A Rated Door Glass

[dibsdiy]

I have had two new french doors fitted with side glass panels in my porchway, A rated glass all double glazed units. The porch is always open to an indoor room which has heating. I saw the damp course being fitted when the doors were fitted but I am now getting lots of moisture/condensation running down the walls directly beside these glass panels, both sides, left and right. It is so bad the carpet is now getting wet in the outer corners and even the sealant used at the sides is getting soggy. I cannot understand it as the old glass was rated C and I never had this problem before. Can anyone advise, is this an effect of the A rated glass and should I buy a dehumidifier? If so, the porchway is 13' x 2', can anyone advise the correct size and one that is quiet? Thank you for any help.

 

[ronniecabers]

Just to set the record straight , glass sealed units themselves aren't actually Energy rated ( even though many places sell them as such ) , it is the entire frame and sealed unit that gets the energy rating.
Back to your issue .. the uprated sealed units are doing their job, keeping the heat in and and this is by the argon gas and low e glass keeping the unit warmer thus the water vapour being held in the air in your house no longer condensing on the glass, however it is now condensing on the next coldest surface, which appears to be your walls. Yes a dehumidifier would help reduce this... purge ventilation or a PIV system might help too

 

[dibsdiy]

Thank you for replying, I am always interested to learn how different things work and was therefore very interested to learn about the sealed units. There is a tiny bit of condensation on the bottom of the glass in the mornings now, but not as much as with the old units. There is damp on and under the carpet and underlay in the two corner areas, but I cannot really tell if this was there before or has just suddenly appeared, my sense is it was not there before, it is too wet and the cement in the corners is a much darker colour. They had to put a cement base down for the frame to go on. Can you tell me what a purge ventilation or PIV system is?

 

[ronniecabers]

Purge ventilation is simple things like opening doors and windows , and the use of extractor fans
PIV - Positive Input Ventilation System, it pulls air in through the loft and pushes out through a machine in the loft

 

[dibsdiy]

Thank you again for your latest reply. I do have two small top windows either side of the doors, one of which is usually open but not at night. I understand the PIV, as a bathroom window was not being opened and steam was caused a damp problem there, in fact steam/damp managed to get in the pull cord ceiling fitting which tripped the electrics out which I wasn't too pleased about. I had a fan fitted in the ceiling which automatically comes on and is vented through an outside wall, I think they said something like a trunk fitting, but I didn't realise this is called a PIV. I think I will go for a dehumidifier and hopefully this will improve it. Many thanks for all your help, it is much appreciated.

 

[ronniecabers]

Your bathroom vent isn't PIV , that's just an extractor fan. A PIV system draws air from the loft ...