Browse Forums Heating, Cooling & Insulation 1 Aug 08, 2009 6:54 am Hi, we recently got a deal on grays for 10x ceiling fans and they are 43" just wanted to know what sort of coverage am i expected to get from 1x ceiling fan? its not something i checked before i probably should of! thanks -Nathan 2nd-Fix | Blog Building with Desyn Homes previously with the insolvent [url=https://www.facebook.com/7NewsAdelaide/videos/1162546323776021/]Endeavour Homes[/url] Re: Coverage on Ceiling Fans 3Aug 08, 2009 8:12 pm It's hard to get good info on this subject. Some sources talk about how much air is being moved (cfm or m3/hr) and other refer to the speed of the movement (ft/sec or m/s). There are some brands that claim to be have highly efficient flow rates due to the fan shape. Most ceiling fan manufacturers don't give specifics about how much air they move per hour and aren't very helpful on their websites. Ceiling fans don't operate in the same environment as ducted fans. Air is churned around the room rather than being pulled from one end to the other. Summer evaporative cooling is directly related to the speed of air movement across the skin which according to the Your Home technical manual reaches its maximum effectiveness at 7.5m/s. This sensation can be uncomfortable in winter. Many fans have a 'winter' up-draught mode so that you aren't subjected to a blast of air. In winter the fans help recirculate hot air that has stratified towards the ceiling and push it back towards the floor. I saw a study which measured air speed. It dropped rapidly beyond the tips of the blade. The simplest rules of thumb are based on room size for given blade diameter. You can find lots of references on the web for this. Here is one example: http://edis.ifas.ufl.edu/FY1029 A more technical one based on room volume is here: http://www.energystar.gov/ia/products/h ... H142PA.pdf Try to use the largest fan that can fit comfortably in a room. They generate more flow for a given RPM so can be run quieter. An additional recommendation is not to centre the fan in the room. The idea is to guide the air flow down one wall so it can flow across and then up the other side in a circulating rather than chaotic pattern. In a large room setting one fan to up-draught mode and the other to down-draught is supposed to assist this effect Re: Coverage on Ceiling Fans 5Aug 08, 2009 10:07 pm Carmel This would do my head in. Can you go to someone's house and stand under their fan? This is what we used: 48' (120cm) for a 12m2 room 52' (130 cm) for a 16.8m2 room and 20m2 room 2 x 56' (140cm) for a 70m2 room Re: Coverage on Ceiling Fans 6Aug 08, 2009 10:12 pm dymonite69 Carmel This would do my head in. Can you go to someone's house and stand under their fan? This is what we used: 48' (120cm) for a 12m2 room 52' (130 cm) for a 16.8m2 room and 20m2 room 2 x 56' (140cm) for a 70m2 room What brand did you go for? and what are they like for noise? Thanks Re: Coverage on Ceiling Fans 7Aug 08, 2009 10:45 pm mikemix dymonite69 Carmel This would do my head in. Can you go to someone's house and stand under their fan? This is what we used: 48' (120cm) for a 12m2 room 52' (130 cm) for a 16.8m2 room and 20m2 room 2 x 56' (140cm) for a 70m2 room What brand did you go for? and what are they like for noise? Thanks He got Hunter Pacific. They are mid-range in price. We previously owned them and they seemed to work OK. They are an Aussie brand and have a decent 2+3 year warranty. We bought the Typhoon model (we opted for SS finish which we found out later is more expensive than the other colours). They ranged from $160 to $220 each. Metal fans make more noise as they 'cut' the air but ours are only irritatingly noticeable at full speed. The previous ones were still working well after 3-4 years. Blade length is more important than blade number. You can spend quite a lot of fans. My colleague got ones at $500 each. Re: Coverage on Ceiling Fans 8Aug 09, 2009 10:51 am thanks yak and d69, now we have some idea about how many per room; just hope we have enough now ive also heard that metal blades generate more noise, and bigger is better as it requires the fan to spin less for cfm. -Nathan 2nd-Fix | Blog Building with Desyn Homes previously with the insolvent [url=https://www.facebook.com/7NewsAdelaide/videos/1162546323776021/]Endeavour Homes[/url] Re: Coverage on Ceiling Fans 9Aug 09, 2009 3:12 pm Choice published results of their ceiling fans' tests on-line http://www.choice.com.au/viewArticle.aspx?id=105890&catId=100519&tid=100008 Those with no access can pop into the nearest library. Chris My father rode a camel, I drive a car, my son flies in a jetliner, his son will ride a camel.Saudi saying Re: Coverage on Ceiling Fans 10Aug 10, 2009 8:11 pm I've never found metal blades noisy except on flat out, and they never used to get turned off for almost all the year. They helped stop the mould gorwingin the ceilings. And article re scientific measurement and fan tip being the limit. http://www.fsec.ucf.edu/en/publications/pdf/FSEC-CR-1770-98.pdf and I'd recommend the offset placement as being best to create a cyclic effect of air movement through the room. Mind you - Directly mounted above the bed on a stinking hot night and the fan on flat out is always effective. It looks like Blacktown council allows up to a 6.0m wide driveway so just ask your builder to change the plans. If you are just in the planning stage then there is no… 6 3881 How do you remove one of these ceiling air con vents? And is it possible to disconnect the duct joined to the vent from inside the house, without going into the roof cavity? 0 5943 There is water getting into the ceiling, I expected to find some holes in the corrugated roof but there weren't any so I suspect that the roof drip edge is letting water… 0 2452 |