Febco825YAparts diagram

If you’re building a new home, chances are you’re pouring a new concrete floor slab. But if you’re remodeling an existing property, you might already have a floor slab.

Febco825YArebuild Kit

The smallest area you can reasonably install hydronic underfloor heating is around 40m2. Significantly smaller than this, and it’s probably going to be cheaper to just use an electric system.

So you’re building your new dream home, and you love the idea of comfortable, radiant heat keeping you warm all winter? Here are 3 things you’ll need to consider before you start building.

If you’re planning to install a solar energy system, the electricity you generate will help power the heat pump. So in that case it can be a cost-effective option as your running costs will be almost nothing.

FEBCO 825Y spec Sheet

febco825ya3/4

In this case, we recommend the topping slab to be 90mm thick. There should be two layers of steel mesh – the bottom layer on 20mm chairs, with the hydronic pipework tied on top. Then a second layer of steel should be placed over the pipes which helps stop the concrete surface from cracking. The pipes are generally 16mm diameter, so this arrangement gives you 50mm concrete cover over your pipework.

lf825ya-fs - 1"

You’ll also need to consider which type of heat source you intend to use. In Australia, hydronic radiant floor heating systems are often heated by gas boilers which have the lowest installation cost. However, the price of gas is increasing so running costs are not as low as they once were.

Alternatively, you might pour an additional topping slab over your structural slab. This is common if there is an existing structural slab, or if your floor will have a polished concrete finish – the topping slab has different properties to the structural slab which makes it better for polishing.

As a final option you might look into a low-profile system such as Uponor Minitec which can be installed on top of an existing slab and is only 15mm-20mm thick. This type of system is more expensive however.

As a rule of thumb, if you’re only heating bathrooms then electric underfloor heating is probably better. The reason is that it’s a small area (usually only 2-3m2) and it’s not in use for long periods of time.

Series FE825YA Small Footprint "N-Shape" Design Reduced Pressure Zone Assemblies are used to protect against high-hazard (toxic) fluids in water services to industrial plants, hospitals, morgues, mortuaries, and chemical plants. They are also used in irrigation systems, boiler feed, water lines, and other installations requiring maximum protection. They feature a bronze body and threaded ball valve shutoffs. Maximum Working Pressure: 175 psi (12.1 bar).

febco825ya2"

As an alternative, electric heat pumps are becoming more popular, especially for properties without a connection to the gas network. These are more expensive to install than a gas boiler, (normally $5k – $10k more expensive) but are economical to run.

Wilkins825YA

However in Australia, many people prefer not to have heating in their bedrooms and opt to have underfloor heating in just their living room, or only in wet areas like bathrooms.

In short, electric systems are cheaper to install but more expensive to run. Hydronic systems are more expensive to install but cheaper to run.

In a new slab, the easiest and most cost-effective method to install the pipework is to tie it to the steel reinforcing mesh. Once the mesh has been laid, we can install the pipework, ready for the concrete to be poured. In this case the hydronic pipework is installed within the structural slab.

Ultimately you’ll have to make a decision based on your budget, how long you intend to live in the property, whether you have gas or 3-phase power available, and your preference for renewable vs non-renewable energy options.

However, if you’re heating an open-plan living/dining room, often a hydronic system will be more cost-effective over time.