When selecting heating systems for a garden centre it is essential to consider the different nature of the various spaces involved. As garden centres vary considerably in their layout, structure and facilities provided for customers this means that there is no off-the-shelf solution.
There are essentially two types of heating technology that can be used to provide efficient solutions for the types of spaces found in garden centres. These are warm air heating and radiant heating.
As its name suggests, a warm air heater warms the air in the space to provide comfortable conditions for customers and the work force. Heaters may be suspended from the roof, mounted on the wall or free standing on the floor. In the latter case this will occupy some floor space that is then not available for other purposes however access for maintenance is likely to be easier.
A well-designed warm air heating system will distribute warm air throughout so that there is little temperature variation across the heated space. It is important that equipment of an adequate heating capacity is selected together with positioning of warm air heaters to ensure that the warmed air is able to travel freely and therefore distributed evenly throughout the space taking in to account any obstacles thus avoiding ‘cold spots’.
Warm air heaters pass air across a heat exchanger to increase its temperature and then distribute it through the space using a fan. The fuel source can be a gas or oil fired burner built into the heater (indirect fired), hot water supplied by pipework to the heater from a centrally located heating plant such as a boiler, or an electric element. Modern indirect-fired warm air heaters are now available in high efficiency condensing versions.
Radiant heating is typically gas fired and is provided either by suspended radiant tubes or, less commonly, by radiant plaque heaters which may be suspended or wall-mounted.
Both types of radiant heaters emit infrared radiation from hot surfaces and it is the infra red emission that warms people and other objects. Whilst radiant heating does not warm the air that it passes through, the process of convection from the warmed surfaces will increase the air temperature as a secondary function.
Radiant emissions only warm objects, such as people, that are in ‘direct line of sight’ of the heating source, this needs to be borne in mind when positioning radiant heaters.
The characteristics of the different types of heating described above will determine the type of heating that is best for each type of space within a garden centre.
Warm air heating is usually the best solution for enclosed spaces within a garden centre; such as indoor retail areas, cafeterias etc. Usually the heaters will be mounted at high-wall or roof level to free up retail space, while also ensuring that the merchandise displays do not obstruct the even distribution of the heated air. Click here to see a recent installation of a warm air garden centre installation.
If the space is likely to be reconfigured on a regular basis, floor standing heaters with directional warm air outlets might provide greater flexibility to accommodate future changes in layout.
In areas such as cafes where people may be seated for a while it is also important to avoid draughts.
Those areas that are partially open to outside air, and therefore undergo constant air changes, may benefit from radiant heating as it does not directly warm the air but will warm customers as they browse.
Due to the temperatures attained by radiant heater emitters they will need to be positioned a reasonable distance from people and stock. Particular care must be considered when siting in the vicinity of tall plants to avoid damaging them. Care must also be taken to ensure that plants and stacked stock do not ‘shade out’ other areas from the radiated heat. Where plants are part of a permanent display it is necessary to be mindful of future growth.
If any area of the garden centre has a high roof then warm air will naturally rise producing a temperature gradient between floor and roof. This results in a waste of energy but can be minimised by the use of destratification fans mounted just below the roof to circulate the warm air back to low level, thus saving energy and improving the comfort of both customers and staff.
There is more detailed information about this in our blog on destratification
In all areas it is important that the heating is controlled effectively to ensure that comfortable conditions are combined with efficient use of energy. The control strategy will need to be aligned to both the layout of the space and the ways in which different areas are used. For example, zoning the heating system will enable different areas to be controlled in different ways.
There will also be benefits to using timed control to switch the heating on before the centre opens to ensure the building is warm when people arrive and also turn it off at the end of the day. The morning pre-heat period can be combined with temperature optimised control to vary the pre-heating period, the heating plant switched on time will be delayed on days when the ambient air temperature is warmer, the result of which will be seen in saving energy and a reduction in the cost of energy bills.
A more detailed discussion of heating controls is provided in our Guide to Controlling Your Heating System.
As noted at the beginning of this document, the key consideration is to understand the nature of the spaces to be heated and designing a system that accommodates their varied requirements.
It will also pay to work with specialists in this field who not only have the experience and knowledge to deliver the most appropriate solution but will also provide all of the support needed to ensure a successful project. Powrmatic offers a ‘without obligation’ site survey, heating load assessment and system design service – along with ongoing technical support through to commissioning and beyond. Click here to see the various options for your garden centre heating solutions.