Designing and constructing a great commercial building is always a challenge and some may think installing a floor cooling system just adds to the complexity.
However, in commercial buildings such as warehouses, shopping malls or airports, a floor cooling system can yield tangible benefits reducing capex and opex.
Floor cooling systems are designed to produce cooling where it is most needed, in a level close above the ground.
Floor cooling absorbs solar gains keeping the floor cool when a degree of transparency of facades is high.
Floor cooling allows for the maximum use of space and do not obstruct wall or ceilings used for natural lighting.
Before those benefits can be realized, you have to get past designing and installing the radiant system.
Key considerations for planning the floor construction of a high mass radiant floor cooling system
Floor construction types
Configuration for waterproofing of building floors against ground moisture:
Configuration for water-proofing of building floors using material in roll form at the transition between the insulated and non-insulated areas:
Joints that allow movement are generally known in the concrete construction trade as expansion joints. These provide continuous separation of the concrete slabs with a distance of approx. 20 mm and are filled with a soft jointing material (e.g. foam sheet or fibreboard), which is fixed in place before the concrete is poured. Expansion joints are not designed to break up the floor, but rather to provide separation from other objects (e.g. ducts, conduits, supports, walls). The floor cooling system does not affect the planning of the expansion joints. Connecting pipes that cross over expansion joints must be protected against the anticipated mechanical stresses in the area around the joint using protective pipe sleeves of 1m in length.
Construction joints (day joints)
Neighboring areas of the slab are connected to each other by construction joints. These are not movement joints, but rather occur simply as a result of adjoining bays being poured at different times. In order to ensure proper transmission of force form one slab to the next, these sections are combined by using tongue and groove joints or creating a positive connection with dowelled joints. P
ipes that cross a construction joint must be sheathed for a distance of 1m using protective pipe sleeves in cases where the pipe is subject to mechanical stress before pouring the concrete, for example due to the positioning of formwork over the pipe.
Dummy joints are cut into the concrete slab after it is formed and serve as predetermined breaking points. These cuts are approximately 3–4 mm wide and cut to a depth of around 25–30% of the slab thickness. The intentional crack that occurs below the cut has a certain amount of denticulation that allows transverse forces to be transferred from one concrete slab to the next. Dummy joints do not require the use of protective pipe sleeves. Dummy joints can also be of a “closed” type, created by cutting a post-casting groove approximately 25 mm deep, then using a special sealing compound and partially filling with foam rubber.
Equipment in the halls
Commercial buildings often have footings for various equipment, for example high rack storage and machine foundations, anchored into the concrete floor. The specialist engineer must remain informed about how deeply these foundations and anchor points penetrate into the concrete slab. If they penetrate far enough into the concrete slab to reach the level of the pipes, then the heating pipes must be left out of this area, creating a so-called blind area.
Radiant cooling floor systems are useful for a wide range of commercial buildings. Depending on exactly what you desire and what the purpose of the space is, the floor design and construction will differ, however, it consists of just a few separate components. This makes planning and installing an easy affair. The design philosophy for the building should be undertaken utilising the high radiant effect associated with floor cooling.
With the floor surface acting as the emitter the heat load demand can be based on the occupied zone which is usually the first 2.5m of space rather than the total height or volume of the building which is often the case for other cooling systems. This leads to a reduction in the heat loss for the building and can lead to a reduction in the plant required for the cooling load.