FAQ

General

• How can I choose the right CW-30 model?

  Use the model selection guide. When determining the correct configuration, make sure that the model chosen allows for:

  1. the simplest duct pattern (to minimize static losses and noise),
  2. the shortest supply duct run (to minimize heat gain), and
  3. easy access to the control access panel.

• What is the lead time for a CW-30?

  While most orders are shipped within a week of receipt of a purchase order, please allow a maximum of three weeks for order processing. Shipment time ranges between three to ten business days depending on destination.

• What size of room will the CW-30 cool effectively?

  Various factors such as level of insulation, amount and type of glazing used, and air-tightness of treated space affect the size of room that can be cooled effectively. A single CW-30 can cool a space up to 2000 cubic feet in volume as long as it is airtight, properly insulated (R20) and has a small amount of glazing.

• Is there a model with a higher cooling capacity?

  No. If a cellar is large enough to require a higher cooling capacity, the value of the contents of the treated space is substantial enough to merit redundancy in the case of equipment failure. Therefore, the installation of multiple units is a preferred solution.

• What advantages does a CW-30 have over a through-the-wall air-cooled system?

  Air-cooled systems usually require wall openings to adjacent rooms inside the home into which they reject great amounts of heat, especially during the summer months, resulting in decreased efficiency during peak operation as the system attempts to vent heat into an already hot environment. If the adjacent room is a living space, the occupants may complain due to the excess heat and unwanted noise produced by such a system. Vibration transmission through supporting walls to the stored product can also make this type of system an undesirable option. Unlike air-cooled systems, the CW-30 does not reject heat into any adjoining space since it does not require air venting. There is no need for any wall openings if the unit is installed within the treated space. This feature generally reduces noise, reduces vibration transmission to the stored product, and allows more flexibility for unit placement resulting in a more aesthetic solution. Since the CW-30 is a water cooled system, its efficiency is not affected by ambient air temperature as is true of air-cooled systems – it will always operate at peak efficiency.

• What advantages does a CW-30 have over a split system?

  Split systems are costly to install since they require a refrigeration technician to install refrigeration lines, evacuate the system and then charge it. Onsite split system installations do not allow for the same level of factory testing and quality control. Further, split systems are not suited for quick replacement; they must be serviced onsite by a refrigeration technician.

• What is the BTU rating of the CW-30?

  Designers often try to determine the anticipated heat gain of a space in order to find an appropriately sized cooling unit, but they should be aware of two factors. First, heat gain calculation methods in current use cannot accurately model heat gains for small spaces such as wine cellars. Second, there currently are no North American standards for testing cooling capacity of wine cellar refrigeration equipment. So while a manufacturer can claim that their equipment has a certain capacity, the test conditions may be different from that used by another company. The CW-30 has a capacity of approximately 4000 BTUH (tested at a return air temperature of 55°F and a suction pressure of 35 PSI).

• What is the ideal humidity level for a wine cellar?

  Research indicates that relative humidity levels between 40% and 60% not only allow for a healthy environment for humans but also prevent mold and mildew from damaging paint, wood, drywall, a variety of fabric, cardboard, corks, and bottle labels. Since a higher level of relative humidity is desired for wine maturation, the ideal humidity level of a wine cellar should be approximately 60%.

• Can the CW-30 humidify?

  The CW-30 passively controls humidity to 60% Relative Humidity (RH) at 55°F. This technique of humidity control can be effective even in dryer climates since RH rises as temperature drops. For example, if a room starts off at 75°F and 30% RH and then has its temperature dropped to 55°F with minimal dehumidification (which the CW-30 is capable of doing), the final RH level will be close to 60% without the addition of a single drop of water. However, since the conditions outside this room are much drier, the tendency will be for moisture to permeate out of the room. Even the best of vapor barrier systems cannot prevent this moisture transfer. Wine cellars that have low RH are generally a result of low RH within the home environment. If the RH in the home is within 40-60% (the recommended range for a healthy environment for humans), the wine cellar should maintain a suitable RH level without the need for humidification within the cellar. Therefore, M A N Systems recommends that if humidification is needed, it should be added to the entire home environment rather than solely to the wine cellar. If the desire is to provide humidity directly to the wine cellar, a stand alone humidifier can be installed (M A N Systems recommends steam generating humidifiers).

• Other companies offer a liquid (bottle) temperature sensor. Why is this feature not available with the CW-30?

