Air conditioning your house- advice needed! ?

EDManual · 13-02-2014, 09:50 AM

So I'm building a two storey 30 square house in geelong. I am wanting to go ducted evaporative but I only hear negative story's. . But I'm still keen.

So for about $5000 I'd get a ducted system to the top floor and apparently you leave ground floor Windows a bit open and the air comes down. The top floor is the warmest area obviously. Meant to be cheap to run.

Otherwise split system with 2 heads, one to both floors.

People say the evap only cools about 10 degrees from outside air and on humid days does nothing. Now we've had a lots of 40-45s this summer so chilling that down 10 isn't very good. Would be better closing curtains and blind in the morning and by the end of the day if it hit 30-35 inside with no evap ac. Otherwise with a split system the temp would stay at 25 easy I'd suppose and you can keep recycling indoor air. But costs lots to run.

I'm thinking of going double glazed Windows as well which in thinking about it would have no benefit at all in summer with evap ac.

Any thoughts?

poppa smurf · 13-02-2014, 09:59 AM

swampys been useless here the last 15 days, 45 plus and high humidity, today it is like the Louisiana bayou's.

if you can afford it go reverse cycle ducted right through the house, swampy will do maybe 80% of the time but the other 20% is hell.

naddis01 · 13-02-2014, 10:01 AM

Are you sure you can do a 30sq house with 2 split systems?

We built a few years ago and put ducted reverse cycle in and also a 3kw solar system. That way we can run it as much as we want and not have to worry about the bill. Well for the next few years anyway until we lose our 60c rebate. 45 degree days? What 45 degree days?

We went with Actron Air. Australian designed and made. From memory they were a fraction cheaper than the Fujitsu. We had one warranty claim, although I think it was more an installation issue, which fixed without any hassle. Fantastic product and service so far.

Swampys are good, until they're not and then they suck.

xxx000 · 13-02-2014, 10:01 AM

Go ducted upstairs. We've got a 2 storey house and a ducted inverter system up stairs.
It's great for cooling and heating but we now use a gas fireplace downstairs for heating both levels

Don't buy Fujitsu, they last just out of warranty and break down. Lots on whirlpool about them
Go Hitachi or Daikin.

EDManual · 13-02-2014, 10:11 AM

How does evaporative go on a 40-45 degree day with low humidity? Really around my area geelong, it's very rare to have humidity above 35 degrees.

BENT_8 · 13-02-2014, 10:20 AM

We have a new ducted evap. been 40+ here in Adelaide for almost 2 weeks, no dramas at all.

People who complain about evap systems don't know how to use them properly.

$5k seems a little steep, our 6 outlet only cost 3.5k.

As has been said, a split wont cool a whole level, well not without working hard.
We have a split in the family room and it rarely gets used because it only cools 1 room really, and it is a reasonable sized unit.

Pinkbits · 13-02-2014, 10:42 AM

Double glazed windows are a good start.
You need to have good insulation in the walls as well.
I'm talking batts, not just the compulsory sisalation.

We have had both types, and with insulation that I installed when the house was being built as I mentioned above, our indoor temp with the evap unit could be up to 20+ degrees cooler than outside.
We currently have a 7.1kw Panasonic split system in the new house (30 yo) with good insulation, double glazed windows & block out blinds.
It is set on 23 deg with low fan & it keeps the main areas very comfortable in all temperature extremes.

BENT_8 · 13-02-2014, 10:48 AM

Quote:

Originally Posted by EDManual

How does evaporative go on a 40-45 degree day with low humidity? Really around my area geelong, it's very rare to have humidity above 35 degrees.

The humidity thing is a myth, it is all about how you use the system.

Look at how they work, water floods a pad and a fan draws outside air through it.
wether humidity is high or not the air is drawn through water so it will contain moisture regardless of the outside conditions.
The key to making them work right is opening the correct windows and setting the fan on the lowest setting you need.

Heres an example.

lets say its a 40* day with hot northerly winds.
You put your evap. on in the morning and open all windows.
Whilst the rooms with southern/eastern/western facing windows will cool due to the systems process of introducing fresh air into the room, passing through and exiting the window, any open windows on the northern side will allow the hot outside air in as it will over ride the pressure created by the system. The stronger the winds, the worse it is.
This negates the evap. process and creates inside humidity.

Now, you could turn the fan speed up to create a higher pressure void inside and prevent the hot air from entering, but then you are drawing hot air through the pads quicker which lessens its exposure to the cool water and therefore less effective.
This is where many get it wrong.

The key is to close any windows which are facing the direction that the wind is coming from.
Open the windows on the opposite side a bit extra to compensate.
Put the system on early in the day and leave it on the lowest fan setting to get the job done.

Something to remember with splits is that they only recycle the stale air inside and can get quite smelly in some cases.

When I installed my first ducted system I was sceptical too, but after using them for 14yrs now I wouldn't go back to a refrigerated unit.

adumb · 13-02-2014, 10:50 AM

30 sq single storey with just evap. Like others have said you need to windows for it to really work properly. On the really hot days just past around 40 outside it was about 25-27 inside, which was very comfortable, I dont like to feel like I am sitting in a fridge.

mik · 13-02-2014, 11:21 AM

I'm a big fan of refrigeration, yes it costs, but it actually cools without that clammy feeling, Edit, i like feeling like i'm in a fridge, and you can always turn the thermostat down..

