Page 4 of 6 |
In addition to light, the sun also bathes us in radiated heat. The EarthDome mimics this method of heating from its thermal mass in the walls, floors and ceilings, which will have been quietly collecting heat radiated from the underfloor heating pipes that are themselves warmed by heat extracted from the ground source heat pumps. Strategically located insulation ensures that the heat stays where it is supposed to be and isn't allowed to escape into adjoining rooms or the outside air. This all combines to produce a very efficient heating system that emits the type of heat that we thrive in, instead of just moving hot, stale air around within a sealed space as is common with most central heating systems.
On the inside, the walls are finished in dense sand and lime renders which help to retain latent heat. The wall itself is made of aerated thin bed concrete blocks. The tiny air pockets within these blocks are very good at preventing heat from migrating through the material and these blocks are then finished off with an external layer of polystyrene insulation which is then covered in a layer of external render. The insulation profile follows a light-weight to dense material path, with the lightest, least dense materials located on the external face and the heaviest, most dense materials on the interior surfaces.
The party wall (the wall that separates the two buildings) has won an award for being the most sound-proofed party wall tested in 33 years! This wall is constructed from dense concrete blocks laid on thin-bed mortar. The reason for its superior sound-proofing is in the mortar - as a smaller proportion of less-dense material is used in a thin-bed system, there is a greater volume of high-density material than would be present in a wall using standard mortar layers. And, because less mortar is expelled due to compression by the layers of blockwork above it, the wall can be built much more rapidly than by using traditional methods. We could have progressed from the floor to the roof in one pass had we been so inclined!
Returning to the subject of efficiency, it was my intention from the outset that Earthdome should make the most efficient use possible of mains electricity. Therefore, you won't find any solar photo voltaic (PV) panels or wind generators (not yet anyway) on the site. Instead, I opted to use thermal heat pumps. These operate on the principle that there is a heat difference that can be exploited through a heat exchanger system and they run at an efficiency rating of approximately 1:4 (1KW electricity input = 4KW heat and hot water output). These systems provide hot water for the underfloor heating system and the domestic hot water supply.
Page 4 of 6 |