Domestic Air Con

[reflexboy]

Morning all
In the summer my bedroom is virtually unbearable. I get the sun full on in the morning, and if it has been a sunny day, the nights are unbearable. I have a portable AC unit which I have vented through the wall but 1-It doesn't lower the room temp enough(about 2-3 degrees in 3 hours) and 2-It's so noisy I cannot sleep with it on. I usually turn it on 3 hours before bed!!
My bedroom is approx 3x4m
I was thinking of one of these whisper quiet split units, so as the compressor is on an external wall. Many units like this are now sold DIY, with pre-filled gas, however my concern is are these as good as the split units that are professionally installed initially with no gas, and what happens to the air space with no gas in it, in the connecting pipes on these DIY units? I was thinking something like this:

12000 BTU WALL SPLIT CONDITIONING UNIT HEAT PUMP SYSTEM | eBay

or this

Air Conditioning 18000 BTU Split System TOSHIBA DIY | eBay

 

[GordonTarling]

I wouldn't worry about airspace in the pipes - they have quick couplers on the pipes and I guess all the pipes are filled, so very little air in there anyway. I'd be more worried about statements like this - "Heating output of 5.8KW for only 1800W of electrical energy used!" Now, what have they discovered that permits more than 100% efficiency?

 

[Derek Mc]

I would consider both a ceiling cassette type (providing you have beam clearance for the small 600 x 600 unit with external condenser as wall mounted as ceiling mounted is far more efficient.

As for costs it could be approx £3,500 to supply install and gas up for a professional system offering warranty (as this is what I offer clients on my fit-out's) or a semi d.i.y white van man system at about £2,500.
or, a DIY B&Q job for about a grand all told.

 

[st13phil]

In the summer my bedroom is virtually unbearable. I get the sun full on in the morning, and if it has been a sunny day, the nights are unbearable.

Our bedroom is south facing too, so I totally understand your problem. We bit the bullet about 5 years ago and had air-con installed and the improvement it's made to our sleep and therefore or lives during the summer months was well worth the expenditure. My wife mainly works from home and we have a home office set up in the other bedroom on the same side of the house which used to get similarly unbearable temperature wise during the summer, so we decided on installing a multi-split system.

Based on our experience (similar size room to you), a 9,000 BTU/Hr capacity will be more than adequate for your bedroom. With our bedroom at an ambient 30c, from switch-on it takes under an hour to get the temperature down to 18-20c and it will then maintain that temperature on a low setting. We had units from the LG Artcool range installed as they look a bit less industrial than most other units. They're also quiet when in the "night time" mode and don't disturb our sleep in any way. LG units seem to have a bit of a mixed reputation, but ours have been faultless so I have no complaints, however Daikin units generally come highly recommended and have some very quiet indoor units too.

You'll need to consider where you locate the outdoor unit. Remember that they do make a noise and create heat so you need to take into account neighbouring properties. If it's installed at ground level (generally a good idea because of their weight) pipe runs can end up being quite long, and you'll need to get the electrics wired and inspected. Personally, I'd look for an installer and get them to size, recommend, and install a system even if you're a competent DIY'er.

 

[st13phil]

I would consider both a ceiling cassette type

Good advice. Cassette type would have been my preference, but the ceiling and joist layouts in our house didn't lend themselves to it

I concur with your price estimates.

 

[Apial]

I wouldn't worry about airspace in the pipes - they have quick couplers on the pipes and I guess all the pipes are filled, so very little air in there anyway. I'd be more worried about statements like this - "Heating output of 5.8KW for only 1800W of electrical energy used!" Now, what have they discovered that permits more than 100% efficiency?

It is because it is a heat pump. The missing energy is extracted from the air in this case, leaving it colder. This is not as efficient as a ground source heat pump, but still pretty good.