Browse Forums Building A New House 1 Jul 25, 2021 4:54 pm Hi all, I need help based on your experience with ducted aircon correct size. We will be building our new house where the internal group floor area is 120 square meters and 120 square meters for the first floor. We are located in Orange NSW (Climate zone 7). Our ceiling insulation is R6.0 plus 60mm anticon blanket (R value 1.3), external walls R2.7 and R4.1 for floor joist of between ground floor. Internal wall for ground floor R2.7 and first floor internal walls have soundscreen R2.5. All windows normal glass double glazed. One of the guys from this website help us with energy modelling for window sizing and insulation level. Nathers energy rating (not official) around 7. We have asked a local aircon installer a quotation for reverse ducted aircon. Calculated heating capacity of 19.04kW and cooling capacity of 17.48kW. House electrical wiring is single phase as per inclusion. Option 1: Single phase Daikin premium inverter 16kW Indoor unit: FDYA160AV1 Outdoor unit: RZA160CV1 Rated capacity: Cooling =16kW, Heating = 18.0kW Capacity range: Cooling = 7.3-17.0 kw, heating =7.3-20.0kW Option 2: Three phase Daikin premium inverter 18Kw (heating focus option) Indoor unit: FDYQ180LCV1 Outdoor unit: RZYQ7TAY1 Rated capacity: cooling=18.0kw, heating=20kw Capacity range: cooling=10.8-20.0kw, heating= 12.0-22.4kW. Note: There will be additional cost from the builder to have a 3 phase electrical wiring, no actual figure yet) Option 1 is a little bit under the calculated heating/cooling requirements and option 2 is a little bit over. I’m leaning toward option 1 as it’s a cheaper. But my question is will that be enough for the requirements. Our assumed daytime area is 120sq meters. That’s the ground floor internal area? Hope to hear all of your valuable input and as well as sharing your experience. Re: Which ducted aircon size? Daikin 16kW or 18kW? 2Jul 25, 2021 10:35 pm I think you will be just fine with option 1. We have Daikin 3 phase Standard Inverter FDYQN200LBV1 / RZQ200LY1 - 20.0kw cool / 22.4.0kw heat, here Canberra; and we have extreme temperature variations compared to Orange. I have tiled roof, 6.0R ceiling insulation, 2.5 wall insulation and uPVC double grazed windows with northerly exposed design. We were calculated to go for Deakin max capacity (24kW) premium system, but we have gambled to go with 20kW system. We were right on the money, after two years, we run the A/C only for few hours during extreme days of the worst months - and the A/C never really struggled to cool or heat. The high R value of the house (7.2) definitely helps. For Orange, you have done excellent insulation for your home, and with your assumption that you will only need half of the living area to be air conditioned at a given time is practically correct - combining both these aspect (also assuming you have decent solar passive design) you can safely go for the lower capacity AC unit in my humble option. The Deakin Premium in place of Standard won't save you much on electricity based on the touted higher efficiency of the Premium system. The efficiency gain will be especially irrelevant if you are planning to go solar down the track. One thing we really regret now though, is not choosing the "MyAir" controlleroption the installer was offering under 2k. That would have been really good, as it has sperate ducting and real valve and sensors for individual rooms and living zone and each can be separately controlled and scheduled. The wall controller itself is a neat Samsung tablet (in oppose to the very outdated and functionally crippled Daikin wall controller). If you can I would strongly recommend to go for it, as retrofitting this option later on will cost you near 5k. With MyAir, you truly only need to switch A/C on where you are currently in; giving you (and others) convenience on your temperature level at the same time providing efficiency by completely cut-off other areas using motorised real duct valves. In the ducted offering (that we currently have) the main zone will always be on and you can only choose the other zones to be off or on- in practise this is not we always want. Also in regards to 3 phase, regardless of the A/C, note that when you later go with Solar this will allow your ability to export electricity to the grid, as most of the suppliers have a 5kW limit for single phase, if you have 3 phase you could export up to 30kW (in our case 10kW/h limit). Another thing to consider if you would require a 3 phase system when you have an electric car etc, but I am not an expert in this area. All the very best