NEW HOMES
HYDRONIC DESIGN GUIDANCE
New Homes Hydronic Design guidance
Three critical design factors for your home in temperate climates:
- Orientate – Face towards the Sun; Southern Hemisphere North facing glass or South Facing glass for Northern Hemisphere. You want to minimize east and west windows.
- Insulate – Insulate as much as possible or practicable. Ideally insulation on the outside of the building envelope; you are trying to insulate the thermal mass.
Aim to make it airtight as possible. Passive Haus principle is no more than 0.45 air changes in an hour.
I would also suggest considering a Heat Recovery Ventilation (HRV) or Energy Recovery Ventilation (ERV). You need fresh air into an air tight home, which this equipment does as well as filtering air containments (great for removing smoke) with very economical running costs. - Thermal mass – Thermal mass on the inside of the insulation; concrete slab tremendous thermal mass, also internal brick or concrete walls.
You get this right and heating and cooling any home is remarkably simple and straight forward.
Insulated Concrete Slabs
This is the most critical aspect of inslab heating.
An uninsulated slab will increase your running costs significantly, 50% or more in additional costs is not uncommon. With the heat transfer from conduction, heat is moving in the solid object (concrete) in all directions equally. The amount of heat transferred from your heated 40 degrees water pipe to the concrete is enormous; the loss or wasted energy from the concrete into the ground needs to be stopped, you need a thermal break between the ground and the slab.
Insulation under concrete slabs has been standard for decades in colder climates around the world.
Insulation is required in climate zones 8, but only edge slab insulation for climate zone 7 with inslab heating under the BCA.
See below some design schematics to assist your builder or engineer with a good insulated slab design.
Also we have some pictures for an insulated concrete design in the gallery page.
