condensation on toilet cisterns

[desrob]

what causes this,(bad air circulation ?)..went to a house today and the condensation build up on the cistern was the worst i'd seen,the water temp is cold and the air temp warm is this causing or adding to the problem, he asked my advice and all i could come up with is for him to improve the air circulation within the room or get a humidifyer,any idea's ...?

 

[SimonG]

You hit it on the head, poor ventilation. You can get some sort of polystyrene liner for the inside to try and insulate the sanitaryware from the cold water, but I haven't seen a good one yet!

 

[desrob]

thanks simon

 

[Deleted member 25704]

Condensation in home is usually due to cooking, bathing and drying washing. Some dry their washing on the radiators, putting pints of moisture into atmosphere.

Solution, fit mechanical extraction in bathroom, and kitchen, and don't dry washing inside.

As for dehumidifyer - job for life emptying, and wasting your money on fuel and box that will go wrong.

 

[Howsie]

Ventilation, ventilation, ventilation. An air conditioner or dehumidifier work.

As has been said, tank insulation but these are hit and miss.

They use anti sweat valves in the US to mix a little hot water in the cistern. This works well but you'd probably need to run off a secondard return to make it work and I haven't seen them over here.

 

[Deleted member 25704]

Don't be fooled into treating symptoms - the moisture on the cistern is the symptom, not the cause

The cause is the moisture we make - make no moisture, get no condensation.

Insulating the cistern just treats the symptoms - however, the Grohe, plastic cisterns have a layer of polystyrene inside - plastic cisterns = low cost housing = drying washing inside, the Germans tooks steps!

 

[SimonG]

Hands up all those who don't dry washing inside with the great british climate!

 

[REDSAW]

thread and solutions posted 2 years ago.
the 'real' problem is winter, colder mains water, warmer/drier air indoors due to heating = condensation.
best solution = increase cold main temp or separate cistern from room ambient temperature.

 

[Guest123]

Need a good quality extractor fan designed for use in bathrooms. Even opening a door or window can help. It's generally a circulation problem that can be improved with good ventilation.

 

[Deleted member 25704]

thread and solutions posted 2 years ago.
the 'real' problem is winter, colder mains water, warmer/drier air indoors due to heating = condensation.
best solution = increase cold main temp or separate cistern from room ambient temperature.

If the air was dry and warm, then there would be no surface condensation on cistern.

However, showers and cooking, put vapour into the air, which then shows itself as surface condensation.

Regarding treatment, there is another way, which saves energy - fit a air recovery ventilation system. This extracts air from moisture zone such as bathroom, which passes through a heat exchanger to condense the vapour, the dry, warm, air is then circulated back into the dwelling. There is a double saving to be made here, the sensible heat already in the air is recovered, while the latent heat (gained as vapour changes to liquid - latent heat of fusion) is a bonus.

I think these types of units will be more popular than central heating in our well insulated houses of the future. Quiet Heat Recovery Unit - Ventilation Systems

 

[quality]

Good post but don't you mean latent heat of condensation ?

 

[Deleted member 25704]

Good post but don't you mean latent heat of condensation ?

Condensation = fusion of vapour molecules, in changing from gas to liquid

bit early for physics, but all good stuff!

 

[quality]

Gas to liquid is we call it condensing not fusion hence the condensation on the cistern not vapour fusing to it.
It all terminology but I know what you mean and agree its a bit early

 

[kay-jay]

don't forget the other contributor...............cheap pot from b and q etc.

you can try and insulate the cistern but reports say its pretty crap. feed bog off cwsc (insulated) in the loft, less difference in temp between feed water temp and ambient air temp will result in less condensation.

 

[Deleted member 25704]

Gas to liquid is we call it condensing not fusion hence the condensation on the cistern not vapour fusing to it.
It all terminology but I know what you mean and agree its a bit early

Quality,

For example - when showering in hot water, the air becomes moisture laden. This moisture, may be retained by the air - high humidity, without showing itself. When this moisture-laden air, meets a cold surface (wall, window, wc cistern) it condenses. The process of condensation, is the fusing back together of vapour molecules to form a liquid - this process gives up heat which is hidden or latent. So latent heat, is hidden in vapour, and given up, as vapour becomes a liquid.

Root cause analysis - creating vapour causes condensation

The surface-condensation or liquid on the cistern, comes from the moisture laden air in the room.

Solution - remove moisture at source - this is why mechanical extraction is building regulation requirement for bathrooms and kitchens.

This is not an opinion, its supported by building regs and scientific rationale

 

[quality]

Latent heat of fusion is when ice is formed not when vapour turns to liquid which which rejects latent heat due to condensation

 

[Deleted member 25704]

Latent heat of fusion is when ice is formed not when vapour turns to liquid which which rejects latent heat due to condensation

I think its both, but I could be wrong. Just did a wiki, for this but couldn't understand it.

Maybe you could explain.

 

[quality]

When water freezes or melts it rejects or absorbs latent heat measure in j/g this is known as latent heat of fusion.
When water evaporates or condenses it absorbs or rejects latent heat this is know as latent heat of evaporation or condensation.

 

[kirkgas]

worked in a boat repairer guys house yrs ago, and he had sprayed the inside of the cistern with fibreglass resin which gave an insulation level between the cold water and the hotter air in the bathroom, told him i didnt fancy the job of changing the syphon or ballcock when they went, but it seemed to work

 

[Deleted member 25704]

When water freezes or melts it rejects or absorbs latent heat measure in j/g this is known as latent heat of fusion.
When water evaporates or condenses it absorbs or rejects latent heat this is know as latent heat of evaporation or condensation.

Thanks for explanation quality,

My thinking of fusion is a coming together of molecules as in a gas changing to liquid, which is the opposite to vaporisation which is molecules moving apart, as in a liquid becoming a gas.

When a gas condenses, do the molecules fuse (move closer together) or do they move further apart?

Still can't get my head around that bit.

Thanks for your reply.

 

[quality]

Google enthalpy of fusion that should help

Ps sorry to the OP for the thread hiijack

 

[Simon F]

I bought a de humidifier about 4 years ago. instant fix to all internal condensation, wc cistern and windows. Easy solution for about £80. Its true that they use electricity and need emptying, but there is also heat given of. I would always recomend using one.

 

[REDSAW]

for gawd sake, box it in.

 

[Hybrid]

If it's causing major problem feed from cistern in loft, gives the incoming water a chance to get up to temp.

 

[SimonG]

This thread needs forwarding to 'new scientist' magazine Interesting though.