An Eccentric Anomaly: Page 8

Ed Davies's Blog


I can now drive on to my land. Starting Wednesday last week the contractors (JW Sinclair) put in the entrance, track, and parking and turning space and cleared the topsoil down to clay for the house site.


Gorse and Willows

I'm busy waiting for the structural engineer to come back with design details and the roads department to issue a road opening permit so I can get the contractors in to make the entrance, access track and parking area to the north of the house.

In the mean time I've been mucking with vegetation a bit. Not the greatest use of my time but it at least gives the feeling of getting stuff done which is better than getting frustrated at the rate the year's slipping by.


A Rant About Kilograms On Mars

The CACM have published a reasonably interesting article by Gerard J. Holzmann about verification of the software on the Curiosity Rover: Mars Code.

Near the beginning, though, it says:

On Earth, Curiosity weighed 900 kg. It weighs no more than 337.5 kg on Mars because Mars is smaller than Earth.



Vapour Resistance of OSB

In the past there's been a lot of confusion in discussions on the Green Building Forum (GBF) about the ability of OSB to impede or allow the transfer of water vapour. This is quite significant as OSB is a handy and cheap material for wall and roof constructions where movement of water vapour is a significant concern (although by which modes and in which directions is also a bit controversial).

Somebody using the pseudonym “A.L.” on the Navitron Forum sent me some references and discussion regarding my concerns about my roof build up following on from discussion on the GBF: Ventilation gap under sarking board which might throw some light on the inconsistency of quoted OSB vapour performance values.


Interior Design

After a couple of rather numeric posts it's time for something a little more entertaining. I've previously shown some images of the planned exterior of the house but not said much about the interior design so …


Heatloss Calculation

My house designer is, understandably, a bit concerned about how he'll put the rather unconventional heating arrangements for my house into the SAP software. The other day we were discussing the emitters (radiators) involved and talked briefly about the size that would be required if we were to ignore the heat leakage from the thermal store which should in practice supply a lot of the background heat needed.

To get a grip on this myself I decided to update my heat loss calculations to the slightly evolved design of the house and to allow for the regulatory requirement that the emitters should be sufficient to keep one apartment at 21 °C and the rest of the dwelling at 18 °C.


Planning Permission

I seem to have planning permission.

Looked online earlier today and it wasn't there but looked just now and it's shown as having been granted yesterday.


MHRV Heat Exchanger Area

In my recent MHRV Ventilation Requirements post I established that I need the heat exchanger in the ventilation to recover about 1200 watts of sensible and latent heat from the outgoing airflow to warm the cruel cold air coming in from the outside.

Next it's worth working out the area of interface needed between the outgoing and incoming airflows to achieve this. This might seem strange without having first decided on the design of and materials in the exchanger but actually, as I'll show, the actual materials used don't make a lot of difference.


MHRV Ventilation Requirements

Having got the design of my heat exchanger significantly wrong I'll, for now, just post the requirements bit which I'm fairly happy with.


MHRV Oppsie

Over the last few days I've been writing a fairly detailed blog post about the design of the mechanical heat-recovery ventilation (MHRV) for my house. I got it all finished yesterday afternoon, did some shopping, then settled down to proof read it before uploading in the evening.

As I read it I thought of a point I should, perhaps, describe a bit more carefully so started scribbling a little diagram to help explain it. At this point I realised that my whole design (of the MHRV heat exchanger, not just the description in the blog post) was badly wrong.

Oops - feel a bit like this kitten. Back to the beginning - a post on the basics…