Triassic

I was at a 'Do' at the village hall at the weekend, I was introduced as "the bloke who made at that noise last winter". Apparently, as an incomer, I need to live in the village for at least 3 generations before I'm from round here!

One of the MVHR units suggestions by BPV is the Domus HRX-2D. Has anyone used it, are they any good?

The Timber Frame company arrived on site on a very wet mid-January morning. Very quickly wagon loads of components started to arrive and before long every space around the slab and up the drive was dotted with Ikea style flat packs, assorted timber and steelwork. The first job was to floor out over the basement to form a flat working platform for the main house erection. The original specification called for pre-stressed concrete floor panels, these were changed to Posi-joist, as this gave us space within the joist to locate services, ducting, electrics and waste etc. With the basement floor in place, the sole plate was positioned, levelled and fixed ready to attach the wall panels. With every panel, piece of timber, beam and noggin precut in the factory and numbered and with a full set of drawings, the house started to take shape quickly. Four weeks later and the roof timbers were in place and the next job is to fit the roof.

In all the time I've been a member of Buildhub it's all been talk, now things are getting very real, the walls are up and the roof starts going on tommorrow. We have various window quotes, which we've reviewed and decided on which manufacturers windows range best suits the house, we've also finalised the internal and external colour. My next task is to talk prices with them and see what flexibility there is. Is there any particular strategy should be using in my negotiation.

I agree with Jeremy, Paul’s set up is not Micky Mouse, to the extent that he has to have heat dumps in his workshop to dump the excess generation. He has a backup generator that he only ever runs when he’s welding!

That’s the bit I’m struggling with, I don’t have an accessible 4m wall. The wall adjacent to the unit is in a sheltered, South facing position, but only about 3m in length. To get them spaced at 4m or more, I’d have to have the inlet on adjacent walls, but still in the sheltered position.

Looking back some old quotes (for around 2 years ago, our old house took longer to sell, hence the delay) BPC had quoted for a system based on one of these. I recently asked them to update their quote and they came back with a quote specifying two smaller Vent Axia units, not sure why? I’ll take a look at the high flow unit, as it’s the sort of thing I had in mind.

All the quotes I have specify 2 MVHR units, having looked on line, the majority of units are for homes up to 150m2 floor area. As I have a large plant room and wondered, is there anyone manufacturing a large capacity single unit ?

Can’t you simply ask for a free smart meter?

We had the same problem on a Scout campsite, 1.5km - 50mm alkathene pumping main. We used a portable fire pump to blast the crap out of the pipe.! We purchased a 50mm alkathene to 1 inch BSP fittiing and connected this to the pipeline and the pump. The fitting cost around £6.50 on eBay. Mains pressure might be good enough. Plan B would be to purchase a 60m roll of the cheapest 15mm pipe you can find and use that to rod the 50mm pipe. If it were me I’d connect one end to the mains and flush and rod in one go. Wear appropriate PPE.

I’ve just read that some energy companies are introducing Electric Vehicle tariffs, you get 60 to 70% cheaper electricity during the night. Apparently some Sunamp users have switch to the tariff to save money. I think @AndyT might have more details

Having never used the stuff before, am I buying 100g or 1kg?

According to the article Oxalic Acid is the stuff I need to clean the black marks. Apparently these are caused by contact with ferrous metal, fork truck forks, tools, metal banding etc. Now where to buy Oxalic Acid?

I think part of my problem is the orientation of the posi- joists, especially around the landing area, I’ve ended up with a few solid timber trimmers in the way!

Our beams have the rough saw marks on them, which we’d like to keep. I was thinking more along the lines of spray on type cleaning products, that would remove the black marks, without having to remove the wood.

Pity your not local to me, I’d have taken your muck away as cover for my site.

When planning the MVHR system I’ve visulised the duct runs and checked the architects drawings to make sure what I had in mind was doable. What I’d not considered was how the timber frame is constructed, it has loads more, and chunkier, timber than the previous house, lots of structural timber elements etc, all making it more difficult to run ductwork.

The timber frame is up and the roof is going on. The first roof elements are a couple of oak trusses and oak purlin, these have various black marks on them. Can anyone recommend the best method for cleaning them up?

These things are a real pain in the bum! We have a rental,property and the deeds say we have a right of way for taking coal in and rubbish out. The neighbour is there in your face if you dare to take a bike or a box or building materials via that route. He’s adimant they’re not covered by the right of way and won’t let us pass.

@mvincentd thanks for sharing, it’s good to see an alternative solution.

So having reworked the figures and based on a total floor area of 388m2 x 0.3 ACH the whole house ventilation rate is 116 l/s . It's starting to look like a very large MVHR system with lots of pipes!

Ah right.. The total internal floor area of the house (every room, over all three floors = 388m2 So 388 x 0.3 = 116 l/s So having reworked the calculations to us 75mm pipe throughout and use more pipes to reduce the velocity, the total flow rate / hour= 75. If I understanding this correctly I need to extract an additional 41l/s to get the rate up to 116 l/s?

@JSHarris Thanks for the feedback, just a couple of questions.. The 0.3 l/s per m² - is this the internal floor area of the rooms being subject to ventilation or the whole house floor area? Could you clarify where the 177 figure comes from?

Can someone sanity check my calculations? Where do I go from here? I've split the kitchen, so it has 2 Extract and 2 supply inlets/outlets.

Is there a list of the typical air change rates for each type of room? The building regs only talk of continuous extract and ventilation rates in l/s.