Making It real
My story in attempting to bring a new housing type that improves affordability, livability & community resilience
Even though there are a few in-ground heating options, they can either be heated by electric radiant cabling or the more commonly known hydronic hot water piped system. As they do not provide any cooling, this form of temperature control is typically an additional charge on top of the more common installed split Air systems. As the Melbourne climate is typically needing more heating than cooling energy, I was eager to not have any A/C units working long hours during the winter, so the inground heating was undoubtedly a preference. The problem I faced was that I didn't really know if I could justify the added expense for what in effect would be two heating systems. It all became evident to me when I thought more deeply about the Federal governments' desire to establish the snowy river 2.0 initiative, which was seeking to develop a hydraulic battery. This simply was a process of pumping and holding water upstream in a dam when energy was cheap and abundant, and only releasing the water to produce hydro energy when power was in high demand. This empathised to me that a battery in its purest form is simply a capsule to store energy to be released at a later point. If I could simply transfer solar energy into heating energy that is stored in the slab and then allowing it to naturally release the energy in the evening, I in effect had a house battery.
Although not as efficient as a battery where I had control in releasing its power, it helped me better manage free solar energy. Using electricity to heat the floor made it easier to decide between hydronic versus electrical coiling. As the hydronic system needed gas to be more efficient and really wanted no gas connection to the house, it was really a no brainer. The other benefit of having the electric coil, over hydronic pipes was that much less equipment was associated with the electric option meaning long term maintenance cost was less and more space within my service cupboards. After this decision, I researched the coils available and eventually selected Devanir as the preferred supplier. They were preferred mainly because of its proven track record but also in the way the people at the other end of the line were so caring and considerate in explaining to me the options that I could consider. To date, this has been the best trade experience I have ever had, yet I will reserve this opinion until the system is up and running, which leads me to my next point, the risk associated with this system.
One of the negatives of in-ground heating is that it does draw down a bit of energy to heat a slab and it takes a bit of time to warm up when initially turned on, yet if you have a suitably sized solar panel arrangement much of this could be countered by managing your power gains to supplement the times when you need to draw off the grid which will generally be early in the morning. When I mean early, I am talking about 3-4am when the demand and prices are low so that the slab is nice and toasty when everyone wakes up. However, the more significant issue is when something is found not to work after the concrete is poured, especially if your floor finish is a polished concrete slab.
The only way to repair a faulty system is to first locate the cable's fault, break open the concrete around this supposed location, and then patch up the newly formed whole with fresh concrete. As you can guess, there has never been a patch up concrete job that does not look like something went wrong. You do roll the dice when you choose the exposed concrete option with floor heating, and this time, the wrong number came up for me. I now have the dilemma of needing to break open a 300x 300 area to fix a cable without a party wanting to take responsibility for it. Not only will I end up with an inconsistent flooring finish, (a patch at my front entrance), but there is a dispute brewing as to whether the cable had been initially faulty, or the concrete damaged the line when pouring the concrete. The lesson here? Make sure the builder and the concreter are present when the cabling testing is done before the concrete is poured and give everyone a record of this test. The trick now is to try to make exercise look like a deliberate feature rather than a mistake. A great lesson to have learnt, but not really of much value to me unless I do another similar project...do I need the stress?!
I will post images of the area needing repair, before and after to show how this ended up. We are currently still working through our options.
I have jumped the gun somewhat here as the damage to the heating coil was not known for some time, but the next few blogs will simply be snapshots of work status as not too much went wrong...until we start talking about the windows.
Over 25 years experience in both the private and public sectors o f property
A lover of technology and design that is practical, beautiful and improves the way we live not as a individuals but as a thriving community.