@solarventi, Hi, sorry, I didnt work it correctly, It is an interesting concept, but I am not getting it>>> bit slow... How do you heat up in winter in Vic when we get very little sun and the weather has turned Artic this year, Main reason I am noticing the cold, especially when working outside. I do have low blood pressure so feel the cold, but the red clothing next to skin works a charm. I would like to understand... I have seen on uTube where they DIY passive heat I liked the pictures but no explanation and these were using exisiting windows .. I this with gap at bottom on outside so cold air comes in and gap at top on inside so warm air into house.... but got to technical for me. And I get confused, as hot air rises and I dont understand why fans are at the top in newer models not at bottom [of heaters] But I would mind understanding how it works.. Am going to check the website, TU very much. I have bats to put in kitchen reno but would like something to attach to the corrogated iron so there is no gap between iron and bats. Appreciate your help and will check again on your site to see if I missed anything :)

we're building in Childers Qld (Zone 2) on top of a hill 120m above sea level with no chance of being built-in as we are on a 69 acre block. Quite windy all the time predominately from the SE. All outside doors will be security. Roof has vents in the gables on all four sides so I can leave open to purge heat during summer and close off in winter. Bed 2&3 doors used to be adjacent bathroom door for cross breezes but a layout change in the bathroom meant having its door on the east now. Not ideal but necessary. Dark colour unfortunately is dictated by our very red soil that will stain any light colour so had to go dark, would of preferred light. So I should make my eaves 1200mm all around?

we have several Solar Skylights ...one square 45cms Illume fitting in an ensuite without any windows and two 30cm Arcol circular fittings to add extra light to a dining area without direct external windows...we're very happy with the Solar Skylights after years of leaking "proper" skylights ..our roof windows and standard skylights looked excellent with a view of sky and trees but, tired of constant leaks, we changed the roof and swopped the leaking holes for the small Solar Skylights .....they averaged about $260 each and can be DIY although our tradesmen were happy to install while doing other work for the cost of about 1 hrs extra labour...some brands have a model that includes electric connection to use the same light for night and overcast days but we have extra downlights instead .. they're just solar powered light fittings, ceiling mounted with a fibre optic cable through ceiling and roof space, up to 9 m (so plenty of options to disguise the cable instead of more complicated access to roof through a second storey) and then out under the ridge capping to connect to a small roof mounted solar panel...only problem is i kept trying to turn off the "light" until we became used to them ...there are also custom sizes and they can also be installed vertically to have the appearance of a window or fanlight over a door...very satisfied

You have to be careful because there's several different meanings to the term 'variable speed pump'. True "variable speed pumps" are generally used in hydraulic systems of commercial buildings, where you have variable flow requirements due to valves opening and closing on the system. In that case, a variable speed pump can slow down or speed up to suit the required flow rate, which is more efficient than a single speed pump which just runs at the maximum speed all the time, wasting energy if only a small flow is required. However, many pumps come as a multi-speed option which means they have a switch that allows you to adjust the speed. For a pool filter circuit, you're right in that the pump is either running or it isn't - there's no variable flow rate required. However, you want to make sure you don't oversize the pump otherwise it uses more energy than required. Equally though, you don't want it undersized. Is your pool heated? If so, the energy required to heat the pool will MASSIVELY exceed the energy to run the pump!