Underfloor heating, Radiators, Ducted central heating

Heat source options

Natural Gas Boilers, LPG Boilers, Pellet Boilers, Diesel Boilers, Heat Pumps and Wood Boilers

Radiators

Radiators are fast acting and the most flexible system available for home central heating. Each radiator has its own temperature control so each room in your house has individual temperature control. In most situations a radiator central heating system is cheaper to install and cheaper to run than an underfloor heating system while almost matching an Underfloor heating system in terms of comfort. Radiators are our preferred choice of central heating for kiwi homes.

Features

A radiator system is a safe, stylish and healthy way to heat a home as there is no forced air draughts and they are not too hot to touch.

P.L Gas and Solar Ltd predominantly use DeLonghi radiators supplied by Central Heating New Zealand Ltd. They are perfectly safe for children, the elderly and pets. Their surface warms to between 60°C and 85°C. They will not affect curtains or furniture placed in close proximity. They are also very effective at drying clothes on days when outdoors drying is not possible!

The model of radiator installed in any room is determined by the specific heating requirements of the area (kW output), and the position of the radiator in the room. For example, there are long and low models for wide wall spaces, and taller models for narrow wall spaces.

Designer Radiators

DeLonghi also produces a number of designer radiator models in modern and funky shapes and sizes. Many people highlight these as décor features in their home because of their unique visual appeal, although their output is usually somewhat lower than models in the standard range. While many of the designer radiators are creative designs, a popular choice is the Multi Colonna radiator (right). It fits in well in renovated homes due to it's traditional style.

The designer range is available by indent order only.

Towel Rail Radiators

DeLonghi towel rails are an ideal complement to any central heating system. They are really useful in laundry areas as well as bathrooms. These also come in a standard and designer range, and can be painted to any colour you choose.

Design Considerations

• Pipe work runs from the boiler to radiators situated throughout the house. In a wood framed home, pipes run through the framing timber like the electrical and plumbing services. In a house constructed of concrete, pipes can be run between wall and ceiling batons or chased into the wall. As with any service, careful consideration needs to be given to how the pipe work will run within the house structure.
• Radiators are most effective when positioned in the coldest part of a room, where there is likely to be the greatest heat loss. Optimum position is immediately below a window. The next best location is elsewhere on an external wall. If neither of these can be achieved, position radiators as close as possible to these points.
• It is not ideal to position radiators behind full length drapes, as heat will be trapped behind them and not directed into the room.
• Avoid placing radiators next to a bed head, or behind a solid object that will inhibit the natural spread of heat.
• Radiator effectiveness can be maximized by situating them under a protruding ledge, windowsill or mantle, which will help the heat to flow into the room.
• To ensure an even temperature is achieved throughout the home, radiators should ideally be placed in every room, including hallways, toilets, bathrooms, bedrooms and living areas.
• In multi-storey homes, radiators should also be placed in upstairs rooms and on landings. Based on the UK standard, allowance is made for 25 percent of heat rising to the next level in a well insulated home. A reduced output requirement is therefore factored into calculations for upper levels.
• In some larger rooms it is preferable to split the total energy output over two radiators, to ensure an even temperature throughout the room with no cool or hot spots.
• Often a system will be capable of achieving a higher then recommended energy output, even at extremely low outside temperatures. All radiators are thermostatically controlled, and can be turned off altogether. All systems include time and temperature controls, allowing home owners to tune a system to their individual preferences and requirements.

Heat sources that are suitable for Radiator heating are: Natural Gas Boilers, LPG Boilers, Pellet Boilers, Diesel Boilers and Wood Boilers

Ducted Central Heating

Gas Ducted Central Heating is still the mainstay of P.L Gas and Solar Ltd's supplied systems. These systems are relatively fast to install and the most cost effective systems to install in single level homes. Gas Ducted Central Heating has the fastest heat up time compared with the other heating systems and running costs are usually on a par with radiator central heating systems.

Ducted central heating comprises a central heating unit, which is connected to a series of outlets. Positioned strategically throughout your home, these outlets, or ducts, are installed either in the floor or ceiling. Installation of the heating unit depends on your house. If your house is built on a concrete slab, the unit is installed in the roof. If it has space underneath or a very low roof line, the unit is installed outside or under the floor. The ductwork, which connects the outlets to the heating unit, is neatly tucked away out of sight.

