COMBINED HVAC AND FIRE SUPPRESSION SYSTEM

Abstract

A combined HVAC and fire suppression system includes a HVAC apparatus and a fluid outlet for release of heat exchange fluid into a discharge plenum of the HVAC system. The heat exchange fluid is a clean agent, such that release of the heat exchange fluid into the discharge plenum provides a fire suppressant effect for a conditioned space. The HVAC apparatus includes a network of piping holding a heat exchange fluid and arranged for chilling the heat exchange fluid via a chiller connected to the piping; a fan coil unit connected to the network of piping, the fan coil unit includes a coil for passage of the heat exchange fluid chilled by the chiller, a fan for movement of air over the coil in order to transfer heat from the air to the heat exchange fluid in the coil, and the discharge plenum.

Claims

1. A combined HVAC and fire suppression system, comprising: a HVAC apparatus including: a network of piping holding a heat exchange fluid and arranged for chilling the heat exchange fluid via a chiller connected to the network of piping; a fan coil unit connected to the network of piping, wherein the fan coil unit includes a coil for passage of the heat exchange fluid chilled by the chiller, a fan for movement of air over the coil in order to transfer heat from the air to the heat exchange fluid in the coil, and a discharge plenum for passage of air into a conditioned space after it has moved over the coil; and a fluid outlet for release of the heat exchange fluid into the discharge plenum; wherein the heat exchange fluid in the network of piping is a clean agent, such that release of the heat exchange fluid into the discharge plenum provides a fire suppressant effect for the conditioned space.

2. A combined HVAC and fire suppression system as claimed in claim 1, comprising a pump connected to the network of piping for pumping of the heat exchange fluid within the network of piping, wherein the pump is configured for use in a HVAC mode of operation or in a fire suppression mode of operation, wherein during the HVAC mode the pump acts to convey the heat exchange fluid between the chiller and fan coil unit and wherein during the fire suppression mode the pump is configured for pumping the heat exchange fluid out of the fluid outlet to discharged it as a fire suppression agent.

3. A combined HVAC and fire suppression system as claimed in claim 1, wherein the network of piping is connected to an expansion tank in order to ensure adequate supply of heat exchange fluid for dispersal as a fire suppression agent.

4. A combined HVAC and fire suppression system as claimed in claim 1, comprising a chiller in heat exchange relationship with the heat exchange fluid, wherein the chiller comprises a refrigeration system having a refrigeration circuit configured to remove heat from the heat exchange fluid using a heat absorbing heat exchanger of the refrigeration circuit.

5. A combined HVAC and fire suppression system as claimed in claim 1, wherein the clean agent is a halocarbon fire suppression agent such as a fluorinated ketone fire suppression agent.

6. A combined HVAC and fire suppression system as claimed in claim 1, wherein the fluid outlet for release of the heat exchange fluid into the discharge plenum comprises one or more nozzles in or near to the discharge plenum and wherein the system comprises a valve for controlling the flow of fluid out of the fluid outlet.

7. A combined HVAC and fire suppression system as claimed in claim 1, comprising an ultrasonic evaporation device for promoting the evaporation of fluid, wherein the ultrasonic evaporation device comprises an ultrasonic transducer for vibrating an evaporation surface to promote evaporation of fluid on the evaporation surface.

8. A combined HVAC and fire suppression system as claimed in claim 7, comprising a water outlet for emitting water onto the evaporation surface.

9. A combined HVAC and fire suppression system as claimed in claim 1 wherein the fan-coil unit is arranged with the fan after the coil.

10. A combined HVAC and fire suppression system as claimed in claim 1 wherein the heat exchange fluid flows through an aluminium heat absorbing heat exchanger of the chiller and/or an aluminium coil of the fan coil unit.

11. A combined HVAC and fire suppression system as claimed in claim 1, wherein the fan coil unit comprises a second coil for heating of the air, the system comprises a heater for heating a second heat exchange fluid for the second coil, and the second heat exchange fluid is provided via a second network of piping.

12. A structure comprising a combined HVAC and fire suppression system as claimed in claim 1, wherein there are multiple fan coil units and wherein the network of piping extends between multiple conditioned spaces within the structure with the of fan coil units being installed within the multiple conditioned spaces.

13. A method of providing a structure with a combined HVAC and fire suppression system, the method comprising installing and/or using a combined HVAC system and fire suppression system within the structure, wherein the combined HVAC system and fire suppression system is as claimed in claim 1.

14. A method a claimed in claim 13, comprising modifying an existing HVAC system to provide added fire suppression capabilities by: removing water used as a heat exchange fluid and replacing it with a clean agent, and adding a fluid outlet for release of the heat exchange fluid into the discharge plenum of the fan coil unit.

