MikeGrahamT21

Looking at the bare side, to me it looks like wood fibre board, its entirely possible though the texture on the other side could be artex which could contain asbestos, get a test done and you'll know for sure

Any photos of the other side of the board? (Loft side)

So after around a week with the new fan speeds, it’s got the exhaust value down a couple of degrees without changing the supply temperature so that’s good, but the supply is still warmer than the extract. decided to get the thermal camera on it and it gives a similar reading extract pipe supply pipe observe the centre value as this was pointed at the plastic PVC pipe which is same on both and not reflective

I think you were right! Revisited this today. When i originally balanced it using the loan anemometer, was middle of summer, super dry and I’d just installed brand new filters into the Cleanbox which clearly had a much lower pressure drop compared to middle of winter when they’ll be holding a bit of moisture too. The figures i put up above i got wrong, they were 35% extract and 36% intake at normal speed. Got the specs up of both units and ran it all through Gemini which gave me figures of 42% intake with 35% extract at normal speed, and 59% intake with 50% extract at boost to compensate for the pressure drop. I’ve knocked a couple of % off of the normal extract speed in order to get the intake down to 39%, which suited the extract being at 32% apparently. I suppose this would be where a constant volume unit would come in handy which would sort itself out. So yeah, thanks for seeding the idea, I’ll keep an eye on temps etc and see if that cures it, I clearly didn’t leave it long enough the other day when i was messing

For clarification for my unit: Ext - External - Temperature of the fresh air coming into the system Exh - Exhaust - Temperature of the stale air once it has passed through the heat exchanger Int - Internal - Temperature of the stale air coming into the system before heat exchanger My unit doesn't have a supply temperature sensor, which is why i added some of my own, but they were only cheapy

Out of curiosity earlier I changed the fan speeds to 40% intake and 30% exhaust and it made absolutely no difference at all, temperature stayed identical on all including the controller of the MVHR, I left it that way for a good two hours as well, have put it back to how it was previously now. still curious as to what other peoples MVHRs are showing temperature wise for comparison?

I balanced it all last year and got both extract and supply at the same overall values, so should be fine on that front, and the fan speed is set to the same, 35% normal and 50% boost

No heaters in situ and like I said I’ve swapped the thermometers around and the error always stays the same, yes they are defo labelled correctly, have checked a million times myself months. They are only cheap thermometers agreed, so how about the readings from the unit itself, do they seem right? I’ve just nothing to compare against and this is the only MVHR I’ve ever owned.

Hi This has been bugging me for a while, but I’m still not sure if anything is wrong as I’ve nothing really to compare it to, but one thing stands out as odd, and defying physics. So MVHR system has been in around 4 years now, set the valves up last year. Unit is a Vortice HR200BP serving a small 79m2 bungalow, with all of the radial ducting in the loft under heaps of insulation. The inlet and exhaust ducts are preformed polystyrene type with a small amount of flexible ducting where needed, so as to create as little pressure drop as possible, and there is also a Blauberg Cleanbox 125 on the inlet, with G4, H16 and Carbon filtration in there. Couple of years back i bought some cheap temperature sensors off amazon just out of curiousity, as although the unit has its own temperature readings, they don’t include the temperature going back into the property, only extract, inlet and exhaust. Now I’m sure for a long time everything seemed feasible temperature wise, the extract was around the temperature of the bungalow, and the supply was slightly lower as you’d expect, some small losses. Now it’s constantly higher than the extract, which is obviously not possible, there is no magic heater or anything in the ducting. You’re probably thinking, just cheap sensors that aren’t reading right, i thought so too, so i swapped the supply and extract ones round and the ‘bad’ reading followed (and yes I relocated them on the wall correctly too! lol). Yesterday I had the unit all apart and checked everything, cleaned the G3 filter which is has on its extract side, and washed the heat exchanger out (though to be honest, aside from dust on the filter, it all looks like brand new in there), and it this point i moved the sensor which I had on the intake, to the exhaust just to see what temperature it showed compared with the units own sensors, and I was surprised to see it showing 17C, with an outside temp of 9C currently. Now the units own sensors shows 14C as the exhaust temp, and the sensors are literally next to each other, but could just be the poor quality sensors again? My main concern is the fact the supply seems to be warmer than the extract?! The air coming out of the ceiling valves using an IR thermometer shows between 18.8 and 19.5C depending on how far the pipe run is, which seems feasible. Does this all look OK compared with your units? Thanks in advance!

Not directly related to building as I’ve never done anything during the winter with my place being a renovation, but I’ve always struggled in the darker months of the year, from my birthday in late October right through to the end of February. one thing which always perks me up is when things start to grow again, snowdrops, hellebores, crocus and followed by the other spring bulbs, you know better times are on the way. Appreciate the full on self builders won’t have much of a garden, but you can always have a walk round where you live. The dull days really don’t help, and this January has been the dullest my 10 year old solar panels have experienced so far!

Does the other pressure gauge also show pressure? Pump error sounds more like it could either have broken or have something lodged in it? Wherever your pump lives, it will have a screw (big) on the front of it which can be undone to remove any debris. Also make sure it has power and its at least trying to work. Example pump showing the screw

Places like B&Q and Wickes are actually quite good places to buy timber from, since their warehouses are also shops, they are heated to some extent and ventilated, but even there some of it can be warped, or just not dried enough as the tanalising happens after kiln drying (iirc), and often isn't left long enough to dry before being shipped to store

Roof Giant was who I used and had best prices. They all order direct from Velux so delivery wise it’s no different. Get the blinds from elsewhere though, others sell them at a huge discount

I used these on mine: https://www.wickes.co.uk/LoftLeg-Loft-Lid-Downlight-Protector-Hood/p/148851

Bleach doesn’t kill mould in any way it just hides it by bleaching the visible bits. Use proprietary mould killer to get rid of it permanently. Hope you had a mask on when you were sanding/scrubbing as it can end up in your lungs and cause aspergillosis, not pleasant at all. Ensure the boards are as dry as possible once treated, then sealing them will help reduce uptake of moisture, but be careful what you choose to use, as it could interact with the glue in the ply causing it to delaminate, I’m sure there will be a purpose made product for plywood sealing.