At P.L Gas and Solar Ltd we use Brivis gas central heating furnaces. These furnaces come in either internal or external units in standard mid or high efficiency models.

Under Floor Heating

Underfloor heating is the most comfortable way to heat a home!

• Because the heat source is at the feet, the perceived comfort level is greater. As a result, actual room temperatures can possibly be one or two degrees below those required with other systems – resulting in energy cost savings. However, if the system is used for only short periods of time and at infrequent intervals, radiator systems may return a lower running cost.

NB: Care must be taken with the choice of floor coverings. In general, underfloor heating works best with tiled or concrete floor surfaces, although it still works very well with wooden and carpeted floors. Home owners should advise which floor coverings they intend to use at the time the heating system is being designed.

Installation and design

P.L Gas and Solar Ltd use uses pipes designed in Europe specifically for warm water systems supplied to us by Central Heating New Zealand Ltd . They are strong and durable, enabling them to be laid in a concrete slab without risk of damage. The piping is laid in loops and secured to the reinforcing mesh in the slab during construction (or an insulation layer within the slab – see below). Each loop runs back to a central point and connects to a central manifold, enabling different heating “zones” to be established within the house. Each zone can be controlled individually using a thermostat and timer.

When the heating system is designed, the distance between pipe loops is calculated according to the area of each zone – ensuring optimum heat levels are achieved. The client’s personal comfort preferences are also taken into account.

The European Method

In New Zealand, underfloor heating (both electric and water) has traditionally been laid within a 100mm thick concrete floor slab, as this is how most houses are constructed. This is referred to as the ‘hangi’ method. However, in the rest of the world a rough floor slab is laid first, followed by a layer of polystyrene (or latterly polyurethane) insulation. The pipes or cables are then attached to the insulation, and a 30mm screed is poured on top. This means the heated floor is much thinner and has a far quicker reaction time up and down. It is also completely insulated around the perimeter of the slab. Energy costs and wastage from heat loss into the ground and through the perimeter are reduced considerably.

This method is catching on in New Zealand, although the construction design of the house has to be considered. Energy savings of up to 30 percent are achievable over standard in-floor designs.

Design Considerations

• Primary pipe work runs from the boiler to the underfloor manifold. It can be run in a lagged and sheathed conduit in the tailings under the floor slab, or in the framing timber. Primary pipes are usually 25 – 35mm in diameter. Once lagged and sheathed, they are typically 65mm in diameter.
• The underfloor manifold is generally best positioned in the center of the house, as all underfloor pipes emanate from it. Very large houses may require two manifolds. A small (typically 750mm x 1000mm x 150mm), flat cabinet is installed to house the manifold and underfloor pump. This can be recessed into a wall in the same manner as an electrical circuit board. Typical locations would be the back of a hall cupboard, laundry or equipment room.
• All houses with underfloor heating should employ the best possible insulation under the slab, to limit downwards heat loss. We recommend at least 50mm of high density polystyrene be laid under the slab. We also recommend 25mm of edge insulation, as up to 15% of the heat can be lost through the edge of the slab. This can be polystyrene or treated wood, laid on its edge.
• The underfloor pipes are laid and attached to the reinforcing mesh, which is supported by chairs. The recommended distance of pipes below the surface of the concrete slab is 30 – 40mm. This is to ensure an acceptable response time.
• Because of the proximity of the pipes to the surface, we recommend no saw cuts in the slab. There are several crack-inducing products on the market that eliminate the need for cutting.
• As a rule of thumb, the maximum length of any loop is 100 meters. Loops are continuous (ie, no joins at all). The maximum number of loops per manifold is 12.
• Three variables are used in the design, to determine output:
  1. Water temperature. 2. Water flow. 3. Pipe spacing.
• Depending on the design, the temperature of water used for underfloor heating is typically 40°C to 60°C. The maximum temperature the floor slab should reach is 29°C. On average it is around 26°C. The air temperature produced in the room is approximately 5°C lower than the floor temperature.
• The output requirements and overall design of the system determine the number of loops emanating from the manifold.
• A pressure test on the pipes is undertaken after the slab has been laid. If a pipe within the slab is damaged during construction, it is possible to chip away the concrete and repair it.
• Heat sources that are suitable for underfloor heating are: Natural Gas, Pellet Boiler, Diesel Boiler, Wood Boiler and Heat pump