15. A method as claimed in claim 13, comprising using the combined HVAC and fire suppression system, wherein the method includes: operating the system in a HVAC mode or in a fire suppression mode; wherein the HVAC mode includes circulation of the heat exchange fluid within the network of piping to convey heat from the coil of the fan coil unit to the chiller; and/or wherein the fire suppression mode includes discharge of the heat exchange fluid via the fluid outlet in order to provide a fire suppression effect by distribution of evaporated heat exchange fluid into the conditioned space.

Description

DRAWING DESCRIPTION

[0026] Certain embodiments will now be described by way of example only and with reference to the accompanying drawing in which:

[0027] FIG. 1 is a diagram of a combined HVAC and fire suppression system; and

[0028] FIG. 2 shows a structure including such a system for multiple conditioned spaces therein.

DETAILED DESCRIPTION

[0029] Heating, Ventilation and Air Conditioning (HVAC) systems are used in buildings and other installations (e.g. marine vessels) to provide one or more of heating, ventilation and air conditioning. In this example a fan coil unit 10 includes a common air path are used for both heating and cooling functions, with a heating coil 12 and a cooling coil 14 placed in the air path. A fan 16 draws air over the coils 12, 14 to allow the system to increase or decrease the air temperature for controlling the temperature of a room or the like. The fan-coil unit also has a filter 24, which may be for removing particulates and/or gaseous contaminants from the air. This fan coil unit 10 can be used for air in a conditioned space (not shown in FIG. 1, but depicted in FIG. 2) such as a room of a building or of a marine vessel.

[0030] The coils 12, 14 are heat exchangers. The fan 16 causes air to pass over the coils in order to control the temperature of the air, and the treated air is discharged via the discharge plenum 34. The heating coil 12 is supplied with heated water via a heating valve 18, which is connected to pipework of a heating system as is shown in FIG. 2, e.g. using a boiler 20 to heat the water before distribution about a structure to different fan coil units 10 in different conditioned spaces 22 of a structure 26 such as a building or a marine vessel. The cooling coil 14 is for reducing the air temperature and this coil 14 is a heat exchanger with flow paths that can be supplied with chilled heat exchange fluid from network of piping 28 connected to a refrigeration system or chiller 30. The refrigeration system 30 can be a vapour compression type refrigeration system and it supplies chilled heat exchange fluid via piping 28 extending to multiple fan coil units 10 in different parts of the structure. These fan-coil units 10 are similar to known water terminal units, but in this system the heat exchange fluid for the cooling coil 14 is a clean agent such as a halocarbon clean agent in the form of Novec™ 1230 or Novec™ 7000.

[0031] In order to allow for the heat exchange fluid to be used for fire suppression a fluid outlet 32 is provided for discharge of the heat exchange fluid into the discharge plenum 34 of the fan coil unit 10. This has a valve for control of the outlet 34. There can be multiple nozzles for discharge of the heat exchange fluid, as a fire suppressing clean agent, into the discharge plenum 34. When the heat exchange fluid (clean agent) is discharged into the discharge plenum 34 it evaporates into a fire suppressing gas and it can be distributed into the conditioned space 22 by the action of the fan 16 of the fan coil unit 10. The network of piping 28 includes a pump 36 for sending fluid around a circuit from the chiller 30 to the coil(s) 14 of fan coil unit(s) 10 and the same pump 36 also acts as a pump in a fire suppression mode where it pumps the heat exchange fluid out of the fluid outlet(s) 32 of the fan coil unit(s) 10. In addition, an expansion tank 38 is provided in order to ensure an adequate supply of fluid for fire suppression use.

[0032] In this example the combined HVAC and fire suppression system also includes a water outlet 40, which can be coupled to a mains water supply such as the tap water supply. The water outlet 40 is used to allow for added fire suppression capabilities using water vapour.

[0033] There is also an evaporation system using a plate coupled to ultrasound transducers 42 for vibrating the plate and for promotion evaporation of fluid from the plate, e.g. to generate water vapour as water is provided from the water outlet 40, or to ensure that all of the clean agent is evaporator as the heat exchange fluid (clean agent) is discharged from the fluid outlet 32.

[0034] FIG. 2 is a schematic illustration of a structure 26 with multiple conditioned spaces 22, in this case two, and a corresponding fan coil unit 10 in each of the conditioned spaces 22. The fan coil units 10 can be as in FIG. 1. Each of the fan coil units 10 is connected to a network of piping 28 that includes a clean agent as the heat exchange fluid. This first network of piping 28 is a circuit with a pump 36 and expansion tank 38 as discussed above, as well as a chiller 30 for removing heat from the heat exchange fluid, which is a clean agent type fluid. Further, each of the fan coil units 10 is connected to a second network of piping 44 where a different heat exchange fluid, typically water, is circulated between a heat source 20 such as a boiler and the fan coil units 10. In this way the fan coil units 10 can provide either heating or cooling, as well as having a fire suppression function using release of the clean agent from the first network of piping 28.