Question Air-Conditioning, Use and care.

[Notebook]

Just bought an air-conditioner from Amazon, https://www.inventorairconditioner....ble-air-conditioners/cool-air-cooler-8000-btu

Had a couple of hot days(for Northern England), and my 87 year old mother, who has dementia, was exhausted by it. Had trouble getting her out of the seat and into bed, so needed to do something.

Never had one before, fairly straight forward to assemble, exhaust-hose is stuck out the window. It seems to be doing its job, though quite noisy at the moment.

Any tips, experiences, operational know-how appreciated.

N.

 

[Loru]

If it's internal unit, don't mount it above delicate non water resistant objects.

 

[tl8]

So in general, portables are terrible.

That said, the biggest tip is make sure that it is turned on. Heat waves kill a number of elderly people in Australia and it is not unknown for them to not turn it on because of cost.

 

[Notebook]

Thanks Loru.

Just reading the manual, and it does have a water-tank level indicator, and a cut-out. So, should be ok.
Its sitting in the front-room, next to the telly, making a racket. Mother not impressed, tough, its doing a grand job. Expecting polar-bears now.

N.

 

[Evil_Onyx]

It is extremely important you get your mother drinking lots of water (2+ liters a day) in this weather, older people generally don't drink anywhere near the required daily in take, and older people find it harder to regulate there own temperature.

I'm currently caring for my 92 (almost 93) year old Grandfather. and he is way more active than me at this temperature. And its 66% humidity and 28c and overcast out side at the moment.

 

[Donamy]

A ductless Mitsubishi is whisper quit and it heats in the winter.

 

[RisingFury]

I can't see from the pictures how it deals with water, but when you leave it on for hours in hot, humid air, it'll produce many liters of water. If the tank overflows, the water might spill. I had that happen to me when I fell asleep next to it running and I woke up with the parquet floor flooded. Oops...
Also keep in mind that water and electricity generally don't mix well, so make sure the power cable or extension cable don't short in case the unit floods.

As far as noise goes, one strategy is just to run it at full power for a while for the room to cool down, then reduce its power to maintain the temperature and of course minimize venting cool air. Biggest venting problem is with the duct that goes out of the window. Try to minimize losses there. If the window has those plastic shutters that roll down, roll them down to hold the duct in place. If not, try to insulate the open window with towels. Secure them so the wind doesn't blow them away.

The air duct that removes warm air is usually thin and plastic and it radiates some heat back into the room. Insulate it as best you can with towels or other fabric. The duct on our unit also sometimes jumped out of the exit hole for the warm air or got dislodged from the window, spewing hot air back into the room. Check on the unit occasionally to make sure that doesn't happen.

 

[Notebook]

It is extremely important you get your mother drinking lots of water (2+ liters a day) in this weather, older people generally don't drink anywhere near the required daily in take, and older people find it harder to regulate there own temperature.

I'm currently caring for my 92 (almost 93) year old Grandfather. and he is way more active than me at this temperature. And its 66% humidity and 28c and overcast out side at the moment.

Yes, that's a regular refrain from Carers and District Nurses. Found a brand she likes(Volvic, Hint of Summer Fruits!). Very difficult to get her to drink, and you just feel like a bully if you go on.

N.

 

[RisingFury]

One more thing I should add: After a few years of use, you'll see a decrease in performance. The working gas inside the unit slowly leaks out and the unit will need to be serviced.

 

[Thunder Chicken]

Check and empty the condensate tank frequently. They fill up faster than you think. Makes you feel like Uncle Owen the Moisture Farmer.

 

[C3PO]

I'm a bit confused when it comes to the subject of air conditioning.

When I studied the subject in engineering college air conditioning meant conditioning the air, not just cooling it. In fact the most important factor is the humidity. If you cool the air more than a few degrees below the outside temperature, it can be as unhealthy as the heat.

The trick is to lower the humidity enough to make it feel comfortable. There's obviously a limit to how hot you can safely be for prolonged periods, but the ideal delta is between 5-10° kelvin.

However I've never seen an AC that isn't just a cooler. It will remove some of the excess "rusty hydrogen" :shifty:, but personally I find it very uncomfortable to suddenly walk into a cold 100% humid air stream on a hot day.

The obvious solution would be to place a part of the condenser after the evaporator, but that will add complexity/cost. Especially if it has to be regulated.

 

[Notebook]

I've got a "home-weather" Oregon Scientific table-top thing. Its showing 23.2 degrees and 45% humidity at the mo.
Its dropped the room temperature about 3 degrees during the hottest part of the day today. Not bad for a room I cant seal, certainly makes it more pleasant.

In North UK, we shouldn't need this equipment, its not usual. But, if the circumstances require it...

N.

