I want to exhaust the steam in the shower directly to the outside via a duct. I was told it was against the recent changes in the Australia electrical code to install an exhaust fan directly above the shower. Does anyone know of a product that complies with the ccode , or a way around this problem?
exhaust fan above shower not possible?
(21 posts) (13 voices)-
Annette
MemberHas your plumber made any suggestions?
The Beacon Lighting website says '...it’s recommended to use a ducted in- roof mounted exhaust fan. This allows the extract grille to be installed directly above the shower for maximum efficiency whilst maintaining electrical safety with the fan being remote from any Water spray'
Or, why not put the fan just outside the shower?
Posted Wednesday 23 Sep 2015 @ 9:12:52 am from IP # -
Lizzie
MemberI was told by electricans that it is now against Australian code to put any electrical appliance above the shower that was more than 12 volts. Further, the written statements on exhaust fans (such as the one you suggest) is technically incorrect and no electrican will install it if they want to act within the law.
I want to put the exhaust fan above the shower because that is where the steam in the room comes from, and i want to get it out of the bathroom before it spreads all around the room.
There is an additional problem in ducting the steam to the exterior of the building. If the duct goes to an external exit grille in the eaves, you are trying to get the steam to move horizontally, then slightly downward, instead of natural path of vertically. If you duct the steam vertically to a an external vent on the roof ridge, there is the problem that the steam can condense in the cooler duct, and flow back down into the exhaust fan.
i asked several electrical wholesalers for a solution to this problem. They confirmed what I wrote above, and said that there was no available solution. Someone needs to find one.
Posted Wednesday 23 Sep 2015 @ 11:33:47 am from IP # -
cravenhaven
MemberI generally try to avoid having the fan directly above the shower because it creates a cold draft. my suggestion is to place it half a metre or so away from the shower cubicle.
As far as moving the steam out, once it is under the influence of the fan it will go where its pushed whether its up, down or sideways. Maybe if the duct pipe is smooth walled and sloped slightly downwards towards the eaves the problem might be reduced.
And talking about condensation is another reason to have the fan somewhere other than directly above the shower. I have showered in such situations before and got nice cold drips on me from the condensation out of the fan vent.Posted Wednesday 23 Sep 2015 @ 11:54:35 am from IP # -
Annette
Membercravenhaven said:
As far as moving the steam out, once it is under the influence of the fan it will go where its pushedJust need to ensure that there is enough air coming into the room to create air flow (through slightly open window or crack under door etc).
If several electricians have said that a fan can't be installed above the shower, then I guess it can't. On the other hand, Iots of people have fans that aren't above the shower and they seem to work OK.
Posted Wednesday 23 Sep 2015 @ 1:01:14 pm from IP # -
Oilburner
MemberIn my bathroom I have one of those IXL tastic light/ heater/ fan combos right in the middle of the room. It's at least 4 ft from the closest part of the shower and probably 6ft from the far side.
With the fan running you can have a scalding shower and the mirror on the far side never gets any condensation nor does any other part of the room.
I think you are over thinking and making mountains out of molehills with this. What would be the big deal if you did get a bit of steam in the bathroom anyway? I never put the fan on because it makes the room too damn cold with the draft it creates. When the cold isn't a problem, the steam rarely is in the first place so its all a bit of a moot point.
I can see plenty of problems with ducting the exhaust outside. Firstly it will be a hell of a heat loss in winter. Then there is the thing with ingress of birds, Rats and various other insects and wild life. What is so terrible about ducting the vent into the roof cavity like always? Thats where mine goes and I have never heard of a problem with this arrangement.
Posted Wednesday 23 Sep 2015 @ 6:30:29 pm from IP # -
Annette
MemberHi Oilburner
The problem with ducting into the roof with a sealed roof space (even with just a corro roof with RFL or anticon blanket ) is that the moist air creates condensation that can't escape.
This has been an emerging issue with mould forming in the roof, condensation dripping and staining/ saturating plaster ceilings underneath and 'sick building syndrome' http://www.abcb.gov.au/education-events-resources/publications/~/media/Files/Download%20Documents/Education%20and%20Training/Handbooks/2011_CondensationHandbook.ashx
With unsarked tiled roofs, possibly not such an issue if there is a fair amount of air flow in the roof space.
But in sealed roofs, moist air from cooking etc should be ducted outside.
