High humidity and condensation

dampdaveski

Hi Ix,
I have a Dri 2000 in my house without a heater, though my landing is probably bigger than your cottage's. I have no issues with it cooling the house down.
I also recommend and fit the full drimaster range of fans, I also fit a few envirovent units, these are just as good but no better, they are more expensive than nuaires products and they won't discount (fools)
At the mo we're fitting anything upto 10 a week (not this close to christmas though)
You could buy one and fit it yourself IF you are a competent person to do it, they ain't difficult to fit BUT I would always have to recommend that you get a qualified electrician to fit it.
You can buy one direct from nuaire
www.nuaire.co.uk or from www.condensationproducts.co.uk I buy from both these peeps as the latter have mould treatment kits that I use regularly.
there are 2 other suppliers that I know of, however having had unpleasant experiences with both I won't give you their web addresses (they p###ed me off big time)

Regarding giving a greater amount of energy into your home than it uses, they do i'm sure, will you ever notice it - absolutely not!
Don't buy a drimaster or similar system expecting your heating bills to halve because they won't, in the same vein they won't particularly rise either and they WILL manage the condensation problem in your home.
Hope this helps
DD

2Sheds

naepace wrote: »

How long has the drimaster been running ? It took a couple of weeks before I started seeing real results. Also, is there sufficient ventilation in your loft space & is the loft sealed from ceiling level i.e hatch, downlights etc. to prevent moisture laden air getting into your loft space.

We've had the drimaster 2 months now, as its the 3S model it has a different diffuser than the standard ones. I've partially blocked off the side that blows down the stairs to see if that will help.

Alas no change, the back bedroom windows are soaked and need wiping down with a towel every morning, while the front bedroom, only has a tiny bit of condensation along the bottom. As it a townhouse house we have another bedroom on the middle floor and that is soaked with condensation too. I've took photos and will be drawing up a floor plan to send onto nuaire's techinical folk.

Next door neighbours either side, no condensation even in the bedroom!!!

Wonder if we've got 'cheap' double glazing, if there is such a thing

Fire_Fox

If the Drimaster is sucking in air from your loft, is it damp up there? Are you sleeping with the bedroom doors closed but your neighbours sleep with them open?

2Sheds

Fire_Fox wrote: »

If the Drimaster is sucking in air from your loft, is it damp up there? Are you sleeping with the bedroom doors closed but your neighbours sleep with them open?

The loft is nice and dry, as for the neighbours I've spoke to half a dozen so can't all be sleeping with doors open.

We turned the drimaster up to 5 now (which is a bit high for a small landing) and partially blocked off the side blowing downstairs into the open plan lounge. So we'll see if that helps over the next few days. Otherwise I may have to move it

quietheart

Could I have some advice as well please?!
We have a 30s detached and have had some condensation problems. We've improved the situation with double glazing. Our roof felt isn't breathable and we've had mildew growing on the timbers. We've had a reputable damp company out who thinks we just need to cut the felt back around the vents to improve airflow.
The told us we don't actually 'need' it but I was interested in the Envirovent system. It would just give me peace of mind and I could stop using my noisy dehumidifier. I believe it costs around £600 - is that reasonable? Does it make any noise. Can anyone tell me of any disadvantages?
Many thanks

follyfoot

David_Aldred wrote: »

Hi,
Excellant that you are able to measure the relative humidity yourself and you really need a thermometer to measure the room temp and surface temps too.

Naturally occurring mould will flourish from around 74%RH so you can see you are well above this level so no wonder you have mould. The temps are very important as the dew point (the temp at which condensation will occur) varies with the temp.

For example at 80%RH if your room temp was say 16 deg Celcius the dew point would be 12 deg Celcius so any surface temp you measure to walls / floors / ceilings at or below that temp will have condensation with associated mould form on it.

If the room temp is 18 deg C at still 80%RH the dew point will be higher at 15 deg C and equally if the room temp is lower say at night / when you are out and drops to say 10 deg C at 80%RH then the dew point will also drop to 7 deg C so you can see how / why tboth air and surface temperatures are so important as well as relative humidity figures.

People will say they don't see condensation but it is when they are out or at night and the temp falls such that what the air could hold as a vapour at one level of temperature it can no longer hold at a lower temp and accordingly condenses out.

Relative humidity of 80-90%RH is high and wood is wet at 85%RH so you need to get this down by all the usual means. Humidistat controlled extractor fans (not manual) of sufficient capacity set to a level below which mould will occur and to overrun at least 15 minutes fitted by NICEIC electrican to all bathrooms, utility, and kitchen. Background controllable ventilation to all rooms either through window heads and doors. Consider self closers to kitchen utility and bathroom doors - keep closed when cooking / bathing and open windows within these areas during such events. Fit PIV units if you can afford them and check any voids beneath suspended timber ground floors are not wet and evaporating up into your rooms compounding the problem. If they are this needs to be addressed by opening up / sub floor ventilation and additional works. Having a boiler thermostat that hunts for minimum temps (say 15 deg C and trips in and out to meet them rather than on a simple clock so the property does not go cold will also help.

At 90%RH at a room temp of say 16 deg C the dew point is only 14 deg C so the walls and other surfaces only have to be 2 deg C lower than the air temp in the rooms and you will have condensation but in truth 90%RH is a saturated environement in which to live and will not be doing you and your house / possessions any good at all. The products of mould growth will make you poorly.

