activated charcoal & toilet smells...

[js.b1]

In a conventional toilet smells are exhausted by a high level fan, typically 60m^3/hr run for 10-15mins.

When the toilet is a commode in a bedroom, with irritable bowel syndrome, the odour issue is more complicated. The commode is mainly re convenience, there are no major health issues - just eczema foot bandaging significantly restricts mobility and profile bed keeps it up and actually damn comfortable for her!

1 - Fit a high level fan on 15min runback timer? May require compensatory heating since bedrooms tend to be cool. =A327 for a decent Xpelair DX100PC fan.

2 - Fit a hydroponic 4" duct fan & duct & activated charcoal filter? Does not expel room heat, just moves air through a large charcoal drum filter. Noise is high, but they are powerful for smelly plants so running time may be short. =A375 for a kit.

3 - Fit a fancy 2lb activated charcoal equipped with HEPA air purifier? Does not expel room heat, noise is low so running time is longer. Limited to 2lb charcoal, expensive filters. =A3220 for a unit, =A370 filters a year.

I never recall the activated charcoal things working that well with recirculating cooker hoods, either in speed or absolute removal. I know HEPA filters work for allergies, I picked up a big Honeywell drum HEPA unit for =A349 a decade ago and it eliminated hayfever totally (replacing it by near complete deafness :-)

A fan extract seems to be a simple cheap solution, and improves general ventilation in the bedroom. A window is easy to open, but they are very large and a bit brutal in January.

Thoughts?

[Andrew Gabriel]

2 weeks later, woken up in the middle of the night by 50 drug squad officers breaking in, only to find her sitting on a commode...

You'd need to do some tests to see if charcoal can quickly absorb the smells.

25 years ago, I saw a kit in Texas Homecare (or whatever it was called) which I really liked the look of. It was an extract fan which installed inside the toilet cystern, sucked the air up the flush pipe and expelled it outside through the toilet overflow pipe. This stopped the smell ever getting out into the room in the first place, and thus the volume of air to extract would be very much less.

Could you design something like this into the commode, extracting from under the seat rim so that the commode is at a slight negative pressure?

[js.b1]

Heh-heh. We and about 3000 other people live in a corridor between two council estates build later in the 1960s. Police helicopter is a quite common sight above either of them, sadly & noisily :-)

I suspect so. The hydroponic stuff sells well, so cost of failure is recoverable. Gardeners world must be proud of so many green fingers...

That is a perfect solution.

Unfortunately they use a pan. Gordon Ellis Royal, essentially a chair with an 18x18 blow-moulded polypropylene insert into which a polypropylene pan is dropped. It is surprising

A wall fan is out re #1 road noise & #2 shutter rattle in prevailing wind. However there is a lot of space under the commode, so I think it may be possible to couple a fan and 4" charcoal duct filter in there.

[McGyver]

All filter solutions will be slow. So slow that the total amount of air moved will be as much as the exhaust fan solutions. Exhaust fan solutions will be fast. I would opt for speed, even at the cost of heat, and I'm not convinced that there will be any difference in heat loss. I haven't thought this through, but you could go with a very short timer. 15 minutes is far too long. One minute longer than it takes to get back into bed should be more than enough.

There will be a bit of noise, but there are techniques to minimize it.

McGyver

[js.b1]

I have actually gone with the fan solution... :-) ... gets odour out, fresh air in - the room lacks ventilation ... cheap to reheat a volume air, not heating building bricks ... cheap to do

An 4" Xpelair DX100 Pull Cord for =A324, EBM-Papst german motor, not too noisy, arrived yesterday and I will core drill the wall in the next few days as long as a dry hour or two.

Eventually I will fit something like a AIRFLOW Quiet Extractor Fan QT100T which is quieter at 25dB(A), runs on a timer adjustable

6-21mins every 4 8 12 24hrs etc. Basically a "freshen the air" fan. Will fit a cowled outlet with backdraught damper to avoid the "gravity shutter clatter" in the gusts re bedroom. For now pull cord will be fine.