  Due to the high specific mass of the wine compared to air, wine will adjust very slowly to any changes of air temperature. For example, while the air temperature may fluctuate by five degrees within a short period of time (such as when an occupant enters the room), the temperature of the wine will respond to this change in air temperature very slowly. If the sensor is in the air, the unit will begin operation immediately to offset the load and the wine temperature will not fluctuate at all. However, if the sensor is in the wine, the wine temperature will fluctuate by at least 1°F (a typical pre-set thermostat differential) before the equipment begins to operate. The objective of wine storage is to prevent unnecessary fluctuations of the wine temperature; therefore, a liquid sensor fails to do so. Further, since the response time for a temperature change in the wine bottle is very long (due to its specific mass), the air temperature in the wine cellar will drop much lower than setpoint before the wine reaches the desired temperature. A cooler wine cellar temperature results in a higher amount of heat loss which decreases efficiency. Cooler wine cellar temperatures will also result in an excessive and unnecessary amount of dehumidification due to a lower evaporator temperature. Therefore, having the immersed sensor is not only ineffective, but also inefficient. While it is true that a system that senses air temperature rather than wine temperature will cycle more often, moderate cycling of a well designed and constructed unit will not affect its operational integrity.

Installation

General

• Does the cooling unit need to be installed within the treated space?

  The CW-30W must be installed within the treated space. Any of the seven CW-30M configurations may be installed either within or adjacent to the treated space.

• How far away from the treated space can the CW-30M be installed?

  The unit should be installed in a space adjacent to the treated space. The maximum combined length of supply and return air ducting should not exceed 25’.

• What special installation requirements are there for a CW-30M installed adjacent to the treated space?

  The supply and return air ducts must be insulated with a minimum of R10 wrap or lining. All ducting/duct connections must be sealed.

• Can the cooling unit be installed outdoors?

  The CW-30 is intended for indoor installations only. It should not be installed in an environment subject to temperatures below 4°C (40°F) or temperature and humidity levels exceeding 27°C (80°F) and 70% RH. For applications where the operating environment does not meet these criteria, install the unit within the treated space.

• Can the cooling unit be installed in a mechanical room?

  Yes, as long as the mechanical room is adjacent to the treated space and the temperature and humidity levels of the mechanical room do not exceed 27°C (80°F) and 70% RH. Mechanical rooms with hydronic equipment tend to exceed these limits.

• Can the cooling unit be concealed within millwork?

  Yes. The CW-30W is designed to be concealed within a single depth racking module. The CW-30M is designed for under-counter installations with a minimum depth of 18”.

• Does it matter where the cooling unit is located within the treated space?

  The unit should be located to provide even air distribution within the treated space. The control panel should be fully accessible without having to remove the unit from its installed location.

• Once utilities and ducting are roughed in, what is required for the installation of the CW-30?

  Three water lines are connected to the unit using a small crescent wrench, the power cord is plugged into a receptacle and the thermostat harness is plugged into the unit. Final duct connections, if required, are made and the unit is ready for operation. The CW-30 can be connected or disconnected and removed within minutes.

• Do I need a refrigeration technician to install the CW-30?

  No.

• Do I need to make any setting adjustments to the CW-30?

  No. This unit has been thoroughly tested and pre-set to operate at desired settings. Any changes made (including the addition of refrigerant) that are not authorized by M A N Systems will void the warranty.

• Are there any special requirements for the cooling units I should be aware of?

  Always keep the unit upright, protect from freezing, protect from construction dust and do not operate until construction is complete.

• Does the unit need to be level?

  Yes.

• Does the control panel need to be accessible for normal operation?

  Yes. A minimum of 12” service access is recommended on the control panel side.

• What clearances do I need to install a CW-30?

  Please refer to the shop drawings.

Thermostat

• Where should I install the thermostat?

  Choose a location within the treated space that will not be directly affected by the supply airstream.

• What do I need to install the thermostat?

  20’ of 18/2 stranded conductor is supplied with a harness connection that plugs into the CW-30. The thermostat can either be mounted directly on a wall or with a flush mounted vertically oriented single gang switch box (preferred option). If a longer cable is required or if the thermostat rough-in is to be completed before the CW-30 is on site, use 18/2 stranded conductor and splice on to the supplied harness.

• If I do not want to use the supplied thermostat, what options are there?

  All CW-30 models can be controlled by any controller or control system (including a building automation control system) with a dry contact output. Contact M A N Systems for other custom control options.

Ducting

• Do I need a ducted air return if my CW-30M is installed adjacent to the treated space?

  Yes.

• Do I need a ducted air return if my CW-30 is installed within the treated space?

  No. However, a minimum clearance of six inches is required between the air return opening on the unit and any adjacent wall or millwork. An air path to the return air opening of the unit with a minimum free area of 80 sq. in. must also be provided.

• Where should the supply and return air ducts for a CW-30 be installed?

  The supply air grille/opening should be as close to the ceiling as practical or designed to discharge air toward the ceiling. The return air should draw from as close to the floor as possible. Supply air must be ducted and discharged a minimum distance of four feet away from the return air grille to prevent short-cycling. In some cases, supply and return air can both be located at the ceiling level, but special care must be given to prevent short-cycling.

