Hi All,

I’m converting a bungalow with major renovation and a new roof. I’m installing several Velux windows upstairs as planning dictated I can’t have dormers.

Has anyone tried Velux Active home monitoring and ventilation? For those that don’t know it’s an add on to electric Velux windows. It comes with a sensor which monitors humidity, CO2 and Air Temperature and regulates them to your settings through the Velux. Apparently recovering up to 75% of the heat from the out going air in the process. It’s £180 odd for the first kit and then £70 odd for further rooms.

This price seems very reasonable and much cheaper and easier to install that all the ducting involved in other MVHR systems. I have ruled out ducted MVHR as my property isn’t being built with strict air tightness in mind and due to difficulty running the ducts with it being a bungalow conversion. I am however very interested in Aereco products.

Does anyone have Aereco house ventilation? If so what kit and how do you find it, is there a noticeable difference? I appreciate this Velux system would only do the bedrooms and the Aereco system does the whole house but for the cost it can’t be ignored..

Any help or thoughts much appreciated.

Tom.

I'm confused by the content on https://www.velux.com/products/ventilation/velux-smart-ventilation They say 'Fits most MK sizes of our top-operated roof windows'. What does that mean? I take it to mean top-hinged but there's a picture of a woman accessing the unit with the top of the window outside the frame? And the schematic of a man installing it seems to imply the sash has to be removed altogether?

I'm impressed by the low price, but I don't understand why subsequent units would be so much cheaper than the first?

Posted By: tonyAs far as I can see all the do is let (hot) air out in greater or lesser amounts.

The page I linked to explains the mechanism. It's the same idea as an enthalpy wheel, though less efficient. I've seen other devices using the same idea but I don't remember which.

I am very suspicious of wonderful graphics; a designer can draw any air-flow graphic that the client wants.

As far as I understand things, MVHR is designed to provide a cross-flow of air in a room. Surely this will only supply / extract air in a very limited space and most of the room will not benefit from fresh air as eddy currents will establish.

Additionally, I assume that this require power. How many roof lights have a power source close by?

Posted By: RexAs far as I understand things, MVHR is designed to provide a cross-flow of air in a room. Surely this will only supply / extract air in a very limited space and most of the room will not benefit from fresh air as eddy currents will establish.

That's how things like Fresh-R work though, isn't it? and they seem to get by. I suppose there's more mixing with the rest of the air inside takes place than we expect.

Additionally, I assume that this require power. How many roof lights have a power source close by?

Is it not solar-powered?

Posted By: GreenPaddyBUT...an MVHR outside of the thermal envelope? Do we take the over 75% heat recovery at face value? What's the cost per unit? What are the flow rates?

I worry about the outside location as well, but I suppose we just have to trust they've insulated it sensibly. Ditto with the 75% claim; it's not outrageous, since the best units claim over 90%, but Velux would be staking their good name if they don't have any evidence. I didn't immediately see a cert on the website though.

TBH, the web page looks like a pre-announcement (aka vapourware). Trying to find it in the shop seems to be impossible. There don't seem to be any documentation links, nor customer references etc. It's all a bit new.

I’ve spoken with Velux about this product. I think the figure of 75% heat recovery is disingenuous at beat. It seems there isn’t a heat exchanger of any sort. It’s just an automatic window opener and closer, but it won’t allow the window to open if the outside air temp is below a pre set temp. This is how they claim heat is recovered within the system.

I asked what would happen for three quarters of the year at night when the outside air temp is below what most would desire in the bedroom if the C02 levels become high? Answer - The window stays shut. Same for humidity. So basically nothing happens. I asked if I could do without a bathroom extractor if I had one of these in a bathroom Velux and the answer was no, for the above reason that it wouldn’t be practical.

It can open a vent instead of the whole window at times but this is basically just a trickle vent so without any sort of fan to assist it could take a while to clear the air from a room.

Hope this helps someone considering this. I may have understood the system wrong so do double check yourself.

I’ve spoken with Velux again and it would seem it was a bit of both. The product isn't for sale in the UK, yet it is on their website. So the sales team only know what it says on the website and no more.

They can however take your order for it. Prices are for the 780mm frame size £644, 942mm £643 and for 1140mm £702 all plus vat.

Difficult to buy when they can’t answer any questions on it at this stage. You’d have to get In touch with Velux in a mainland European country which sell it to get technical (or even fairly basic) answers.