Browse Forums Heating, Cooling & Insulation 1 Apr 15, 2014 3:53 pm Hi there - my salesman for my build has suggested that I put in an evaporative airconditioner rather than a reverse cycle to save on running costs. He says I should consider putting in a split system into the main living area and bedroom (mine and child's) if needed. The cost for the reverse cycle will be around $10,000.00 and the evaporative around $5,000.00 but putting in 2 to 3 split systems could cost up to $6,000.00 more, so the cost of installing both systems is about the same. My question is, would it save a lot of money on running costs by using an evaporative and split systems versus the reverse cycle anyway? To give you some background - I live in Perth, the summers are horrendous particularly when it's humid and I adore airconditioning. The nights are okay with using evaporative but during the hot summer days the heat is unbearable. So, in short, I definitely want airconditioning but am not sure whether the savings of the running costs is worth it. Any advice would be most appreciated! Thanks! Daisy's Providence Wellard build with Domain Homes - viewtopic.php?f=31&t=72176 Re: Airconditioning - running costs - Reverse Cycle or Spli 2Apr 15, 2014 4:27 pm Honestly, if he is suggesting to put in reverse cycle splits, it's because the evap wont cut it. And in Perth, it probably wont. I would go the Ducted R/C. We are in Adelaide and the evap we had in a rental (less than 2 years old) didnt do much of anything past 35 degrees, when you really actually need it! We had a split system in the lounge area and used to have to run it to get any relief during heatwaves and over 35 degrees. My aunty had Evap in Melbourne and loved it, but the home was an older stone cottage with 1.5 meter verandahs all around and plenty of shading. Another question to ask yourself is - do you like doors and windows being open when the air con is running? (you need to with evap or it wont work effectively) or Do you prefer to close up windows and doors at night/during the day? The other thing with Evap is you cant just come home from shopping/work etc, put the a/c on and cool the house down, you need to have it running for a fair while, whereas R/C you can do an instant cool down. People will swear by Evap being fresh and breezy and ducted r/c being stuffy and stale, but I dont agree. We have a ducted inverter r/c system at our current rental and it is delightful... great on power too and it works. Thread: viewtopic.php?f=31&t=66299 Slab: 16/6/14 Frame: 4/7/14 Roof: 22/7/14 Lock Up: 20/8/14 Fixing: 26/8/14 PCI: 9/10/14 Handover: 20/10/14 Re: Airconditioning - running costs - Reverse Cycle or Spli 3Apr 15, 2014 5:28 pm If you like air conditioned comfort then evaporative won't cut it for you. Yes evaporative has lower running cost as it is only running a fan and small water pump whilst a ducted system is running two fans (inside and outside) and compressor, which is the high power consumer of the system. If you want lower running costs then the trick is to design your house well with regards to solar orientation, have appropriate insulation and zone your system adequately for your lifestyle. Re: Airconditioning - running costs - Reverse Cycle or Spli 4Apr 15, 2014 6:11 pm What Dukecaddy says is correct, but if you're dealing with a salesman I assume that means it's a project builder; and you may not have that many options with respect to appropriate solar orientation & design. How big is this house? I ask because two split systems PLUS an evaporative cooler sounds like you're trying to cool a 4+ bedroom house, but $10k sounds very cheap for a system to do a 4+ bedroom house ... a $10k ducted system probably would not cope, and would not be likely to be able to operate multiple zones efficiently. In terms of running cost, you can get smart ducted aircon systems that are able to reduce power consumption depending on how many zones they're cooling or heating; but those are fairly expensive. The traditional ducted aircon uses almost as much power when it's cooling just one zone as when it's cooling all zones, and for this reason split systems do tend to use less juice; because you only use the power in the area you've got the split-system turned on. and if you think about it, you don't use all of the house at once; at night it's bedrooms, during the day it's usually NOT bedrooms. We've gambled a little bit on getting an ActronAir ESP-Ultima ducted system with 7 zones & 7 separate sensors, and where each zone can be turned on/off individually; because the sales spiel says that it can downsize the power it uses to match what's needed; but I can't say if that's going to be as energy efficient as 4-5 separate split systems (although it's probably cheaper to install - if not to buy). Re: Airconditioning - running costs - Reverse Cycle or Spli 5Apr 15, 2014 6:47 pm Ducted zoning is generally only controlling the airflow into the zone. Temperature is controlled by modulating a damper in the ductwork to reduce the airflow for part load conditions or shut-off the airflow for zones turned off. However the unit usually has a central return air grille, so whilst you may be cooling your bedrooms the unit is actually taking the air from the warmer/hotter corridor (or wherever the return grille is located). Hence you're not seeing the full benefit of cooling one zone only as you would get from a single wall split. The best you will get is that the fan in the ducted unit is running at low speed and hence only cooling the minimum amount of air possible. Re: Airconditioning - running costs - Reverse Cycle or Spli 6Apr 15, 2014 7:30 pm If you go for real air conditioning, i.e. refrigerated (which also heat as well), then go for multiple split systems. You will end up with far more control over it, than a ducted system ever will, as they suck the air in from a central location in the house, so even though you have zones, the air has to go in to a central area to go through the system. Multiple split systems allow you to only operate a lower powered system in one or more locations. Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . Re: Airconditioning - running costs - Reverse Cycle or Spli 7Apr 15, 2014 8:37 pm [quote="bpratt"]If you go for real air conditioning, i.e. refrigerated (which also heat as well), then go for multiple split systems /quote]