with your A/C choice ! Re: Which ducted aircon size? Daikin 16kW or 18kW? 4Jul 26, 2021 4:25 pm For such a size of a house 16kW should do the job. Just make sure your enough outlets to cover all areas. How much are they quoting you for each, and how many outlets? Re: Which ducted aircon size? Daikin 16kW or 18kW? 5Jul 27, 2021 9:51 am Ceddy_83 For such a size of a house 16kW should do the job. Just make sure your enough outlets to cover all areas. How much are they quoting you for each, and how many outlets? Option 1=$15900 Option 2=$17900 Is this a fair price? Re: Which ducted aircon size? Daikin 16kW or 18kW? 6Jul 27, 2021 12:03 pm Leona33 Option 1=$15900 Option 2=$17900 Is this a fair price? See my quote, June 2019, Orange prices may be different or it has raised up sharply now. Note, only the highlighted is the actual supply and install figure, rest is optional https://pasteboard.co/Kd2FoPR.png Re: Which ducted aircon size? Daikin 16kW or 18kW? 7Jul 28, 2021 2:14 pm Leona33 Ceddy_83 For such a size of a house 16kW should do the job. Just make sure your enough outlets to cover all areas. How much are they quoting you for each, and how many outlets? Option 1=$15900 Option 2=$17900 Is this a fair price? extremely fair.. normally 17K plus but depend on outlets, zones, controlers etc etc... Re: Which ducted aircon size? Daikin 16kW or 18kW? 8Jul 28, 2021 2:44 pm What is your house plan like? You can simply consider one smaller split bulk head unit for your ground level (e.g. 5kW) coupled with 2-3 ceiling fans (can be built into the kitchen bulk head) + 10 kW ducted aircon for upstairs with one duct to each bedroom and rumpus. Generally, you would use your split aircon during a day and then turn on your bedroom aircon closer to night time for few hours before going to bed to cool down the bedrooms. You will save a lot of space in your wardrobes which is generally eaten with ducts and the installation will be much cheaper due to minimum labour required. This approach will also result in substantial energy savings too. Keep in mind that even if you close some of your ducts, your aircon will still be running at close to the full power. Re: Which ducted aircon size? Daikin 16kW or 18kW? 9Jul 28, 2021 3:33 pm We have a 12 month old daikin premium 16.6kw 3 phase. I went premium so it can wind down further to lower power draw when it suits. I’ve found that even the premium doesn’t wind down enough and on lowest setting still uses plenty of power. While you can try running one room only, it needs a minimum amount of airflow so it will automatically open more zones. If doing again I would look at options for 2 smaller inverters (if even possible). Even though multiple split systems would enable more efficient use of power by running only the splits needed, I’d still go ducting as split systems all over the walls look rubbish, plus controlling the whole house HVAC with one control (can do remotely also via phone) is awesome. If you are going to be in the house for 5 years or more I’d strongly suggest 3 phase. Not only do you get the option to export more solar, but regardless of what Australia does, the rest of the world is well down the path of banning petrol powered cars and in future we’ll have no choice but to buy electric vehicles. The cost of upgrading to 3 phase now will be far less than trying to do it later. Re: Which ducted aircon size? Daikin 16kW or 18kW? 10Jul 28, 2021 4:34 pm supersleuth We have a 12 month old daikin premium 16.6kw 3 phase. I went premium so it can wind down further to lower power draw when it suits. I’ve found that even the premium doesn’t wind down enough and on lowest setting still uses plenty of power. While you can try running one room only, it needs a minimum amount of airflow so it will automatically open more zones. If doing again I would look at options for 2 smaller inverters (if even possible). Even though multiple split systems would enable more efficient use of power by running only the splits needed, I’d still go ducting as split systems all over the walls look rubbish, plus controlling the whole house HVAC with one control (can do remotely also via phone) is awesome. If you are going to be in the house for 5 years or more I’d strongly suggest 3 phase. Not only do you get the option to export more solar, but regardless of what Australia does, the rest of the world is well down the path of banning petrol powered cars and in future we’ll have no choice but to buy electric vehicles. The cost of upgrading to 3 phase now will be far less than trying to do it later. Couldn't agree more.. Re: Which ducted aircon size? Daikin 