting at 40% RH, you are still comfortable, even if the house hits 85F to 90F. But once the humidity starts to climb again (all those tea towels drying out), you're right back where you started.

So, two things, humidity and cooling, and humidity control has the benefit, it works a tiny bit the next day to keep you happy.

When you have plaster walls, those "buffer" moisture more than gypsum board walls. It may take a few days, to shift the house moisture content they way you'd like it.

*******

If you cool a house too quickly, it makes the house feel "clammy". It is not really a pleasant result. This happens, when your AC unit is 2X the proper capacity.

If you cool a house to the endpoint in 3 hours, that is too fast. You want to cool the house in 6 hours, as that leaves time for the AC to remove the water from the air. Now, you're comfortable. And when the next day comes, the low humidity takes the sting out of the heat. For about half the day. (This assumes lekky is time-of-day billed, and you may not want to run AC when lekky is expensive.)

If you fit a circulation fan, into the doorway of the room with "too much AC unit", that helps extend the square footage you are cooling, and the result is "less clammy" and drier. But it takes longer of course.

I could probably cool half my house with 10,000 BTU and a couple circulation fans to spread the joy. Or, I could use two 6000 BTU, one per bedroom, two circulation fans, and send some of the cooled air down the hallway, to the other half of the house. The other half of the house would not be cool, but it would take the edge off the heat.

And you don't need the yard wide "box fans" for the circulation. You could go with a 15" desk fan sort of thing. Still noisy, but not "box fan" noisy.

*******

If you put a 10,000 BTU window AC into a single room, that would be too much. And in three hours, it would feel "cold and clammy" in the room. Such an aircon is also too noisy. If you've ever been in a motel room with one of those, you'd know how much sleep you get with one of those.

When buying an AC then, you have to read the package ratings, to get some idea whether it's a good fit or not. Preferably, ask someone at the store, if the staff aren't circus clowns (Best Buy).

Buying a single 6000 BTU, is generally a waste of time. You would be buying smaller ones like that, with a multi-room plan of attack. You might even have cool room, warm room, cool room, for your deployment, assuming the warm room is empty and has no occupant.

Usually when you want an AC, none are left. Which means, typically when there is trouble, you're left with "table scraps". This may affect your ability to implement your plan.

Even for whole house AC, the unit you want may not be available. That's how I ended up with a too-big aircon and "clammy feeling". However, a year later, enough refrigerant had leaked out, the cooling time was taking 2x as long, and it was "perfect". Just took a year of leakage to do the job :-) You don't get lucky like that, all that often.

Paul

[John J]

Try contacting one of your local industrial training/assessment organisations and ask if they can tell you who's qualified near you. They might be reluctant to actually recommend but knowing a few local names will give you a good point of entry.

[Bob Martin]

Google "Comfort Index".

[Animal]

there are generally usable replacement gases

[Animal]

Reducing RH certainly improves comfort during heat. Don't know why you'd want to seal the room, it's a view I see repeatedly.

[Andrew]

Because you will never reduce the humidity levels inside a room if the outside air is more humid and the windows and doors are left open.

[Animal]

sealing a room or not & opening exterior windows or not are 2 separate things.

[Hyper-pop]

I think you're right Theo - I believe that's the exact reason for the inflated prices. I read somewhere that the UK has about 4,000 F-gas qualified people, and the demand is expected to be over 20,000 by 2027. I'm not sure that the non F-gas refrigerants are the solution. They are much more environmentally friendly, but are highly flammable - R290 is propane! The flammability means that the total amount permitted in the in the system is much lower - see

[Hyper-pop]

There's a couple of directories maintained by the people who manage the F-gas certifications. There a good starting point, but do list companies who are business-to business only, so not all entries are useful:

[Smolley]

Ammonia is an efficient refrigerant used in food processing and preservation, as well as many other refrigeration and air-conditioning processes. Ammonia has desirable characteristics as a refrigerant, which have been well known for over a century. It is corrosive and hazardous when released in large quantities.