Insulating the loft void by applying insulation on the horizontal ceiling makes the air above the insulation (i.e. on the cold side of it) colder than it used to be before you insulated the loft void. Older houses (and even some modern ones) are not designed to function for this occurence and the dew point within the loft void is lowered such that condensation / mould occurs more readily.

To make it worse if the property was old there may have been ventilation through the roof covering slates / tiles because there was a lack of roofing felt. If the roof has been stripped and re-roofed using a non breathable roofing felt this reduces ventilation through the roof void and as a result the relative humidty within the loft void may go up and the risk of condensation especially if the ceilings have been insulated consequentially goes up.

There should be at least 50mm between top of insulation to ceilings and underside of roof covering and if condensation within the roof void is confirmed steps should be taken to improve the roof void ventiation at both the eaves and high level to encourage cross ventilation of the roof space. If there is no soffit board at the eaves within which to fit vents (that should include insect protection) then under slate or under tile vents can be fitted in this area (see Redland or other tile / slate manufacturer websites) along with ridge vents all in accordance with the Building Regulations.

A small de-humidifier of the types sold in DIY and other chain stores tend to be only effective within the room they are placed. There may be some benefit in hiring an industrial sized unit for a short period as these are more up to the job to remove chronic levels of realtive humidity and dry the fabric of the building down. Remember everything wants to be in equilibrium and decorations / plaster / wood etc will all readily absorb this excess humidity until in balance with it. If this is sustained a moisture resevoir builds up within the fabric of the building that will make the situation continuous rather than transient such that the property will remain dampe ven during more favourable weather / temperatures.

Keep observing the relative humidity and room / loft and surface temps especially when the property is at its coldest and adjust ventilation / heating and insulation until an appropriate balance is achieved that takes you out of the dew point ranges for all temps within the property though minor transient condensation will always tend to be an issue such as when you take an ice cold beer or bottle of wine out of the fridge

I hope these general comments help. Kindest regards David Aldred independent dampness and timber surveyor.

Can you recommend a dehumidifier? I was going to buy anti-mould emulsion from Biokill but not sure if i am just buying expensive paint.

follyfoot

dampdaveski wrote: »

2sheds
The Driheater is a 500 watt heater, this doesn't run continously, but pulses, you can also adjust them to only come on at really low temperatures

ceebeeby,
easiest and cheapest option is to get a mould control kit, which has a mould killer in it and an additive to put in the paint
You will be able to get kits from
www.dampshop.com
www.twistfix.co.uk
www.dampness-info.co.uk
and both from my main supplier
www.condensationproducts.co.uk (kits are miles better but I'm byast as I get discount for buying in bulk off them )
though to be honest you might the dri heater cheaper directly from nuaire
www.nuaire.co.uk Their supply arm is fans direct, their number is 0844 5830044 (based in Leeds)
Hope this helps
DD

Hi do these products eradicate mould? If so, can my flat still suffer from condensation?

marshallka

naepace wrote: »

500W heater = roughly 5p an hour but as DD says it does not run continuously. Be aware however that you can buy a drimaster heat unit cheaper than you can buy a heater for a drimaster unit. I paid around £280 for my unit & they were quoting me around £400 to add a heater to a drimaster 2000 (which I was considering).

On another note, what is likely to be the colder surface. Windows or the external walls in my built in wardrobes (The air temp is around 4 degrees colder than the room air temp) ? & would it be the case that because I am now almost condensation free on my windows that I should not have to worry about mould returning in these wardrobes (currently free of mould for around the last 3 months).
Cheers.

OH no... I have just agreed to the drimaster 2000 being fitted. I did not know anything about a heater being added. I am now thinking its going to make our bungalow too cold??? What are these heaters then?

marshallka

2Sheds wrote: »

Hi
Thinking of adding the heat option to my drimaster, as I'm not keen on the cold air blowing downstairs into our open plan lounge. We still get some condensation too, unless the Drimaster is set to 5.
Only thing I'm concerned about is the cost of running the heater, as it would be running constantly in real cold weather. Do you know the costs of running the heater?
Ta

I thought the drimaster 2000 had a heater. Is this the 2000 model you are thinking about here???

Drimaster 2000 is all about savings!
The Nuaire Drimaster 2000 comes with an integrated heater that will warm the incoming air in the colder months, which will also help save heating costs. As well as saving money during the colder winter months it will also save you money during the warmer summer months, as the unit will go on standby automatically when the temperature in the loft exceeds 27 degrees so it wont constantly be running which will save money on electricity use.

dampdaveski

marshallka wrote: »

OH no... I have just agreed to the drimaster 2000 being fitted. I did not know anything about a heater being added. I am now thinking its going to make our bungalow too cold??? What are these heaters then?

Hi marsh,
the Dri 2000 has 6 speed settings so it's likely there will be a setting that you can use that will control the condensation AND not be high enough to make your house too cold.
you should be aware that it is quite normal when the weather is cold that your hallway will potentially feel cooler, A heater can be retro fitted to the Drimasters if it is too uncomfortable.
I have a Dri 2000 in my house and when it's mega cold I notice it BUT it doesn't affect the heating in any of the rooms.
hope this sets your minhd at rest:D
DD