16kW or 18kW? 14Sep 15, 2021 5:20 pm Ceddy_83 Leona33 Wow! This is the best about online community! l learned a lot! Thank you for taking time answering my question! What did you eventually opt for? Our tender comes with 14k premium daikin ducted with 16.5kw rated heating capacity. Original heat load as computed by aircon technician is 19kw based on day time living areas. So he recommended either 16kw or 18kw. We upgradee our insulation level and window glazing. We also made windows smaller on east and west and bigger on north where the living area faces. Our climate zone is 65 which is cool temperate. After the uograde builder provided me Nathers report with 161.5 MJ/square meter-year heating load. My daytime living area is 105 sq meters. Convert all MJ to Kw. Resulting to around 12.90kw this we didn’t upgrade and just happy with 14kw. Moreover, builder quoted $5900 for 16kw upgrade and $8000 for 18kw. Too expensive. I said to myself the upgrade price can buy another brand new unit. Just save the money and spend it when in the future when the old one fails. I think the smaller unit is cheaper to run based on our use. While glazing upgrade for windows a bit dear. And insulation isn’t significant, I think they are better options for me. Re: Which ducted aircon size? Daikin 16kW or 18kW? 15Sep 15, 2021 6:47 pm Leona33 Ceddy_83 Leona33 Wow! This is the best about online community! l learned a lot! Thank you for taking time answering my question! What did you eventually opt for? Our tender comes with 14k premium daikin ducted with 16.5kw rated heating capacity. Original heat load as computed by aircon technician is 19kw based on day time living areas. So he recommended either 16kw or 18kw. We upgradee our insulation level and window glazing. We also made windows smaller on east and west and bigger on north where the living area faces. Our climate zone is 65 which is cool temperate. After the uograde builder provided me Nathers report with 161.5 MJ/square meter-year heating load. My daytime living area is 105 sq meters. Convert all MJ to Kw. Resulting to around 12.90kw this we didn’t upgrade and just happy with 14kw. Moreover, builder quoted $5900 for 16kw upgrade and $8000 for 18kw. Too expensive. I said to myself the upgrade price can buy another brand new unit. Just save the money and spend it when in the future when the old one fails. I think the smaller unit is cheaper to run based on our use. While glazing upgrade for windows a bit dear. And insulation isn’t significant, I think they are better options for me. That's good outcome. May I ask how did you convert the MJ/Sq into KW to get the 12.90kw rating. I am also trying to find out mine so just wondering if you can please help. Just trying to size the approximate kW rating for AC. Re: Which ducted aircon size? Daikin 16kW or 18kW? 16Sep 15, 2021 7:13 pm Leona33 Ceddy_83 Leona33 Wow! This is the best about online community! l learned a lot! Thank you for taking time answering my question! What did you eventually opt for? Our tender comes with 14k premium daikin ducted with 16.5kw rated heating capacity. Original heat load as computed by aircon technician is 19kw based on day time living areas. So he recommended either 16kw or 18kw. We upgradee our insulation level and window glazing. We also made windows smaller on east and west and bigger on north where the living area faces. Our climate zone is 65 which is cool temperate. After the uograde builder provided me Nathers report with 161.5 MJ/square meter-year heating load. My daytime living area is 105 sq meters. Convert all MJ to Kw. Resulting to around 12.90kw this we didn’t upgrade and just happy with 14kw. Moreover, builder quoted $5900 for 16kw upgrade and $8000 for 18kw. Too expensive. I said to myself the upgrade price can buy another brand new unit. Just save the money and spend it when in the future when the old one fails. I think the smaller unit is cheaper to run based on our use. While glazing upgrade for windows a bit dear. And insulation isn’t significant, I think they are better options for me. Great outcome!! The unit normally clips into a metal plate screwed to the wall, either plate is not flush, or unit not hooked in and could be hanging from the pipes partly, either might… 2 15773 retail its around double the price of a similar sized actron/dakin system from memory, They are excellent systems though. But with how builder gouge on AC/heating, you… 4 13736 Dear Members I have to decide the Facade column size. My custom builder standard is 350mm with rendering, but i asked for 470mm plus stone or tiles and yet to get… 0 7492 |