Craig88

Do you have an estimate of what this would cost? I received a quote from a company for £15k! That’s just for the 2 bedrooms, living room and hallway. So excluding the kitchen and bathroom. The entire apartment is only about 50m2 or so. Granted the cupboard doors would need to be removed and cut off so they don’t hit the roof. Seems it might be worth it to just heat it up/cool it down more via electricity instead as that payback period would be many many years.

Something like this? https://www.british-gypsum.com/white-book-system-selector/systems-overview/floors-and-ceilings/gyplyner-universal-ceiling?tab0=0

Do you have a link for what that is? I’m assuming you mean gypsum wood with a typical grid system? thanks

Thanks, sorry should have mentioned that. Current ceiling height is 2.65 so there is some scope for dropping it down.

Hi, I live in a 1930s top floor apartment with a flat roof above me. I’ve been considering getting new double glazing but I think my main issue is the roof is really poorly insulated which means the apartment gets freezing in winter and boiling in summer(31c at 1am and 26c at 7am). Is there a specific type that works best for residential? My brief searching seems to be that it’s mostly meant for commercial use and would make my apartment look a bit office like. Not sure if battening some type of lightweight insulation board against the roof and plastering over it would be a better solution? thanks

It’s a potterton suprima 30. Not really sure what the various measurements are but seems to be an output of 8.8 at max pressure. The three rads I have now are the old fashioned cast iron double column ones. Living room is 110x50, main bedroom is 160x75 and bedroom 2 is 90x90, which struggles to heat the room to 20 in current lower single digits. I’ve emailed a few of the smaller mvhr unit manufacturers like blauberg and they all seem to say they don’t recommend using 100mm ducting. I did think it might be fine provided I didn’t use it on boost although might invalidate the warranty. I meant the unit now has a trickle speed of 30m3/hr extraction rate which is currently split so the bedroom is getting air extracted at the rate of 15m3/hr. And even then it still gets condensation and mould build up. It does seem like a heating upgrade would be the best way to go about it. Considering if I was extracting from the bathroom now the temperature in there is only 16 so would be feeding 12c into the rooms with a lower end mvhr unit. I had considered getting a single room recovery unit. My only concern that having one in the bathroom and bedroom 2 would cost around 800 installed and there would be no ventilation improvement in the living room or bedroom 1 as they’d be in a vacuum. Whereas trickle vents in all rooms and one extraction point in bathroom would create a constant airflow in all rooms.

I’ve actually requested a thermal imaging camera from octopus now to actually see where the weak spots in my insulation are. I did initially think it was the ceiling but after getting secondary glazing in the main bedroom I realized that room would heat to 23 when outside temperatures were around 8-10 which didn’t seem too bad. I was also able to heat the living room up to about 22 last night with outside temperatures around 1, when using an electric oil rad heater. Usually this room would be limited to 18/19 at the warmest. Which makes me think I need another rad in there, although not sure if the current boiler can handle that as it already struggles to heat them all up if they’re open. The issue with the current mvhr is that it’s really old and noisy on boost. Which was why I was thinking of upgrading it and then ducting to the bathroom and main bedroom. But most units require 125mm ducting so it becomes a whole new installation. And for some reason or other even when it’s on trickle(15m3) all the time extracting from the second bedroom that room still has an RH of above 60% most of the time and a lot of condensation on the windowsills. So the end result is that I’d need to spend probably in the region of 1k-2k for a new system including additional ducting. And then the question is whether that’s worth it for the energy savings or just to get trickle vents on all windows and have one extractor in the bathroom causing air to come through all the rooms continuously at a low rate?

Thanks for the replies. Just to update it’s gas heating to three rads in the 2 bedrooms and living room. Living room rad is definitely undersized. Bathroom just has an electric towel rail heater which obviously doesn’t do much. The windows are actually double glazing, just appear old and misted along with drafts from the seals missing rubber etc. I had a quick look and the epc is currently 44 sitting in the E category. The report did recommend “flat roof or sloping ceiling insulation”. The bathroom does have a lowered wooden ceiling which might have been done to make it less cold. Just to give you an idea of costs for December gas was £74, which is nearly double November as the lodger has been wanting it warmer. Electricity £50. He sets the thermostat to 21 in his room but it never really hits that so it’s generally on all day. Obviously this is the extreme being that we are all home 24 hours a day now as opposed to last year where I’d have it come on in the morning for an hour or two and then again in the evening after work for 2/3 hours. The ceiling is about 2.65m high. I had thought about ceiling insulation but was just a bit concerned about the risks of creating damp up there which seems to be one of the side affects of internal wall insulation. I had emailed a few companies about the green homes grant for insulation but never heard back. The main bedroom is actually fairly warm and is often 23/24 when the other bedroom is around 21 during higher single digit temperatures. I think the secondary glazing does help with the that. Perhaps the middle ground is just getting the windows done, adding trickle vents to them, and adding another radiator in the living room. Along with a continuous trickle extractor fan in the bathroom. The current air brick is in the kitchen and the window in the kitchen has one of those round spinny air vents which turns when I put the bathroom extractor fan on so I know that’s where the fresh is coming from. The mvhr is currently extracting from the second bedroom and hallway. I can try switching it off and seeing if that improves the problem. I know all about dehumidifiers as I currently have two and would run them continuously last year, although found it pricey on electricity. Thanks again for the ideas.

Hi all, I keep coming back to this forum when researching mvhr so thought it would be a good idea to create an account and post a thread. I live in a 1930’s apartment block on the top floor with flat roofing, hence no loft. It’s a 2 bed 1 bath 55m2 square apartment with all the rooms basically off the same small hallway. It’s essentially not really airtight, there’s a big air brick in the kitchen above the boiler. Temperature wise it’s also cold. Now with London weather around the lower single digits(3c) the second bedroom struggles to get above 20c with heating on all day and the bathroom only has a towel rail and is probably 17c. Living room is 19c and main bedroom is 22c as it has secondary glazing, is south facing and has the biggest rad. The previous owners installed a kair trakmaster mvhr which is about 10 years old and doesn’t seem to be helping much. The second bedroom is quite humid and is constantly getting mould on the ceiling. I was thinking of upgrading it but it’s positioned in the second bedroom which means noise is an issue for the lodger in that room. The other issue is that they cored 100mm holes which means I’d ideally need to get the existing 4 holes cored to 125mm which is what it seems most units ducting size is the days. Which adds even more expense to the upgrade. I’m currently in the process of getting the windows replaced which is why I’m having to decide to either go for the passive ventilation option of having trickle vents installed and one continuous extractor fan in the bathroom or a new and better mvhr unit. I’m struggling to see if the cost of around 1,500-2,000 for unit and installation would ever pay itself back. My concern with passive ventilation is that it would make the cold apartment even colder if 2c air is constantly drifting into a room that struggles to stay above 18c when “airtight”. The other issue is that in summer it boils! Bedroom 1 will often be 30c at night and as it faces a busy road I have to keep the windows closed. Was thinking of getting acoustic trickle vents and having the bathroom fan on boost during summer might be one solution. any advice would be appreciated. Thanks