Colt-Caloris - Frequently Asked Questions
1. What are the primary benefits of the system?
Water as cooling medium
- Refrigerant charge is minimal and local to the unit. So no piping leaks, but if there was a leak, only a small amount would discharge from the unit - not the whole system as with other forms of AC.
- The system allows unlimited number of units and piping lengths.
- Un-insulated pipe-work (plastic recommended) therefore significant time and cost savings for installation contractor and no need for specialist piping skills.
- Flexibility of system: easy to install and alter (e.g. add or omit) - it is only low pressure neutral water!
Costs
- System capital costs low;
- System efficiency and running costs, unit COP up to 7.
Efficiency
- Energy reclaim between all units connected to the water system.
- Neutral temperature (20-25°C) of two-pipe water system. Being close to the building temperature it uses the thermal mass of the building, which leads to even greater system efficiencies.
Low noise
- Noise levels of units, typically NR28 to NR35
Additional Benefits
- Control: Total individual control for heating and cooling at all times according to end-user selection.
- Dimensions: Slim depth of horizontal units, only 247mm deep
- Quality and reliability: Other units are unaffected if one room develops a problem or is relocated.
- Ease of installation: Reduction in pipe-work co-ordination and space.
2. How is the Caloris WRF system going to be affected by the inevitable F- Gas Regulations, coming into effect on 27 July 2007?
Colt is aware of the regulations for the registration and competency of installers, and annual on-site post installation joint testing of systems with more than 3 kg of HFC refrigerant.
Since the Colt-Caloris internal heat pump units each contains less than 3kg of refrigerant, they are unaffected. Only the outdoor unit will require annual inspection during normal regular routine maintenance.
3. Does the refrigerant charge cause the need for additional leak detection in rooms?
No, unlike large VRF systems, which have typically 10 to 50 kg of refrigerant in a system, the refrigerant levels in all Colt-Caloris units has been kept to an absolute minimum. The quantities are very small when compared to any VRF system and this enables Colt Colt-Caloris to satisfy the constraints of EN 378 safety laws with ease. The actual refrigerant contents are as follows:
Size 1 0.39 kg
Size 2 0.75 kg
Size 3 1.10 kg
Size 4 1.35 kg
Size 7 2.65 kg
4. What does the Colt-Caloris system cost to install?
The system cost is clearly a function of the size and complexity of the units and the project, although as a guide only, we would suggest £100 to £120/m² full system cost at 2005 prices, including the provision of primary fresh air supply and exhaust air. For clarity this would include:
- Colt - Caloris room units
- Primary heat pump(s)
- Water system
- Valves, headers, flow setters and connections
- Ductwork and grilles
- Installation of all items
- Commissioning
- Primary fresh air: Air-handling (AHU), supply and return, and associated ductwork.
5. Where has the system been installed in the UK?
Daimler Chrysler (Milton Keynes)
Alexandra Hospital (Harlow)
The Alfred Denny Building at the University of Sheffield
Assura Medical Centre (Macclesfield)
Luton Hoo Hotel (Luton)
EON UK (Lockerbie)
Colt Holland and Germany have completed over 60 installations, which are also being monitored closely and are achieving full client satisfaction.
6. Can Colt offer a full turnkey installation for the system?
Yes, Colt will be happy to consider these works.
7. What are the maintenance considerations?
The Colt-Caloris unit has been designed as a reliable sealed for life unit manufactured under strict Quality Standards. Maintenance is simply regular cleaning of the filters and condensate drain tray, as per any typical Fan Coil installation. The theory being, that should a unit component breakdown, it is more cost effective to replace the unit than carry out on site repairs.
8. What are the running costs associated with the Colt-Caloris system?
The Colt-Caloris system is currently undergoing fully independent investigation and testing to determine the system running costs. These demonstrate annual running costs below that of VRF and certainly four pipe fan coils.