Posted Wednesday 23 Sep 2015 @ 8:56:19 pm from IP # -
Lizzie
MemberThis is a proposed new build, in which i am hoping to avoid the problems i have with the house in which i am currently living. I have an exhaust fan in the middle of a fairly small bathroom, and i always shower with the bathroom window wide open,. In fact the bathroom window is rarely ever closed. But the steam rises to the ceiling above the shower and stays there for a long time. It makes the ceiling mouldy. I take this as a sign that something needs to be fixed.
The new build is in the country in a bushfire rated zone. I plan to follow the recommendations in the Bradford Bushfire Design Guide and install Anticon to the whole of the underside of the metal roof. To address any condensation issues in the roof, i am installing bushfire proof vents at the roof ridge line. To also prevent condensation in the roof, i need to duct all exhausts directly to the exterior.
i recognise that i may be obsessing about this, but i prefer to consider the matter carefully before perhaps repeating faulty past building practices.
Posted Wednesday 23 Sep 2015 @ 9:34:24 pm from IP # -
Annette
MemberAlso worth checking the capacity of the fan. You might need a more powerful one.
In my bathroom, mould was forming despite using the fan. I installed a second fan in addition to the small 1980s one that came with the light. I then realised that the mesh vent around the old fan was completely blocked - and cleaning it improved its performance.
Not sure which action made the most difference - both probably - but the current tenant says there is no longer any mould.
Posted Wednesday 23 Sep 2015 @ 9:45:18 pm from IP # -
ncl_knight
MemberI've got a solar star that is not directly over, but just offset from the shower cubicle. The window has vents that are always open, and it runs all day. We have no issues with it. Works fantastic. It doesn't need a sunny day to run, just light. Obviously it works faster in full sun, but we have a small bathroom and bnever have any mold or moisture issues.
Posted Wednesday 23 Sep 2015 @ 10:52:19 pm from IP # -
scott drew
MemberLizzie, perhaps you can utilise the normal fan extraction systems available but alter something else seeing as you are starting from scratch?
What about orientating the bathroom so it faces north and has large window space so every sunny day the room gets heaps of light which will naturally dry the room and inhibit mould growth anyway? The window doesn't need to be a window either. What about a glass brick wall or similar? Orientation and lots of light may assist in naturally drying the room rather than redesigning a fan/exhaust system.
Maybe this suggestion combined with the one about of a solar fan that continually runs when light may be a compromise you can build into your bathroom from scratch?
Posted Thursday 24 Sep 2015 @ 12:00:24 am from IP # -
Indali
MemberHi Lizzie,
I think a bit of obsessing on bathroom fans is good. I certainly did on our place. Thankfully it has paid off with minimal steam accumulation in the shower even in the middle of winter and that clears very rapidly when the shower turns off. No more fogged mirrors either. This is even though we have a twin shower. Here are the things we did:
- made sure the fan was sized adequately (not at the minimum required). From memory I aimed at 15 air changes per hour, so every 4 minutes the air in the bathroom is expelled. A quick internet search suggests aiming at 11-20 air exchanges per hour. Depending on your bathroom size a standard in ceiling extraction fane may not achieve this.
- placed the fan away from the door/window to maximise cross ventilation and flushing of the air.
- added a timer so the fan runs for a few minutes after it is switched off to make sure most of the moisture is extracted.
- made sure the ceiling (and walls) were insulated so that there wasn't a cold surface to encourage the steam to condense.
- as our showers are opposite the doors/windows our fans were also above the showers. We placed the fan remotely away from the bathroom ceiling and then put ducting from the ceiling to the remotely mounted in-line duct fan. I did this mostly as I hate fan noise and now it is nearly silent. This also kept the fan itself out of the splash zone so no problems with electrical compliance. (If you want to minimise fan noise then hang the fan on some straps or springs to further reduce the noise)
- we put a self closing damper in the duct so when the fane is off, the duct is closed so we don't get cold drafts.
It is also worth noting that the fan is much much stronger than the buoyancy forces that makes steam rise so a fan has no troubles pushing the steam horizontally or downwards. If the duct runs downwards it actually has the advantage of draining any water that condenses in the duct outside.
Mould is not good for either you or the building so persevere!
Posted Thursday 24 Sep 2015 @ 5:24:24 am from IP # -
Lizzie
MemberThanks everyone for your suggestions, it is very much appreciated.
As the new build is to be in a zone with similar climate to Canberra, i want to make sure that insulate well while reducing condensation problems with good ventilation. I realise that the ideal passivhaus solution would be a good heat recovery system for the whole house, but due to cost, i am trying to get similar type of results by juggling the different elements.
Yes, i will be getting an oversized fan with backdraft flaps, with a metallic antibushfire exit grille for the duct. I want to keep the bathrooms on the southside, as per all the advice i had read on passive solar house design.
