Beckside

I installed our MVHR and also created a void like you are by proposing to run the ducts. Then installed the valves on the newly created ceiling.

The vehicle that uses it is over four tons. Plus we had to have two trucks to deliver as one was not enough. So the excess was used where the heavy vehicle travels.

I have just had 160m2 laid in Ambleside. We installed all the edging and drains, and the hardcore base. We had 120mm on the bits that vehicles travel on, and 60-80 on the pathways. Having the prep spot on saves a lot of time. We also marked all the levels and falls on the edgings. I waited a week for a site visit and two weeks after that to have it laid. Can forward his details if you want?

Viessman on WC can still have a room influence if required. As has been stated, if you are well insulated and airtight, your whole house will have a fairly even temp, first floor circa 1,1.5deg higher than GF. Yes UFH in a screed is slow to react, but that is a benefit when in weather comp. The whole theory is gradual change, not on/off. You do not set the flow temps, the boiler does. Ours has never supplied higher than 29deg C to the ufh. You can set a legionella heating cycle from the boiler/app. Yes you can have multiple temps and times, yes you can have nighttime setback. Yes you can set an outdoor temp at which the whole system shuts off. There are a lot of variables you can adjust, once set up you shouldn’t have to touch it again, that is the beauty of it. Why would you want a wood burner if you have a correctly sized/set up, UFH? our cylinder is 300l, we have three beds and four showers and a bath. The tank is that size as we May holiday rent the place, and if six people come back after a day on the fells and all want a shower in quick succession then that is what I figured we needed. Our system has been in over a year and works exactly as expected.

Don’t necessarily need any stats, run it on weather compensation, where you have an outdoor temp sensor, then the flow temp is adjusted to suit. Defo treat the whole ground floor as one zone. We fittedsmall rads upstairs and have never used them. You will need good insulation and even better air tightness level to reap the benefits of low temp heating via Ashp. Spend the money on improving your designs to iron out cold bridges, and draw up all the junction details and ensure they are followed exactly. Junctions like where windows meet the walls, roof to wall, wall to foundations etc. you will need an architect switched on tonpassiv style approach or do it yourself. Same with keeping an eye on all contractors. We ended up doing almost everything ourselves to ensure we got the quality and a end result we wanted. Hopefully you only build once, so fabric first. If I was building again I would build to Passivhaus standards, you won’t need any heating input if you keep the details and materials correct.

There are not many boilers that modulatevas low as the Viessman. We fitted a W200, the big advantage is all the controls inc Wi-Fi are built into the boiler as std. it has a colour touchscreen and an app on a phone. Just the outside temp sensor, cylinder temp sensor and low loss header sensor to connect. Plus the Divicons if you go that route. If you do, you can buy indentical units to the Viessman Divicons for substantially less, they are very common in Europe so a lot cheaper. Join/ have a look at ‘heating system design’ a Facebook group, lots of info on people using Divicons etc. I really struggled to find anyone that even knew what weather comp and Divicons are, let alone the knowledge to install them. I used a guy from Southport, defo not the cheapest but very good install, and a 12 year warranty on the boiler, subject to a yearly service. Which over 13 yrs would buy a new boiler. We installed the ufh ourselves @150mm centres. Highest temp I have seen going in was 29deg c when it was -2 outside. Boiler is always condensing unless heating the tank. We have very small rads upstairs but never been turned on other to commission them. Have dual towel rails in each bedroom, electric side controlled by a Heatmiser switch, they are only 300w but work well.