From initial monitoring and calculations we state the running costs in part-load conditions (outdoor temp approx. zero to 20°C) are much better than VRF since the net COP of the Colt - Caloris units is better at part-load conditions. Further, in part-load the central heat-pump is hardly (or not) running at all. Records of 2005 suggests a cost of some £5 per m² pa.
Whilst in full-load operation (cold frost and heat wave) the Colt-Caloris system will perform similar to VRF, though still better than fan coil designs, including chillers and boilers.
Unlike VRF, additional thermal buffer will further reduce energy costs.
9. What equipment warranty is provided?
The standard equipment warranty offered by Colt for all its equipment is 2 years. However, we are happy to discuss this warranty with respect to your client's specific requirements.
10. What are the typical noise levels and how have these been tested?
Output results in noise levels of between NR 18 -36 in average "installed, live" conditions
Colt has its own acoustic test facility.
The units have also undergone independent tests carried out by the Laboratory of Acoustics Peutz & Associates BV at Mook, Holland, in accordance with:
ISO 354:1985 and ISO 3741:1999
ISO 3741:1999
ISO 5135:1999
BS4856:1997
EUROVENT 8/2-1992
Further tests at UK based Sound Research Laboratories have been undertaken.
11. Has Colt carried out whole life costing for the Colt-Caloris system?
Whole life costing will be project specific, but based on the competitive install costs, low energy consumption and the lack of maintenance due to the sealed for life concept we find whole life costing shows the Caloris system to be very attractive. We are happy to assist in this analysis further with the specifier.
12. Has the indoor unit a vibration risk?
The Colt-Caloris units have a total of 14 internal anti vibration mounts, several types, all specifically designed and tested for this application. The most significant possible cause for vibration would result from the compressor, and would need to pass through three stages of internal anti vibration systems which isolate the compressor from the unit casing.
13. What is the Heating / Cooling output range of the outdoor Colt primary heat-pump?
The cooling capacities of the units range from 11kW to 310kW in UK conditions.
The heating capacities range from 14kW to 245kW in UK conditions.
Of course multiple heat pumps can be combined extending the system capacity infinitely.
14. Does the outdoor heat pump unit require a defrost cycle during long cold spells and does this lead to unavailability of heating during the cycle as with VRF systems?
Yes and No! During long cold spells, Yes, the outdoor heat pump unit will ice up; this is normal for any heat pump unit including all VRF systems. HOWEVER unlike VRF systems which have to STOP heating the building during the de-ice period and reverse cycle (so that the indoor unit coils are then cold evaporators and the outdoor coil is warm), the Caloris system can use its water system as a buffer and carry on heating occupied spaces!
Therefore no - it does not lead to heating unavailability.
Please note, while de-icing, which takes approx. 15 minutes, all VRF systems will stop providing heating to the end users, often resulting in users complaining about cold drafts from the indoor evaporators and refrigerant/control valve noises. Worse still, energy is consumed by the refrigerant compressor in the de-frost cycle.
The difference in comfort control during de-icing is a major advantage over VRF installations.
15. What are the electrical input requirements for the indoor units?
The units are supplied with a 230 / 1 / 50 supply and internally fused. The full electrical details are included within the product literature. Up to four size 1 units can be connected to a 13 Amp supply.
16. Can alterations to the system be easily made?
Yes of course, since the connections are only un-insulated water flow & return pipes, and low power electrics.
Should this be a likely requirement, we recommend local and branch / mains isolation valves be incorporated into the pipe-work network and these can be used without detriment or damage to the system or other units operating on the system.
17. What level of quality control do the units undergo prior to despatch?
Colt have an active manufacturing policy of zero defects. This means that every unit is tested as follows:
- A pre-leak test with pure helium sniffer equipment (helium has much smaller molecules than nitrogen used by many manufacturers and for site fabrication of large VRF systems.
- A double pressure test at 38 bar dry nitrogen.
- Check that the unit vacuum is held at least for 8 hours at less than 1 micron.
- A leak test at 0.8 grams annually with refrigerant leak testing equipment.
- The units undergo a full running test for a minimum of 72 min, under surveillance in both the heating and cooling modes.
