Table of Contents

1		Introduction
2		Is it for me?
Existing systems
3		How much does it cost?
4		What are the benefits?
5		Step by step guide
New systems
6		How much will it cost?
7		What are the benefits?
8		Step by step guide
9		Case studies
10		Where can I find out more?

New systems: Step by step guide

Design

In the design of any heating system, comfort factors such as temperature, moisture and air speed must be considered. For further information consult the Bioclimatic Building Design section.

There are also several ways to check the thermal demands of a building according to its construction, orientation, building envelope, occupancy etc, that enable you to optimise the size of the heating system.

Method to evaluate the space heating requirements of a building

"Energy audits" (or equivalent "building certifications") are being used more and more to check the thermal quality either of a new (before construction) or a refurbished building (before refurbishment starts) and are often a prerequisite for funding.

Selecting and installing the most suitable heating system

Types of Heating Systems

There are many different types of commercial heating systems. The most common ones are described below. Bear these options in mind, especially if your current heating equipment is very old, or if you are thinking of installing or changing your air conditioning system. But before choosing an alternative, determine whether the project will be cost-effective. Table 1 shows the advantages and disadvantages of each system.

Table 1: Commercial options for heating systems

• Heating with boilers: See Boilers module for more information.
• Electrical Heating with night storage: electricity flowing through an electrical resistance produces heat that is stored during off-peak hours when electricity is cheaper (night time). The stored heat will then be used during the daytime. Static storage tanks allow partial regulation and are usually used for transit zones. Dynamic storage tanks are more appropriate in higher occupancy zones.
• Heat pumps: these are reversible systems able to supply heat or cold by consuming a comparatively small amount of energy. They are recommended for new or restored buildings. Heat pumps can be found as monobloc equipment, easily carried equipment, split and multisplit equipment. The external and internal heat sources are usually water and air.
• Solar thermal energy: solar collectors can provide a fraction of the energy needed for heating. (See Solar thermal module for more information).

When choosing a combustion boiler, make sure you use the most suitable fuel, taking into account the information given in tables 2 and 3.

Table 2: General advantages and disadvantages of fuels

Table 3: Associated emissions to conventional fossil fuels

Heat Distribution systems

There are basically three heat distribution alternatives:

• Water radiators: this is the simplest and cheapest system. Cast iron radiators have higher thermal inertia and are more resistant than brazed steel or aluminium radiators. Bitubular distribution is preferable to monotubular because it gives better heat distribution. Surface temperature is 60-80°C.
• Radiant floor: several chemically crosslinked polyethylene pipes are set 3-5 cm below the floor surface and are separated 10 to 30 cm from each other. Water circulating at 45°C ensures a floor temperature of 29°C.
• Fan-coils: these systems include a radiator through which hot water circulates. A fan pushes air through the radiator and distributes the heat around the room. As the fan can be turned on and off quickly they are good for sudden changes of heat load, for example, in theatres or concert halls. They can also be used for air conditioning if warm water is replaced with cold water.

Control of heating systems

By installing a good control system, the amount of heat used can be controlled to meet the demand at different times and in each building zone. The most suitable regulation and regulation devices are:

• Programmable clock: This is installed in the boiler and is used to control switching on times and remote thermostats.
• Chronothermostat: a programmable thermostat. This varies the temperature set each hour, day or week.
• Thermostatic values: These are installed on each radiator. They enable individual adjustment according to local conditions or preferences.
• Zone regulation switchboard. Temperatures for different zones can be programmed independently. This requires several independent radiator circuits (each controlled by motorised valves operated from the switchboard), as well as inner temperature probes.

Independent meters for shared central heating and district heating systems

Centralised systems are more efficient than individual ones, and both the investment and operating costs are lower. However, these systems have the problem of allocating individual heating expenses to each user. If all users simply pay a flat rate charge there is no incentive to control usage and avoid waste.

Heating systems sometimes supply heat to buildings with high occupancy and differing demands during the day due to different orientations, occupancy rates etc. In these cases, the recommendation is to use stand-alone thermoregulation and individual heat meters.

Pipe insulation

Any heating system should have well insulated distribution pipes, valves, tanks, boilers etc to reduce energy losses and ensure that all the heat paid for is delivered to the places where it is needed.