Boiling is a normal part of vacuum tube systems.
Time of year for boiling will differ with regions of Australia as well as time of year.
In 2017 Mt.Isa had similar times for boiling as Tasmania, however Tassie boiled in winter where Mt. Isa didn’t.
It is not necessarily the hottest days, it’s more to do with the Infra-Red levels. At our Research facilities in Diamond Creek, Victoria, we found that boiling did not occur on 40 degree days but did occur on 30 degree in Summer as the IR was stronger.
Boiling does NOT damage the system.
It varies from;
- Steam from breather pipe
- Splutter from header tank exhaust hole
- Occasional rattle while boiling
Water loss is minimal in the vicinity of perhaps a cup – 250ml.
(boiling doesn’t occur if you are using sufficient hot water)
Although most times it is not noticed, if you do have excessive boiling in Summer, there are a few solutions we have used;
1. Use more hot water
2. Partly over the tubes with a shade cloth.
Make a channel, or run a string on a pulley or draw roller on each side of the frame
Pull up and down according to time of year or high IR
2. Partly wrap the tubes with silver foil insulation
I have a preference for covering all the tubes and varying height of tubes that get covered. This way you get consistent usage over all the tubes.
In practice will this make a difference over covering 4 or 5 tubes, I don’t know, but it will work just as effectively.