Condensation?

[Ex- Member]

That's not quite true.

 

While you are correct that insulation does not

reduce the quantity of water vapour in the air, you are incorrect when you say

that if it doesn't condense on a cold surface it will just condense somewhere

else. Water vapour doesn't have to condense on surfaces at all - it can remain

in the air, and the warmer the air the more water vapour it can contain.

 

 

Absolutely we have loads of soft furnishings and stored clothes and bedding, non of which are in any way damp or even dank, the amount of dust they contain is evidence of that

 

We been living aboard full time for over 3 monhs and in the past month relied solely on the bubble stove which has a max 4kw output, we were worried it wouldn't be enough heat but so far it's been ample and mostly run on minimum setting until ot goes over -1 ouside temp. We heat the whole boat which is open plan using 4 small rads, tthe even distribution of heat is imporant which I believe helps with regard to condensation, we manage to keep the boat between 19 & 21c witth stove on a minimum setting.

 

 

As mentioned there's plenty of ventilation available other than mushroom vents which are mostly blocked through the winter as they simply waste heat.

 

Our insulation is Rockwell and not sprayfoam, but the rockwool was fitted properly and we haven't suffered any drips through lining or into bilge Although there's no doubt there will be some occuring somewhere.

 

 

Overall very happy, as the insulation and heating were our main worries, could do with some colder temperatures to fully test though.

[blackrose]

Within the norms of our real world and the temperatures we actually live in, the process of heat/expansion and rising dew point has a practical limit.

 

Given the amount of water a single adult sweats just sitting still, the air on a boat that is not ventilated, even if you have it as hot as a sauna, will either condense into water on a cool surface or leave some of its moisture on all your ‘spongey’ soft furnishings.

 

Of course, if you were cruising in an orbit close to the sun, in the vacuum of space then ……

 

Now you're drifting into the realms of fantasy....

 

I don't have extra ventilation in my boat in winter (apart from when I have a shower), other than having 4 mushroom vents in the roof and 4 vents in the bow and stern doors and I don't get any condensation on soft furnishings. I get a little on the windows but that's to be expected.

 

Most boats are well ventilated - or at least they should be if they follow the safety recommendations and have plenty of non-closable vents, both in the roof and at low level.

 

I never understand it when this topic comes up and everyone starts screaming about ventilation. Most canal boats have plenty of fixed ventilation.

Edited January 22, 2013 by blackrose

[Joshua]

 

 

Most boats are well ventilated - or at least they should be if they follow the safety recommendations and have plenty of non-closable vents, both in the roof and at low level.

 

I never understand it when this topic comes up and everyone starts screaming about ventilation. Most canal boats have plenty of fixed ventilation.

 

I am sure you will have read the thread before posting so will know that I certainly wouldn’t disagree.

 

As for the “screaming” and suggestion that most narrowboats don’t have enough ventilation, unless the screaming is your own, there must be a parallel thread you are getting confused with.

 

Of course, it is worth pointing out that whilst most narrowboats may well be designed with good ventilation, Julynian has nicely pointed out just how easy it is for an owner to circumvent (no pun intended) that design.

 

To avoid any doubt, I am not suggesting Julynian, that your boat lacks adequate ventilation, even after your modifications, in fact, if you don’t have any condensation or dampness in your boat then I would argue that your ventilation must be perfect.

 

 

[BGA]

I suppose if you had several de-humidifiers you could save trips to fill the water tank or would that be considered unhealthy?

[chazzy]

I suppose if you had several de-humidifiers you could save trips to fill the water tank or would that be considered unhealthy?

Can be done...My link I think not on a narrow boat though.

[Richard Famous]

Hi, I have a fairly new boat and we get minimal condensation and we deal with it as you would expect. The biggest problem I found was a small drip coming out of the pressure release valve on top of the calorifier. As it reaches working temperature a drip appears every second or so. Before I found this, the drip simply went into the bilges and added up to quite a flood. When I found the drip it was obvious. I have simply attcahed a flexible garden hose to a clear bottle which I empty as needed. I don't know if this might be the cause of your problem but it's worth looking at.

[Simon (Hawksmoor)]

Where do you think all the humidity goes then?

 

If you don’t vent it, your soft furnishings will have to soak it up instead, it has to go somewhere.

 

A window is a great dehumidifier.

If you regularly squeegee away the condensation so it runs out of the drain hole you are removing the humidity from the air.

[system 4-50]

Hi, I have a fairly new boat and we get minimal condensation and we deal with it as you would expect. The biggest problem I found was a small drip coming out of the pressure release valve on top of the calorifier. As it reaches working temperature a drip appears every second or so. Before I found this, the drip simply went into the bilges and added up to quite a flood. When I found the drip it was obvious. I have simply attcahed a flexible garden hose to a clear bottle which I empty as needed. I don't know if this might be the cause of your problem but it's worth looking at.

I expected you to get a quick response to this but none has appeared so I will volunteer my penn'orth.

 

This will cause you problems as your PRV will eventually clog up. Your PRV valve should not routinely weep. Your expansion tank is either missing, miss-set or faulty?

 

 

[Richard Famous]

I expected you to get a quick response to this but none has appeared so I will volunteer my penn'orth.

 

This will cause you problems as your PRV will eventually clog up. Your PRV valve should not routinely weep. Your expansion tank is either missing, miss-set or faulty?

 

Hi, Thanks for responding. You have prompted me to look further. There are threads on this site and elsewhere on the net so I'll take some time reviewing them (as well as looking again at the instructions, the expansion tank and the PRV itself).

 

Thanks again.

 

Richard