- Each unit undergoes a full electric and PCB software self test wiring procedure.
- Colt also observes the full quality control measures as specified in ISO 9001 and QC procedures.
18. What refrigerants are used within the system?
The only refrigerant within the system is a relatively small charge within the indoor units, which use Chlorine free refrigerant types with zero Ozone Depletion Potential (zero ODP).
The system can use indoor units with R 134a, R407c and/or R410a.
Different modern refrigerant types have been used to maximise unit efficiency versus application from a common design for all units.
19. Are vertical Colt-Caloris units available?
Yes, 3 sizes are available from 1 kW to 3 kW.
20. Would we recommend using Caloris in a mixed mode system, and what are the benefits?
If the client is going for a mixed mode system with air conditioning, then Colt-Caloris has the same benefit as normal, e.g. it is energy efficient.
If the client requires mixed mode then their motive is usually comfort & energy efficiency so Caloris is ideal.
21. Can we compare the Colt-Caloris system and Water cooled VRF systems?
Yes- see as follows:
|
|
Water Cooled VRF
|
Caloris
|
| Piping type |
refrigerant |
water |
| Insulation |
required |
not required |
| COP/EER |
good (1) |
good (better in part load) |
| Branch boxes |
required(big) |
not required |
| Refrig install qualified |
required |
plumber |
| Reliability if something fails |
whole system |
just one unit |
| Piping length |
limited |
unlimited |
| Piping height |
limited |
unlimited |
| De-icing of outdoor unit |
no heat inside |
indoor units keep on working |
|
|
|
|
NOTE (1): However the CoP/EER drops considerably in actual use as the compressor has to pump high pressure/velocity refrigerant around the system and the standard separation is only 5 (five) m in total. On average the COP will reduce by some 10% and EER by 15%.
22. What is the percentage improvement in performance and efficiency of laying the water system in the concrete?
The independent Eurovent certified test laboratory TNO in Holland is currently investigating this.
It is expected that when the water system is installed within concrete, this will assist for a thermal buffer for up to maximum of a whole week to store and re-use excessive energy. This will be mostly energy from the day / afternoon, which can and will be successfully re-used in the next morning for warming up.
23. Does the Colt-Caloris system affect BREEAM ratings?
BREEAM has two areas where Caloris has an effect:
Firstly, energy uses. If air conditioning is to be used then BREEAM ratings are affected by system efficiency so an energy efficient system like Colt-Caloris will help.
Secondly, ozone depletion. BREEAM ratings are affected by the ozone depletion potential (ODP) of any refrigerants used. The Caloris system has zero ODP.
24. When determining the pipe-work design, what is the affect of using a 'daisy chain' rather than specific pipe-work runs to each unit from a common riser and manifold?
There will be no performance effect, however, like other systems, there will be a requirement for a suitably sized water vessel/buffer when installing a 'daisy chain' pipe-work installation.
The decision as to which pipe-work design is more suitable will be a function of the project requirements, and needs to be determined by the pipe-work designer in coordination with your Colt Sales Consultant.
25. With regards to water quality and treatment, what filtration and dosing measures have to be taken for the water within the closed water system?
Water treatment is not essential if plastic pipe-work is used. However the Colt-Caloris water system must not be contaminated by impure water.
Basic sensible precautions are required to ensure that the cleanliness of the water system is maintained in order to ensure satisfactory long-term operation.
See the unit specification.
These include:
- Ensure that the water system is thoroughly flushed through before any units are re-connected to the system. If possible, incorporate large bore drain valves at the bottom of the risers so that a high rate of flow can be maintained. Back flush unit connections or provide flushing between flow and return.
- Filters and dirt pockets should be provided and cleaned out frequently during the first few months of operation.
- No matter how clean the flushing water when it exits from the drain valves, further corrosion may occur because fresh dissolved oxygen is introduced with each flushing. It is therefore essential that the pipe-work be passivated before the final flushing. Again, plastic piping is recommended.