 

[Donamy]

You can get a condensate pump, that will pump the water outside, so you don't have to remember to empty it.

 

[dbeachy1]

I'm a bit confused when it comes to the subject of air conditioning.

When I studied the subject in engineering college air conditioning meant conditioning the air, not just cooling it. In fact the most important factor is the humidity. If you cool the air more than a few degrees below the outside temperature, it can be as unhealthy as the heat.

The trick is to lower the humidity enough to make it feel comfortable. There's obviously a limit to how hot you can safely be for prolonged periods, but the ideal delta is between 5-10° kelvin.

However I've never seen an AC that isn't just a cooler. It will remove some of the excess "rusty hydrogen" :shifty:, but personally I find it very uncomfortable to suddenly walk into a cold 100% humid air stream on a hot day.

Well, blowing the warm, humid air across cold metal coils will automatically also lower its humidity, because the cold coils cause the water vapor in the air to condense and then run to a drain, so the result is cooler and drier air (i.e., air with a lower dew point, and a lower dew point == more comfortable air). This page explains it:

...as your air conditioner cools the air that’s passing over the evaporator coil, the excess moisture in the air condenses, much like how water condenses on the outside surfaces of a cold glass. The condensed water vapor comes together, creating drops that soon are too heavy to remain suspended in the cool air. They drop into a pan below the coil, and run out through a drain.

The coils in an air conditioner (when it's running, of course) are quite cold, and so both cool and dehumidify the air. :tiphat:

 

[Linguofreak]

I miss living somewhere that AC is not required. I grew up in Denver, where there was enough of a temperature dip at night that running a fan in a window at night would chill the house and keep it cool for the next day. In Dallas, the heat and humidity are bad enough that an AC failure in summer means evacuating the house and finding someone to stay with until repairs have been made. Every house has built-in AC, and I honestly don't get how Texas managed to be inhabited before the invention of AC.

 

[Donamy]

AC doesn't cool the air per say. It extracts the heat from it and brings it somewhere else. :lol:

 

[C3PO]

Well, blowing the warm, humid air across cold metal coils will automatically also lower its humidity, because the cold coils cause the water vapor in the air to condense and then run to a drain, so the result is cooler and drier air (i.e., air with a lower dew point, and a lower dew point == more comfortable air). This page explains it:



The coils in an air conditioner (when it's running, of course) are quite cold, and so both cool and dehumidify the air. :tiphat:

Wrong, sorry. Assuming you are talking about relative humidity. And relative humidity is (along with wind speed) the most important factor when it comes to comfort.

When you chill air down below its dew-point, you will remove water. But air that's at its dew point has by definition a relative humidity of 100%. To lower the relative humidity you have to increase the temperature of the air.

A "real" AC lowers the temp to where dew point has the correct water mass/air mass (specific humidity), and then heats it up again to lower relative humidity.

 

[RisingFury]

I'm a bit confused when it comes to the subject of air conditioning.

When I studied the subject in engineering college air conditioning meant conditioning the air, not just cooling it. In fact the most important factor is the humidity. If you cool the air more than a few degrees below the outside temperature, it can be as unhealthy as the heat.

The trick is to lower the humidity enough to make it feel comfortable. There's obviously a limit to how hot you can safely be for prolonged periods, but the ideal delta is between 5-10° kelvin.

However I've never seen an AC that isn't just a cooler. It will remove some of the excess "rusty hydrogen" :shifty:, but personally I find it very uncomfortable to suddenly walk into a cold 100% humid air stream on a hot day.

The obvious solution would be to place a part of the condenser after the evaporator, but that will add complexity/cost. Especially if it has to be regulated.

The portable AC unit we used to have cooled the air from 27°C to 7°C when we first bought it. If you placed your hand on the cool air exhaust, it became uncomfortably cold really quickly.

While the 7°C air is near 100% relative humidity, it quickly mixes with the room's warm air. The overall mix then ends up at ~24°C, but relative humidity decreases.

 

[C3PO]

I think I've figured out what confused me. :facepalm:

In Scandinavia AC is almost always used in conjunction with ventilation. I'm guessing that in warmer climates buildings aren't insulated to the extent that the main problem is ventilation.
Most examples I've seen on-line use re-circulation, and that's the reason why they talk about dew point. It's the resulting mixture that has a lower relative humidity.

It has never come up because here it's recommended the air is completely replaced 1-4 times an hour, depending on type of building.

 

[Andy44]

Even more confusing, my house has a heat pump. Took me a while to figure out the difference between that and an "air conditioner".

About a month ago my heat pump's internal coils froze up due to low coolant and there was a gigantic block of frozen rusty hydrogen in there. Had to switch on the heat to melt off the ice and then got a tech to charge up the system and seal it, problem solved.