NZ houses

Macs Gold · Posted: Thu Jul 22, 2004 3:41 pm Post subject:

If you are really keen on building your own home in sturdier materials, have a look at using local stone. In the south island there is Wanaka schist or Oamaru stone (a lovely white sandstone), and there are I'm sure others around too.

karltsmith · Posted: Thu Jul 22, 2004 8:53 pm Post subject:

Effective control of humidity and temperature are the key.

My mention of double glazing was meant only as an aside (sorry if it was misinterpreted) and is what I would specifiy to increase the thermal insulation of a new build for energy efficiency. It's use with respect to condensation control serves only to eliminate the ponding of condensed water vapour you would normally encounter with single glazing.

In a single glazed house the glass acts as a condensor and it is this area that is usually the first sign of condensation as it is thinnest membrane in the house in contact with the outside air.

In a double glazed unit the argon filled air gap serves as an effective insulator so that the inside pane maintains the same temperature as the room and the exterior pane maintains that of the outside air, hence condensation on the interior pane of glass does not occur.

This is only part of the story however, the higher the temperature the more water vapour can be held or carried in the atmosphere in gas/vapour phase until dew point is reached and condensation occurs, usually seen on cold surfaces.

My point is that if you live in a closed system..in effect sealing up the house your are only exacerbating the problem as you are encouraging the humidity to rise, even through just normal respiration let alone other sources of water vapour such as the laundry etc. etc. And once the temperature drops in such an envionment condensation occurs. It costs more to heat "wet/humid" air because of the latent heat capacity of water.

If equilibrium of humidity with the outside air is achieved you wont get condensation. Of course you can spend money on a machine to do this job for you and I am sure it does the job well....it just seems to me to be very high tech way of solving what is ostensibly a simple problem.

Regards Karl....in a damp rental with a dehumidifier as mans best friend Wah

Graham Barnes · Posted: Thu Jul 22, 2004 9:58 pm Post subject:

Spot the scientist Nice One

... someone got his Physics A Level a few years ago! Clapping

10/10 for accuracy. Go to the top of the class. Clapping

Graham (a Physics teacher)