MAD · 13-02-2014, 11:22 AM

I reckon evap for general use, and a small split in the living area for the extreme days.
You get the bonus of circulating fresh air through the house, instead of closing everything up as with refrigerated.

Some people don't know that you need to open doors/windows for evap to work properly.

poppa smurf · 13-02-2014, 12:03 PM

take a squizz here....

http://www.braemar.com.au/images/sto...912_f_webn.pdf ...

pay particular attention to the testing regime and conditions......the manufacturer makes particular reference to high humidity.

interesting to note it can be "multi zoned".......if you do not have high humidity then it should be fine.

we have the RPA series which is light industrial on the house and I have heavy industrial on the shed

both units serviced monthly by air-con specialists.

I am about to update my air-con on the house to reverse cycle ducted because of this latest heat wave, night time has not been pleasant, but if you don't get this rubbish in geelong then a swampy will be fine.

go as big as you can, larger units work better than smaller units, if you can go to a house that has a swampy on a mongrel day and make up your own mind.

chevypower · 13-02-2014, 12:04 PM

Refrigerative and double-glazed windows with low-e. If you are looking at getting windows, I'd love to send some business to my dad who has his window business in Hallam, if you wouldn't mind getting a quote from him. Ed Stelling at EcoClassic Windows. www.ecoclassic.com.au.

MarkAW · 13-02-2014, 03:31 PM

I don't know if the ducted systems are simply reverse cycle or you can get them as an inverter system. Always try for the inverter.

My house in Sydney's west originally came with a small window box rev cycle AC which cooled the lounge room OK and a bit of the kitchen. When we added a new room (lounge room) at the front, we fitted a 7kw inverter which now cools most of the house. The big bonus is that its consuming the same amount of energy to cool 4 rooms as the window box did for 1 1/2 rooms. It doesn't cool the back bedrooms without freezing the rest of the house so we just installed a small inverter just for the bedrooms - on hot nights its a must, add in the ceiling fans to mix the air and its goodbye sleepless nights.

damoose · 13-02-2014, 03:35 PM

I think it comes down to personal preference having a house with both systems the evap suits me much better as I hate being locked in a box and if the wife ever burns something in the oven you can reverse the evap and suck all the smell and stuff out.

zilo · 13-02-2014, 05:26 PM

Get FOUR split systems.

Then get a 5kw solar panel array to run them for free all day long.

That's the best setup.

Evap cooling is last century stuff.

XP6 · 13-02-2014, 05:54 PM

4 splits... 5kw array I dont think so you'd need a 10kw+ system to even come close to the power consumed by 4 split systems on at the same time!

I think you really need to design the house to your climate 1st then run type both systems(unless in the tropics), use refidge during the humid condition days and run the evap at night in bedrooms for sleeping... best of both worlds.
This is what were doing right now with our new house, refridge in the greatroom(120m2)and evap in the other half of the house. UVPC double glazing through out with a passive design heavily insulated(skillion roof with a vaulted ceiling and celestial windows facing north, polished concrete as a thermal mass floor in the great room, its nearly half the house in 1 room...)

BENT_8 · 13-02-2014, 06:53 PM

Quote:

Originally Posted by XP6

4 splits... 5kw array I dont think so you'd need a 10kw+ system to even come close to the power consumed by 4 split systems on at the same time!

I think you really need to design the house to your climate 1st then run type both systems(unless in the tropics), use refidge during the humid condition days and run the evap at night in bedrooms for sleeping... best of both worlds.
This is what were doing right now with our new house, refridge in the greatroom(120m2)and evap in the other half of the house. UVPC double glazing through out with a passive design heavily insulated(skillion roof with a vaulted ceiling and celestial windows facing north, polished concrete as a thermal mass floor in the great room, its nearly half the house in 1 room...)

This is a good medium.

For arguments sake, lets assume that on a humid day your evap wont work as efficiently.
Being honest, how many days of the year have humidity that will affect the evap. process?
A handful?
Is it worth forking out thousands of extra dollars for a full house refrigerated setup to cover a handful of days, not to mention the extra running costs.

It would be like buying a 4wd to go off road 5 days a year when a cheaper falcon would suffice for the other 360 days.

Put the evap on the roof and a split in your main living area if necessary, best of both worlds.

