Downlight fittings that you commonly see in Australian homes are often an energy and comfort nightmare. They can be associated with up to five different problems. Before you go replacing a halogen bulb with an LED replacement, read this.
This outlines a possibly novel approach to improve the efficiency and effectiveness of heat pumps used for home heating, cooling and hot water. This involves placing the units in the sub-floor space to exploit the thermal mass of the ground in both summer and winter.
There’s been lots of talk of late about a hydrogen economy. I’ve looked into this. In a nutshell I can’t see Hydrogen being widely adopted for energy storage within our electricity system. Likewise, I can’t see it being widely used for transport except in some very limited cases. Its use within the gas network seems like greenwash. However there does seem to be some potential in using hydrogen as an intermediate product in creating transportable liquids like ammonia, methanol and methane for use as export feedstocks or as fuels.
by Richard Keech
Published 2018-09-23, based on investigation done in early 2017
Do solar air heaters or coolers live up to their promise?
At face value the idea of having a device which uses sunlight directly to heat air in winter seems like a good one. It’s the idea behind a number of products on the market that promise really high-efficiency heating for low cost. We can lump these together in the category ‘solar air heating’. Solar air heaters sometimes claim thermal efficiencies greatly in excess of that possible with a solar PV panel.
I thought this picture neatly shows the limitations of passive panel-based heating such as hydronic or column heaters. The thermograph shows most of the heat convecting to the ceiling, allowing much of it to be lost before it can reach the occupants of the room. This is one of the main reasons I never recommend hydronic-panel heating. In-slab hydronic doesn’t have this problem, but it does have other problems.
There’s some debate about whether the best configuration of split systems for multiple rooms is to have multiple single splits or to use multi splits.
By Richard Keech 2018-06-18
Increasingly split systems are used to heat and cool entire homes – not just single rooms. The default way that split systems are deployed is what I call single splits (and sometimes referred to as unitary split systems). These have one outdoor unit piped to one indoor unit. And repeat that configuration for each conditioned room.
The alternative, available from many vendors, is a multi-split. This configuration involves more than one ‘head’ unit for each outside unit. Often a whole home might be served with only one (larger) outdoor unit, and heads in all bedrooms and living spaces. Continue reading “Multi-head splits vs single-split systems”→