on 2 November 2014
I work in facilities management and HVAC for commercial buildings so I am used to dealing with large air handling units for office buildings and other complexes. I am aware therefore of how buildings have to provide fresh air for occupants. This is a simplified miniature version for the home. I bought the version with the heater option as it was cheaper to have it built in rather than buy it at a later stage. My main reason for purchase was for ventilation and fresh air because I live next the motorway so lots of noise and dust from traffic etc. I love fresh air also so my windows are constantly on the catch all the time but this means cold air just infiltrates the house but doesn't really ventilate. I don't have any damp issues other than the bathroom walls dripping with water after a shower. My house is a 2 bed small end terrace with 2 rooms down and 3 rooms up double glazing no trickle vents, cavity wall insulation and above the recommended loft insulation.
I had issues with cooking smells lingering and getting upstairs along with bathroom smells coming downstairs and the usual stale bedrooms on a morning, despite windows being left on the catch 24/7 it made no difference. The fan was installed by an electrician with the vent put into my landing ceiling. It was recommended for the size of my house that speed setting 2/3 was used but I couldn't feel much air flow from the vent. As I wanted to actually feel fresh air coming into the house the same way an open window I put it onto speed setting 4. I closed all the windows so the house is only relying on the Drimaster fan to ventilate and within half an hour the landing felt and smelt fresher with clean filtered cooler air coming in. My lodgers were cooking burgers and frying them in the pan that evening (I hate frying smells) and usually you can still smell this through the house the next morning especially the kitchen. Now the next morning there were no cooking smells at all, nothing unpleasant just fresh and aired. The house even felt warmer. Our kitchen is also feeling warmer and this is the coldest room in the house as there are cold draughts coming under the cabinets and around appliances.
What the fan does is filter air from the loft & pump it into the house from a central point (landing) which then pressurises the house. This is the same as what they do in operating theatres to ensure there is no dirty air penetrating into the theatre environment. Imagine a balloon with holes in it and your trying to keep it blown up. The balloon is the structure of the house and the holes represent the air gaps within the house such as cracks around doors under floors and air bricks that sort of thing. Normally outside air will penetrate these gaps which results in a cold house and that's how your house normally ventilates but inefficiently so. The fan is technically blowing the house up keeping a gentle pressure that is higher than outside so any stale damp air is pushed out through the gaps inside-outside. This means that the cold air that was coming in round cupboards and skirting boards in the kitchen are kept at bay. Any smells and humidity are constantly diluted down with the filtered, clean, fresh & dry air.
I'm amazed at how good the fan is at circulating the air. This is not a propeller fan like you would have on your desk (which would do nothing) it is a Centrifugal fan which are used to push air and create pressure in a space. If its 12C outside the temperature of my loft is 16C, I fitted a digital thermometer in the loft and one outside to compare... so instead of 12C dirty polluted air coming in through the windows I now have 16C air blowing into the house. Should the loft drop below 10c the small 500w heater will kick in and pulse on and off to increase the air temp up to 8C this is just for comfort of the occupants so you don’t feel icy cold air circulating on the landing and it’s there as an option should I decide to fit it on a timer so that the heater part only runs on a morning when people are getting ready or on an evening. We had a cold night last week where it was 4C outside and the loft was at 8c so the heater kicked in and the air blowing out was at 16C on the landing.
Yes it makes your landing a little cooler but if you want a fresh and dry home then there has to be compromise and nothing is free but this is the best and most efficient way of achieving it without expensive dehumidifiers. Even if your heating is on a bit longer this still nowhere near like the running costs of a dehumidifier which don't really help and cost a lot to run. Nothing can beat fresh filtered air and plus the air flow from it is warmer than it would be opening a window due to the loft being 4/5c above the outdoor temperature. You might as well reuse that heat that has escaped into the loft as even if you have the best possible insulation heat will still escape.
Hope this review helps people, don't hesitate in getting one I wish I had got one sooner. The house is less draughty especially on the landing & stairs where you could feel the cold air from the windows on the catches just sinking down the stairs. Anyone that has had poor luck with these you either need to adjust the fan speed higher or lower. If it’s too draughty turn the fan down or turn up if you are not getting the results you were expecting. Keep all windows closed as air will take the easiest route out of the house and that will be the windows. Leave internal doors ajar.
Any questions please ask :)
on 20 March 2015
Having gradually insulated, draught-proofed & added double glazing to an old house, you eventually get to the point where the moisture goes nowhere and settles on windows, cold walls and gets into the loft - sometimes raining down from the roof felt onto the insulation below.
So what do you do? Well you scratch your head and maybe like me you buy a dehumidifier to run for several hours a day during the colder months when you'd rather not open a window and let all the heat out. Great, you think - job done. Then the electricity bills come in and you notice that the cold walls are still damp and some rooms are still musty and you start to think there must be a better solution. Well there is!