We went low loss header and divicons with a Viessman W200 system boiler on weather comp, so no thermostats just one outside temp sensor, and a300l UVC. We have UFH on the ground floor and small rads and towel rails upstairs It was the ability to run two or three showers simultaneously that made the choice for us with regard to the tank. The divicons are not cheap but the system works really well. You would not need pumpsets on the ufh manifolds or any thermostats or actuators of you treat each floor as a zone. We were going to use wunda and Heatmiser as thought we wanted/needed that level of control. In reality if your house is airtight enough to warrant MVHR then you could treat each floor as a zone. It works really well

Sorry to say I agree with the OP, when I wanted to use weather comp and no mixers on the manifolds for my UFH. It was virtually impossible to find an ‘heating engineer ‘ that had even heard of it let alone had experience of this type of set up. I spoke to a lot of companies and consultants and not one had any knowledge or real life experience of utilising weather comp controlled heating systems. Yet this has been common practice in continental Europe for several decades. We are literally decades behind on integrated heating/cooling systems and their efficient control. I used a Viessman W200 system boiler which can control two mixed and one unmixed heating circuit. All software resident on the boiler with touchscreen and Wi-Fi connectivity. It controls to motorised mixing valves to control flow temps to the ufh based on outside temp. No internal thermostats, it works incredibly well. I think you have worked out what to do, find another ME with low energy experience.

I have four bathrooms all with WC, shower, sink and one with a bath. I have one 110 AAV in a roof void. The only penetration through the fabric of the building above dpc is for the boiler flue. We are on a septic tank not the mains. It all works fine at the moment.

Before we rebuilt and now have a new kitchen I fitted an external motor for an existing hood. It was Weston in West Yorkshire that supplied the exterior motor complete with remote control. I was going to add a humidistat in the hood to trigger the motor but never got round to it. They also do custom hoods

Hi Tony K We fitted a Bora hob in the end, but nearly bought a Novy Panorama, the Novy range is good quality, not cheap though. if we have 3 pans simmering and a fry pan going then we have to run the extract on its highest setting to capture probably 90% of steam. The MVHR picks up the rest. We have found that the ovens can create more odours as they vent to the front. On the whole though we don’t seem to suffer from odours. One mildly annoying side effect is the Bora vents out into the void in the centre of the kitchen island, and then grilles around the plinths, so you can feel the draft on your legs, but only on the highest setting, which to be fair is not used that frequently. Anything that prevents more penetrations in the airtight layer, especially to outside has to be first consideration. Good luck with your build.

As Johnmo says, re circulation is generally the way when using MVHR. As the volume of air an extractor can move is way more than the mvhr, so upsets the balance. Plus you are removing warmed air. Any top end extraction system will have a grease trap or filter incorporated, re circulation or direct extract. I was sceptical about the re circulation, but with a years experience I can say it does work. We have an open plan kitchen, dining and living room, the living room is a vaulted ceiling. We have virtually no smells in the room, no matter what we cook or how we cook. I have seen in most European countries, if they fit direct extract with mvhr, they have a motorised valve to close off the extract duct when not in use. Also as I said it is one less penetration of your roof membrane.As I said we fitted a Bora downdraft extractor, as we did not want anything above the hob, as it sits on an island in the middle of the room.

If you are building with high insulation levels and good air tightness then a re circulation extraction system would be better. As you are extracting warm air from your house. We fitted a Bora hob and downdraught extract on re circulation and it works a treat. Also you do not need to make a hole in your mew roof membrane

I used a Renson Enduro Delta 380 unit and also used 90mm semi rigid ducting. I ran double ducts to a single outlet in kitchen and utility. 13 extracts and 13 supply. It has built in humidity, c02 and particle sensors, no need for any manual boost buttons. We cannot hear it unless on the highest setting, level 4, which it has never actually used. It moves to level 3 circa 60 secs after turning on a shower. I used 180mm dis eps ducts from the unit to outside, and to the distribution plenums. Used HB+ ducts and boxes, Renson supply and extract outlets. The Renson unit is app controlled, but only when in range of the Wi-Fi it is connected to.

Not sure what you mean by a 300mm upstand. I fitted four 3G velux in our warm roof, used the Std flashing kits for a slate roof. Fitted extra insulation around the frames. Been in over a year with no problems. 3G is much quieter than the 2g versions