- With a steel pipe system, and especially if existing pipe-work is to be re-used, specialist services should be used to acid wash, passivate, and flush the system prior to connection of any Caloris units.
- The system needs to be vented in several locations.
- If applicable, regular testing should be carried out to ensure that the pH value and treatment levels are being maintained. The presence of gases in the water could be a danger signal and expert advice should be sought.
26. How does the weight and space of the Colt primary heat pump compare to similar VRF installation requirements?
The Colt-Caloris requirements are marginally better; unit weight and footprint size smaller if anything.
27. How much water is typically required for the system?
Although project specific, a guide would be max. 2000 L of water for a system of at least 100kW, to be supplied via the water system or water vessel.
28. With TAS Modelling, what is the standard energy usage kWhr/m2/annum?
Colt are currently investigating and implementing an energy usage survey by an independent party. Initial findings are circa 80-100 kWhr/m²/annum.
29. How do you determine the size of the Colt primary heat pump?
The primary heat pump size is determined by a selection programme, on the worst case scenario for the building water system at certain times. It is therefore not the same as the total room unit requirement, but indicatively 15% less.
30. What control systems are available for the units?
The units can be controlled via either analogue or state of the art digital controls, with BMS as a standard plug-in card for the main PCB.
The internal controls form part of the Caloris unit, so we require a performance signal only. Suitable attractive thermostats with modern functionality are available to control up to six master and slave units. The slave units can still respond individually to internal sensors but will stay in the mode of the master.
All units are equipped with several external ways of communication, such as remote controls, alarms, inputs and outputs.
31. What is the minimum economic size of installation?
Generally the system is economic with a minimum number of 20 units.
32. Can the Colt-Caloris system be integrated with the primary air provision (via an AHU), to further maximise energy efficiency and reclaim?
Yes, by incorporating special heat exchangers, in an AHU, giving you a 90% sensible efficiency in energy heat reclaim. So the return air and supply air are both going in counter-flow inside the double deck AHU.
There is no water or coil involved at all, either in summer or winter. There are no valves or even heat exchangers with chilled or warm water towards the AHU present. On the contrary, this system is totally self-adjusting.
There are no moving parts only the fans. Colt are able to offer this AHU system as part of the equipment supply.
33. The reversing valve on the units supplied by other water source heat pumps and VRF are renowned for being noisy when they change over from cooling and heating - is Caloris the same?
The Colt-Caloris units use standard reversing valves; however, the valve is enclosed within the double compressor box housing, which provides more than sufficient attenuation.
34. Is there an installation that we can come and see?
Yes, we would be pleased for your design team to visit our demonstration installation at Colt UK, Havant, near Portsmouth where we can also show production line and test facilities.
35. Does the system require primary fresh air to be provided?
Of course fresh air is required for any occupied space, and thus can be provided in the traditional manner.
36. Do you have to use the Colt primary heat-pump?
The Colt heat-pump has been designed for the Colt-Caloris system. If you have an existing or suitable and planned alternative means to inject or reject the energy then this can be utilised. For instance, on a hotel development, the large boiler requirement can be used, supplemented with a chiller to provide the heat rejection.
37. Do you have to use plastic pipe-work?
No. You can use more traditional materials, however the general benefits with plastic is corrosion resistance, cleaner fixing, long life and since you do not need to insulate, thereby saving more time and money.
38. Is there any restriction on the size, length or distance for the system?
No.
39. Can the Colt-Caloris system benefit from 'free-cooling/heating' on the outdoor unit?
Yes, because of the operating temperatures (20-25°C) it is ideal to benefit from free cooling.
40. How does the Caloris system fit in with the Part L Building Regulations 2006, including SBem, IES & TAS calculations?
Again because of its low energy consumption the Caloris fares well, but it does need to be carefully monitored as SBem does not lend itself to adaptation to different systems. We would be pleased to assist with this. We aim to assist IES & TAS to enable their systems to model the unique Caloris system.
| © 2008 Colt International Licensing Ltd - People Feel better in Colt conditions |
| |
Top |
| |
Back |
| |
 Print |
