As I improve air tightness in the house I’m starting to see more humidity problems (which is perversely quite satisfying). There have always been some issues but they are starting to get noticeably worse. I’d love to put in a whole house system, but retrofitting the ducting is I think a step too far both from disturbance and cost issues.

My initial concern is the main bedroom which sits above a double garage. I have been squeegeeing the windows most of the winter and I’m starting to get fed up with the early morning ritual and also concerned at potential problems due to the high humidity. My thought is to install a single room unit in the ensuite and hope that this will also reduce humidity in the bedroom. Some of the threads I have read appear to suggest that this might happen and I wonder if anyone who has installed one could comment? The bedroom is of course a far bigger area than the ensuite, but since I hate noise at night I don’t think I could put up with a unit in the bedroom.

I don’t understand how the in and out air is separated, but was wondering if creating an additional air path between the rooms would help? Assume door to ensuite open when not in use then would a “return path” from the bedroom via additional ducting help. This would be easy to do without any major disturbance as shower backs on to bedroom cupboard and holes could easily be created.

Should I be looking for an unbalance system to force more air movement? The 2 rooms are as far as I know devoid of major leaks but I don’t know how air-tight they really are yet.

Andy

Any ensuite fan should reduce condensation by getting rid of moist air at source , problem might well be warm moist air heading to colder bedroom and ensuite fan not able to deal with volume. fitting something similar to above will help reverse this air flow to bedroom to ensuite.

Thanks for advice. If I go for something like this do I need to worry about building control/regs? Clearly its not a whole house solution. I agree with the humidity control activation, but would also like to prevent it going into boost mode at night.

Yes I did see this, but couldn't actually see a price? Does it fit into the outside wall?

If i get round to switching it you can have my HR100 for £50

Posted By: andyman99I agree with the humidity control activation, but would also like to prevent it going into boost mode at night.

Humidistat control is the only way to go. Tbh, your major sources of moisture are going to be showers and cooking, so unless you're doing either of those at night you shouldn't have to worry about it running too much in the wee hours.

Where you might get problems is in spring/autumn, when it's chilly but reasonably damp outside. In these conditions you can get stuck with a unit permanently in boost, as the outside air it's bringing in isn't dry enough to cope. Your options there are to either adjust the humidistat upwards or just switch the thing off.

andyman99, if you need fresh air then you should of course be removing the stale air, and if you do that, there's a very good arguement to take the heat energy from that stale air as you bring in fresh air. Obvious so far. The thing is, it doesn't really make sense to remove all the air repeatedly, and replace it with new air, just to get rid of the moisture in that air (and as it reabsobrs more moisture from wet walls etc).
It's regularly talked about on this forum, so surprised no one else chipped in (or maybe I missed it?) but a dehumifier could be a much better option for you. It can then be run in which ever room is either creating the moisture (bathrooms/kitchen more so), or where the condesation is forming, which again could be various rooms.
I have one myself for clothes drying (another use for yours should you get one), and have a number of clients who rave about theirs since I recommended it for their cond'n problems. Of all the recommendations I make to clients, this has the biggest effect for the least cost. You might consider this one ....Ebac Amazon15...about £160 from "appliancesdirect" - best price I found.

greenpaddy, got a ebac power dry rigged up to solar Pv dump in my place but still struggle with heavy condensation on 2G windows on north side. Just to many people living and breathing in a small volume me thinks. Could always just open some windows a bit more !

Well we do have a de-humidifier (Ruby Dry) which, when it is used, is for drying clothes in a small utility room. I have tried this in the bedroom and it does help, but it uses around 350 watts on its medium setting. I suppose it does give off some heat too, but since it needs to be run for 2 to 3 hours to have a noticeable effect I’m reluctant to see it as a permanent solution?

TBH I am not too worried about the ensuite itself, we are mostly just 2 in the house and we will open the window for a bit after the shower to help the fan extract. When it is just us we are quite careful with anything that generates humidity as we have had to replace quite a few curtains over the years. Likewise air quality seems mostly OK and we can leave the bedroom door open unless we have visitors or returning oiks.

As the room is above a double garage it is quiet large and does tend to cool down overnight. Typically it will be 14/15 degrees in the morning even with the hole plugging and insulation that I’ve done, so possibly that is part of the problem. If outside temperature is below 4/5 degrees then the condensation is more than just misting (which I can live with.)

I can see the FiWi might work well downstairs as this is quite open-plan, but not where it would go upstairs such that it would work everywhere. But it does sound a great solution, can you just knock out some bricks and put it in, or do you need some sort of support?

Anyone know when building inspectors get interested? Presumably a simple through the wall bathroom unit is of no concern, but a whole house system might be.

A simple ensuite unit would be the easiest, but if it doesn’t sort the bedroom, then its wasted money. A bigger ducted unit would have more chance of working, more cost but greater flexibility in trying different arrangements. Hmmm I need a 3 sided coin.

Posted By: jamesingram
From an unscientific point of view, input/output seems all a bit too close together for me.

Yep, a fundamental limitation of the through-wall units. I'd imagine the location in the room would affect performance quite a bit. I've got one mounted in the corner of my bathroom, but it's the only place I could put it. Can't imagine the air mixes very smoothly, but it does the job.

If it was me Andy and to save all that expensive for x1 room, i would buy a domestic dehumidifer and use that in your room. £100 should cover it and save all that upheavel with ducting installation etc (just finished installing my mvhr system).
Scott