You will need to consider if you have ample space for the individual outdoor condenser or consider a multi-splits running off a single outdoor condenser and it will cost more. Suggest have look at whirlpool forums as the different options have been discussed. I have a ducted r/c and with two kids under 4. It was able to cool the house down to the temp I want during the heatwave we had in SA. Re: Airconditioning - running costs - Reverse Cycle or Spli 8Apr 15, 2014 8:47 pm I would go to an air con shop and ask them. It may be that your salesperson gets a bonus for evap air cons? I think for re-sale, a refrigerated r/c ducted system would be more desirable to buyers. I'm from Perth too and I thought the general consensus here was evap systems aren't that great. Re: Airconditioning - running costs - Reverse Cycle or Spli 9Apr 15, 2014 8:48 pm Also, another way to combat the running costs is to spend that other $5k on solar panels (which would also add value to your house). Re: Airconditioning - running costs - Reverse Cycle or Spli 10Apr 15, 2014 9:37 pm I had very similar question just recently. My house is 4 bedrooms plus study and, being in Adelaide, I don't imaging living without cooling or heating (nights can be pretty chilly here). To install evaporative cooling plus gas heating will cost the same as r/c ducted system. Running cost of the evaporative is cheaper but you also have to consider a cost of water as the new units dispose 18 liters of water every 4 hours automatically (old units did not do it the same way), it is over 100 liters of water extra per day. As deluxes mentioned before, you have to run evaporative system for a few hours to cool the house down, on some hot days we have to run it non stop day and night few days in a row otherwise it will not do the job. R/C ducted system with 6 zones will cost me around $8,200 to install and, with solar panel I am planing to add to my house, will be more efficient to run than two separate systems for heating and cooling. First house - Statesman Greenock (modified) https://forum.homeone.com.au/viewtopic.php?f=31&t=66876 Second house - Fairmont Grand Design (modified) https://forum.homeone.com.au/viewtopic.php?f=31&t=100789 Re: Airconditioning - running costs - Reverse Cycle or Spli 11Apr 17, 2014 11:55 am You may want to also check the power consumption of the actual ducted reverse cycle unit you're looking at. We were not able to fit the inverter model unit into our ceiling space and were limited to the non-inverter. It was also a large unit that was required for the house, something like 23kw or 25kw. I had some assistance to work out tyical power usage and was 'blown away' by the costs of running it. Over $2 an hour at peak load. Long story short, we ended up going with the evaporative and double glazed windows on the house we;re building. We may install splits in the bedrooms if we need it. Our summers can reach 45 degrees in North West Victoria! We had Evap and splits in the bedrooms in our last house and rarely used the splits. Collectively, probably about 2 weeks in a year, just at night. Also, the house we're living in while building has a non inverter ducted reverse cycle system (i think its about 16kw). During summer, we had it set anywhere between 23 and 26 degrees and would leave it on all day so the house didnt get a chance to warm up. It was great while the unit was running but once it would reach temperature, it would shut off and it would get quite warm and stuffy quickly before it would kick in again and start blowing cool air. I found this quite annoying. We also had a $980 power bill for the quarter and there are solar panels on the roof. Not sure how big the sysem is but there are 12 panels up there. To compare, when we were in our old house the previous summer (with evap cooler), our quarterly power bills wouldnt exceed $450. Re: Airconditioning - running costs - Reverse Cycle or Spli 12Apr 17, 2014 12:12 pm Evaporative air conditioners work excellent in dry, arid, hot climates and extremely poor in humid climates. I would never recommend installing one in a humid climate. Re: Airconditioning - running costs - Reverse Cycle or Spli 13Apr 18, 2014 10:26 am We have very dry climate in Adelaide but evaporative still not working well when the temperature riches over +35 especially if it is stays that way for a few days First house - Statesman Greenock (modified) https://forum.homeone.com.au/viewtopic.php?f=31&t=66876 Second house - Fairmont Grand Design (modified) https://forum.homeone.com.au/viewtopic.php?f=31&t=100789 Re: Airconditioning - running costs - Reverse Cycle or Spli 14Jul 02, 2014 11:31 pm Hi Daisyinthedesert I too live in Perth and have an evaporative system as well as 4 split systems (Living area, games room, Master bedroom and Infants room. I would not have it any other way. We use the evap 95% of the time, but on humid days, when the evap doesn't work then we use the split sys. Also when the nights are warm then the evap is perfect as it always works at night and running costs are so low. Yes, the cost is pretty much the same as a good quality ducted reverse cycle, but the running cost would be huge compared to the way we run it and we never give it a second thought to turn it on (as a lot of people with ducted reverse cycle do, due to running cost). hope this helps. Re: Airconditioning - running costs - Reverse Cycle or Spli 15Jul 03, 2014 8:41 am Your location will make a evap cooler work or not work as well. If you are in a higher humidity area, a evap cooler will not work well enough as you are only adding to the humidity, and therefore a RC A/C will be what you require. A option that hasn't really been mentioned is ceiling fans, as they are even cheaper than evap coolers are to run through the night. A/C or evap coolers will work 'better' with ceiling fans in the room, than without them. With A/C and ceiling fans, you chill the room going to bed, then turn off the a/c and just use the fan for the rest of the night. One thing that is really worthwhile doing to your bedrooms at build time is not just ceiling insualtion, but in wall insulation. Keep your 'sleeping capsule' insulated, and you won't use your evap cooler or a/c as much in the first place. Oh, and BTW, this thread should have gone in to the Heating, Cooling, and Insulation sub forum .... I only just noticed this thread this morning. Owner Building at Jimboomba Woods in Logan City Qld. Blog : http://bandlnewhomebuild.blogspot.com H1 thread : viewtopic.php?f=38&t=68283 . 2 6108 Hi all I am looking to run a water line under my concrete footpath which is directly next to my home, was seeing if this is possible without cutting the entire section… 0 20034 I am not sure whether Perth has its own way of doing things in regards to this. Most of Perth has class A (sandy soil), except for some areas near rivers or hills. 2 12980 |