**MercurySilver** · 13-02-2014, 08:07 PM

40 degrees plus here last fort ighf and our evap ducted was OK. Might've been 27 in the house but sitting under vdnf with the fan on 12 who h is flat out was lovely.
WD also have a decent dplitty in the media room..
Youcsn get big splitties now that hook up to ceiling cassette outlets.
Go refrigerated if you want ice cold and a thousand dollar electricity bill

BigCav · 13-02-2014, 08:16 PM

my swampy got me threw summer here in wallan (north of melb) quite comfortably, yes sometimes the air is a big muggy but its not too bad at all, i do prefer the feeling of refrigeratives but it worked out cheaper etc for me and im very happy with it

neptune blue · 13-02-2014, 08:39 PM

I have 2 evaporate units in my house which is a single story that has 38 sq of living
They work great
We usually only run one but when it gets around 38 degrees we run 2
As it has been explained, to make it work properly you need to ensure good airflow lots of open windows
The only time it doesn't work well is in high humidity

In low humidity or dry heat the water evaporates cooling the air so its fresh / cool not cold
The airflow passing through the house makes it feel cooler

In high humidity the air already contains moisture so by adding more mosture to it the water doesn't evaporate as much
Consequently surfaces such as tiles get condensation

This is the second house I've had evaporative cooling in and I can count on one hand the times we had humidity that affected its performance

If I were you I would run the evap upstairs and a split system down stairs
Our neighbours did this as their evap unit couldn't cope on really hot days

Also evap is way cheaper to run than any refrigerated unit , this includes ones with inverters
you can direct the airflow with evap cooling e.g if you want to cool a single room you only open the window in that room and all the air will flow there
You can't do that with refrigerated

Kids run in and out of the house all day, no big deal with evap cooling as it relies on open windows & doors to function

Got ours going at the moment and I'm very comfy - and it's humid at the moment

290v · 13-02-2014, 08:45 PM

make sure when building have 3 phase power put on most Reverse cycles run on this

**redxm** · 13-02-2014, 09:00 PM

Got a new roof last year from hail. We paid extra and got blanket sarking put in. That and the insulation in the ceiling already, easy 5 deg, maybe more cooler inside. Also scored a new swampy at the same time.
House is very comfortable now.
Its been 36 to 45 here since xmas.
Roof got bombed again and this time the split aircon is getting replaced. Daiken instead of some chinese junk thats in now.
If you can stop the heat getting into the house you are streets ahead. Roof ventilation and wall/roof insulation is a must.

zilo · 13-02-2014, 09:48 PM

Quote:

Originally Posted by XP6

4 splits... 5kw array I dont think so you'd need a 10kw+ system to even come close to the power consumed by 4 split systems on at the same time!

..)

nah...5kw will do fine, they run on a duty cycle that's low when up to temperature, whereas the panels still pump out when the compressor(s) are at set temp.

Bit like having a fridge rated at 1kw, but it only comes on when you open the door....so effective duty cycle is about 5%

Aircons run about 50% on a stinker day at say....21-25 degrees

BENT_8 · 13-02-2014, 10:03 PM

Well its 9.30 here in Adelaide, still around 24*.
Its been ****ing down all day with temperature around 30*

Humidity was high 90's.

My 'swampy' has been lovely all day.

zilo · 13-02-2014, 10:37 PM

Quote:

Originally Posted by BENT_8

Well its 9.30 here in Adelaide, still around 24*.
Its been ****ing down all day with temperature around 30*

Humidity was high 90's.

My 'swampy' has been lovely all day.

Evaps will give you a smaller cooling differential than a refrig system.

When it's 45 here in Melbourne, the only system that can cool to 21 is a refrigerated system.

An evap will get it down from 45 to about 35-36...but...nah

That's too bloody hot for me when trying to sleep, I need 21-22

Maybe the OP can evap the house and have a small split system in the main bedroom etc?

BENT_8 · 13-02-2014, 11:18 PM

Quote:

Originally Posted by zilo

Evaps will give you a smaller cooling differential than a refrig system.

When it's 45 here in Melbourne, the only system that can cool to 21 is a refrigerated system.

An evap will get it down from 45 to about 35-36...but...nah

That's too bloody hot for me when trying to sleep, I need 21-22

Maybe the OP can evap the house and have a small split system in the main bedroom etc?

To be fair, an evaps job is not to lower the ambient air temp(although it does), it works the same way your bodies own temp regulator works by providing constant cool air flow over the body.
When you get hot your body produces sweat which inturn is cooled by air flow and the process of evaporation.
It doesn't require that the ambient temp drops for this to happen, its about the sweat(water) and breeze(fan forced air) combining.

The evap works the same way, although it doesn't require that you sweat for it to work as the unit supplies the moisture for you.

mik · 14-02-2014, 12:19 AM

so what about upkeep on evaps, how much does that cost annually ??

poppa smurf · 14-02-2014, 10:58 AM

Quote:

Originally Posted by mik

so what about upkeep on evaps, how much does that cost annually ??

depends on age of unit and what pads are installed also whether it has an automated bleed system.

I pay around $50 per month for two units to be drained and cleaned, but I'm a business so my units have to be correct health wise, if you are nimble you can do it yourself.

Road_Warrior · 14-02-2014, 11:19 AM

Quote:

Originally Posted by EDManual

How does evaporative go on a 40-45 degree day with low humidity? Really around my area geelong, it's very rare to have humidity above 35 degrees.

We've got ducted evap in our house and there have been some stinkers in Perth lately and the air con has coped fine. It cools the house to a comfortable level and doesn't leave you feeling like you're sitting in a fridge.

Unless, of course, that is what you want, in which case go for a refrig system.