dogman

So its been a few weeks since I posted an update. Frame is 90% battened and sealed. MBC left as windows and doors had not been fitted. Roof is finished including gutters fascias and soffits etc. The windows and doors are a different matter. Its been and still is a bit stressful. Don't want to say much as it is still ongoing. Do have a couple of pics. Hopefully we will make some progress with the windows and doors next week. As you can see with the sliding doors there is no glass fitted so house is not secure. As we have night time visitors i dont want to order in equipment until it is.

I would have thought that being a min of 500mm from wall and that there is not a great deal of combustible material in a heat pump means they are low risk.

I was impressed with the inside of the Dewalt. Metal gears in a solid gearbox. And easy to take apart

One of my Dewalts blew up last week doing the same thing. Swapped to a 240v drill and it was like going through butter. Me being me took drill apart and found there was a plastic coating around the metal coils that had disintegrated. Cleaned it out and it works again.

Not in place yet. Am having a nightmare with the windows so everything has stopped. The plan is to fit them, so there is a hole in floor , test them, drain the pipes and leave them in place. If house is either hot or cold i will buy the units and fit them. Remember fan coils also need power.

I found 15mm that are in a sort of fitting. However you can just use a 22mm to 3/4inch elbow Hep20 do a plastic one. They did do a brass version if you can find them still. eBay link

Anyone with a BPC system. Does the systems they supply use disks in the plenums or terminals or do they screw down the air valves. I have not yet got all ny equipment and would prefer to use a disc based system.

Many thanks everyone. As @Barney12 stated it was a HVAC engineer. I would rather go with practical experience rather than the engineers view. I suppose in his defence he was talking about the supply to the system being at 7 deg or less not 12 and above. Ill stick with my plan of cooling the slab with a small cooler in the MVHR supply to lower the air temp coming in a few deg. I am plumbing the house for fan coil rads in case i do need more cooling. Being a northerner my idea of heaven is 2 foot of snow and minus temperatures. Anything over 18 is far too hot for me.

I was speaking to an engineer today about cooling our house should it need it. He was talking about fan coils when i mentioned cooling the slab with underfloor heating. His advised me not to due to condensation and the risk to the floor and concrete. He stated that it was due to the dew point/humidity in the house and the condensation around the pipes and on the floor. He stated it would form not just on the floor surface but under tiles and around the pipes Now i don't pretend to know anything about this but i am sure that those who have looked into cooling a slab must have considered this issue and mitigated against condensation forming. Can anyone help with this issue(if it is one)

@Barney12 Is this the unit that BPC sell. What size did you get in relation to your house size?

I bought a SHARP Plasmacluster air purifier for our old house as it stank of rotting house. Not sure if its the same technology. In a small bedroom it certainly removed the smell and made it feel fresher. Often wondered if i could build it into the supply to the MVHR

Im an MBC client. Currently 90% finished. The advantage to me was they do the foundations to roof so need to worry about nothing till your windows go in.

Suggest you go and see some being built and or finished. Most companies will offer this and give an indication of the confidence they have in their builds. Ours is erected and waiting for the windows to go in on Thursday. Happy to show visitors around if you fancy a trip to Berkshire although there will be some closer.

I did a bit of an experiment yesterday with our Ecocent. Our room in roof gets very hot so i vented ecocent into the room for the day with windows closed and covered. The room was kept at about 18 deg while the other rooms were 26-27. Our ecocent comes on when the water differential between top and bottom is 15deg so as JSH suggested it runs for 4-5 hours a day in total. The issue re venting as dpmiller states with out a vent you are pumping into a sealed space. You have to vent somewhere. As you are extracting warm air from the house with the ecocent you need to return an equal amount of air to the house,If the house is airtight this will need to be from the larder. You cannot vent outside as you will then need a vent into the house to equal the pressure. As the Ecocent only runs for an hour or so at a time the impact on the heat in the rest of the house will be minimal. If the vents are in the right place all you will be doing is pushing the warm air out. None of this has been boffin proofed it is just my simple thinking.

One idea i had was to use a Ecocent for the hot water. It can extract from a hot area in the house and the cold 6-7 deg air will be vented into the larder. If insulated it will cool the space enough. Downside will that you need a vent into the heated space from the larder and in the winter it may cool the location of the larder ie kitchen

Had MBC on site again today. Having finished the MVHR pipe work they wanted to install the membrane and battens inside We now have 2 very angry swallows who need to find a new roost. At least they didn't get chance to build a nest

I never thought about the potable aspect will need to check. However i was thinking of using the feed to the hot tank / sunamp / or whatever fit as a sort of pre heat. however it would be intermittent or feed from heat pump in summer which will be used for cooling.the slab or as we initially were going to do was use an ecocent and use the cold air produced to cool the larder. I would then vent the cold flow out of the larder to the back of the larder fridge to help keep it cool

We will have a walk in larder with a MBC twin wall house. https://www.bpcventilation.com/water-cooler-battery I intend to fit one of these to cool the room however it will need to vent into the house unless you remove the room from the airtight area of the house Although things are evolving in our design and there are other options we are looking at

Our council ( West Berks ) took a slightly different approach. There are several exemptions one being self build, and another being replacement dwelling. We filled in the forms but the council returned them as not required as we were exempt due it being a replacement dwelling with the same number of bedrooms. The planners confirmed this in writing stating that self build exemption only kicked in if another exemption did not apply. Apparently its more work for them to do the self build as they have to charge you the CIL and then exempt you from it.

Spent the afternoon playing with my big red snake Had to get wife to help by pulling it. Got a big problem with swallows. The birds that is. Decided they like the house and want to move in

Thanks @TerryE the standard detail on MBC show the DPC lapping over the DPC on the ring beam. However over half the brickwork will be under ground due different levels. This means a second DPC will be needed at FFL. I will probably fold it down and pin to slab, to keep cavity clear and have a DPC at FFL.

I needed to run a length of radial through the airtight wall and didn't want to run a 100mm duct as a sleeve. For those looking to do the same 80mm downpipe from floplas is a perfect fit

Mbc fitted wide DPM on the soleplates. The flap has ended sticking out about 300mm On the rendered section it will be folded down and covered as others have done. What do i do where there is brickwork. There are 5 courses of bricks under the FFL off a ring beam. I have seen it on some pictures folded down 1 course into the outer skin to form a sort of cavity tray. Others just folded down into the cavity. I have to install weep vents every 1.8m at the base and above any cavity trays according to MBC but i forgot to ask about the DPC Anyone know the correct way to deal with it?

Looking good, Have you put joints at slab level for those SVPs so you can connect at floor level if needed. saves digging out the slab later

we skipped quite a lot but kept anything usable. mbc did say they would take any whole sheets and corners. I suspect that between all the builds on here there is enough waste to build a decent sized house base.