I was hoping that someone might have had a failsafe solution to control condensation that i was unaware of.Its interesting that the written description of the current fans say they can be placed above the shower. But the electrical retailers told me that this was incorrect due to recent building code changes. When i questioned how such descripitions were allowed to be used onthe packaging ifthey were technically untrue, i was told that the loophole was that the fans were directed to be installed ac ording to the code (which now forbade installation above a shower). "The electricians know this".
Thanks for your feedback and suggestions
ONCE AGAIN, THANKS EVERYONE.Posted Thursday 24 Sep 2015 @ 7:28:08 am from IP # -
Greg C
MemberI have a ducted fan beside the shower. Both are on the opposite side to the window, but it clears steam from the room very efficiently.
In our other bathroom the fan is directly above the shower/bath. Never had a problem in 27 years although this does not clear the room as efficiently as the other because it is next to the window.
Posted Thursday 24 Sep 2015 @ 11:04:37 am from IP # -
David
MemberNo problem placing suitable fan above the shower, or use a ducted fan that will cover the issue you mention. It's about the ZONE it's located in and how it might be accessed replace it or repair it. There are and we've used suitable product/s and installed them to do exactly what your asking about no big issue at all.
Posted Thursday 24 Sep 2015 @ 11:11:54 am from IP # -
A fan directly above the shower is in fact possible . As the poster above mentions it is dependent upon the zone. Which basically means height of the electrical appliance above the floor level . see link ;http://www.rm-electrical.com/technical/bathroom-zones-explained/.
The way we did it was by using an inline fan with the fan connected to ducting well above the ceiling line . Much more efficient too . Your other choice is low voltage fans .Either way a fan directly above a shower is a great idea .And don't forget to duct it out of the ceiling cavity .Posted Friday 25 Sep 2015 @ 3:41:06 am from IP # -
Flying high
MemberWe have an exhaust fan in the middle of our onsuite ceiling, its the one with opening and closing blades, (HPM) its about 27 years old and still going, in fact it is so strong it will open the bifold doors. The blades when closed to a good job closing off drafts as opposed to a plain exhaust fan however, I purchased a draft stopper to further assist in reducing any further drafts.
Anyway, we used to heat the ensuite with the ducted gas heating and then when showering turn on the exhaust fan...yes crazy, so all the heat and steam is removed from the room.
I saw somewhere on the web, an acrylic product called the shower dome, great idea but, IMO expensive.
I purchased something off ebay and it came with a sheet of perspex which I have placed above the shower frame/wall tiles (~ 1300 mm x 850 mm) just to try it out, same idea.
In a word, fantastic, all the steam/condensation stays with the shower cubicle and we don't even turn the fan on any more when showering. In fact, it is so warm within the shower cubicle it actually feels cold when existing the shower cubicle into the ensuite even though the room is still heated with the ducted gas heating (note, ensuite is zoned with a damper motor)
Now as for any mould and there was a small amount after 3 months, a quick spray and wipe with straight white vinegar has fixed this.
It's a simple and cheap fix and IMO its great.
Posted Saturday 26 Sep 2015 @ 11:51:42 pm from IP # -
David
MemberFlying high said:
We have an exhaust fan in the middle of our onsuite ceiling, its the one with opening and closing blades, (HPM) its about 27 years old and still going,That's great for a fan of that age, however regulations have changed and when or if it's required to be replaced at some stage, you'll run into AS3000 regs and the unit if within zone 0 will have to be an exhaust unit, that meets the current rules. Doesn't matter if it's the way it is now on replacement it'll have to meet the current regs of the day, whatever they are at that point.
Posted Sunday 27 Sep 2015 @ 9:54:02 am from IP # -
On the Solar star solution, I'd suggest having a look at a roof mounted solarwhiz. You can build a vent in the bathroom and duct it to the solarwhiz unit on the roof. The solarwhiz unit can optionally attach to the main power source so you can run it all day.
I think the "problem that the steam can condense in the cooler duct, and flow back down into the exhaust fan." is technically incorrect. Roof spaces are typically much warmer than the inside of the home - just spend some time in one! And condensation depends entirely on the Dew Point of the home. http://www.solair.com.au/What-Is-Dew-Point.php
Additionally, a solarwhiz ducting is not air tight, so in this case the air would descend into the roof space not back into the bathroom.
Alternatively, you could use positive pressure ventilation. A solar air heater collector such as the SolarVenti can pump in dry air and push out the damp, humid air naturally.
Posted Wednesday 25 May 2016 @ 6:41:02 am from IP #