It took a while for me to 'bite the bullet', knowing I'd be cutting a (22.5cm diameter) hole in my 1st floor ceiling. And then there were the options: standard, 2000, or heat? Having read reviews and looked at product information, I settled on the Drimaster 2000 - since it's intelligent enough to get back some heat from the loft when it can (when the heat from the sun might make the loft warmer than indoors), and I'd rather heat things using my radiators than a small electric coil in the main unit (gas is about a third of the price to heat with).
So, about an hour after starting to cut the hole I had the thing completely installed - including the sensor. It's very easy (the instructions are excellent) - just a bit messy as the plaster board dust gets everywhere. One thing to note is that whilst the visible white plastic ventilation outlet is square, the mounting holes are NOT symmetrically placed - meaning that if you mark where the holes are, fit the wall-plugs and then accidentally offer-up the outlet at a 90 degree offset, you get a bit of a shock and start to think how bad you are at DIY, since the holes no longer line up properly!
Having turned it on, with a speed of 5 (out of 6), you can easily feel quite a breeze coming through from the loft and you get the uneasy feeling about what an idiot you are. Why, after doing all the insulation improvements around the house, would you cut a hole in the ceiling and get cold air coming in? Whilst I'm sure my other half was thinking this, I was confident I'd done the right thing. (Fingers very firmly crossed.)
The next morning, the top-floor landing was a bit chilly to walk over, but the fresh air was nice. I said to not use the dehumidifier any more, and after everyone had showered (we have 5 kids between us) I was interested in seeing how quickly things dried up. Definitely more slowly than running the dehumidifier at full pelt, but far FAR cheaper and quieter.
A day later I was up early and the rooms that used to smell musty were improving. Three days later and I turned the fan down to 4 and still things dried up very nicely. A week later and it got turned down to 3. It's 2 weeks on now, and I'm tempted to turn it down to 2! At 3, you can just sense the fresh air coming in when standing beneath it, but it has made a HUGE difference to the house.
Let's go over the benefits:
1. Far cheaper to run than a dehumidifier.
2. Cheaper than opening windows (since the loft air is warmer than outside).
3. Incredibly quiet (you hang it via a cord from a loft rafter so no ceiling vibration occurs).
4. If you have musty rooms, the dampness and smell should go. Where I sit now, I'm next to a corner of a room that used to get very damp and musty. The furniture used to go grey with dampness and dust (and probably various fungi). No longer a problem! The air is fresh and healthy now.
5. Fresh air!! I cannot say how much of a difference this thing has made. A sealed house is very energy efficient, but probably very unhealthy.
6. No condensation, anywhere. In fact, this things 'treats' the whole house when the dehumidifier didn't. Quite surprising, but absolutely true.
7. Dry air is cheaper to heat than humid air - although I have no idea how much you'd save from this.
Are there any drawbacks? Sure:
1. You're bringing cold air into a warm house. But let's think about this for a moment. Cold loft air is coming in, so some other air has to escape - which according to the manufacturers is through gaps in window seals, cat flaps, etc. Quite right, I'm sure. But those gaps have always been there - letting in cold outside air, which is colder than the loft. So, which is better? On a cold windy night, those gaps were letting a lot of cold air in - whereas now there's a slow constant trickle of warm (moist) air leaving through those same gaps. So I'd say it's not as simple as just saying cold loft air is coming in, since it could effectively stop even colder air coming in from outside.
2. The colder air needs heating - so my gas bills will have gone up very slightly. Do I care? Heck no! My kids are breathing fresh air, the dampness has gone and my loft is dry! I have monitored the gas meter before & after, but it's difficult to say if there's much of a difference as outside temperatures have a huge effect on things.
Oh, and did I say my loft is dry? HUGE benefit. As I said, it used to RAIN in my loft, as the dampness used to accumulate (it's quite well sealed) and condense on the roof felt - falling down onto whatever was in the loft, sometimes including electrical junction boxes... This is NOT a selling point that's listed, but if you think about it the air that's pumped into your house from the loft has to come from somewhere, so effectively your loft gets the Drimaster treatment too as drier air is pulled in! Maybe this won't be true in all cases, but it is for me.
How about when it's damp outside? Well, having thought about it, and recently experienced a damp day outside, it's not a problem. Cold damp air enters the loft and is slightly dehumidified by whatever's in the loft (since it was previously a dry environment), and then enters the house where it warms up. Warm air can hold more moisture than cold air, so the relative humidity instantly drops. So you really don't notice.
Running costs? These days, something using 1W of electricity running constantly for a year costs about £1. Currently I'd guess the fan is using about 8W, so I'm not worried. Compare that to a 300W dehumidifier running for several hours a day.
Oh, and you get a 5 year warranty. Strange I'm putting that point last - since that would normally be one of the best things.
So, I am indeed very impressed, and surprised, at how well this has transformed our house. Highly recommend. This is the longest review I've ever written, which hopefully makes it clear how impressed I am.
Well done Nuaire!