• How do I size the ducting for the CW-30?

  Choose one of the following duct sizing methods:

  1. Use optional duct kits offered by M A N Systems.
  2. Quick duct sizing method: All ducting must have a minimum cross-sectional free area of 80 sq. in. Since the supply air opening is only 6” Ø a duct increaser must be installed at the supply air collar of the unit. Return and supply duct runs must not exceed a combined total of 25’ in length.
  3. Detailed duct sizing method: Qualified engineers or designers can use the fan performances below for custom duct sizing solutions.

  CW-30M FAN PERFORMANCE (COIL PRESSURE DROP = 0.3; DESIGN AIRFLOW = 400 CFM)
  STATIC PRESSURE (INCHES WATER)	0	0.24	0.77	1.51	2.06
  AIRFLOW (CFM)	450	444	420	374	303

  CW-30W FAN PERFORMANCE (COIL PRESSURE DROP = 0.15; DESIGN AIRFLOW = 300 CFM)
  STATIC PRESSURE (INCHES WATER)	0	0.12	0.37	0.85	1.32
  AIRFLOW (CFM)	330	317	300	280	244

• What size should the supply and return air grilles be?

  The CW-30W requires a supply air grille with a minimum area of 120 sq. in. If a return air grille is used it should be directly in front of and match the size of the return air opening of the unit. The CW-30M requires a supply and return air grille with a minimum area of 144 sq. in. Grilles should have a minimum of 50% free area.

• How can I reduce noise?

  Noise caused by vibration transmission can be dampened by using flexible ducting/connectors. Air/fan generated noise can be dampened by using acoustic duct lining.

Electrical & Plumbing Requirements

Electrical

• What type of power supply is required?

  Provide a receptacle on separate circuit at point of installation (unit is not hard-wired). For a 115/1/60 power supply, provide a dedicated 15 Amp circuit breaker. For 230/1/50 power supply (European market only), provide a dedicated 10 Amp circuit breaker.

• Can I plug the cooling unit into an existing receptacle?

  Yes, as long as the receptacle is on a dedicated 120 VAC 15-amp circuit (North American market).

• Can I use an extension cord (for power supply)?

  No.

• Is a 220 VAC model available for North America?

  No this option is only available for the European market.

Plumbing

• What plumbing requirements are there?

  Three ¼” FPT plumbing connections (refer shop drawings for location) are required as follows:

  1. One water supply connection (labeled as “Water In” on the unit).

     For domestic cold water applications: Install a water shut-off valve near the unit. Pressure should be regulated to a maximum of 80 PSI. A minimum water pressure of 15 PSI is required for units having gravity drains. Otherwise, add loss of piping and head of drain line to calculate required water pressure (this calculation is not necessary if unit is operating under full city water pressure). Please consult with the local authority having jurisdiction to see if local laws require the installation of a type of backflow preventer (such as RPBAs) which is sometimes required when cooling equipment is connected to the domestic cold water supply. (Please also read the answer given to the question below: “Is the use of water-cooled equipment not prohibited by many municipalities?”)

     For closed loop applications: Ensure that inlet water temperature will not exceed 95°F. Do not install a balancing valve – the unit is equipped with an internal water regulating valve to control the head pressure. Flow characteristics: 0.0 gpm when unit is off / 0.25gpm @ 60 °F / 1 gpm @ 95°F, 1 PSI PD). Provide isolation valves near the unit. (Please also refer to a number of answers given below to question that concern closed loop systems.)

  2. One water drain connection (labeled as “Water Out” on the unit). For domestic cold water applications, connect to a main sanitary waste or storm drain line, according to local code (eg. dishwasher type drain connection or a floor drain). If tying in to an overhead drain line, tap into the top end of the pipe to prevent back pressure. Since this line is under city pressure, head of drain line is only limited by city pressure.

  3. One condensate drain connection (labeled as “Condensate Drain” on the unit). Unit is equipped with an internal condensate pump capable of 15’ of head – a gravity drain is not required. DO NOT TIE TWO DRAIN CONNECTIONS TOGETHER. Separately connect to a main sanitary waste or storm drain line, according to local code (eg. dishwasher type drain connection or a floor drain). If tying in to an overhead drain line, tap into the top end of the pipe to minimize back pressure. Line should be brought up high enough (vertically) to allow for a 2% downward slope for the entire horizontal run of the pipe.

  Three ¼” MPT x 3/8” compression elbow fitting adapters are supplied with the unit for ease of installation (use Teflon tape or paste prior to connecting these or any other fittings to unit).

• Do I need a gravity drain for the return water line?

  No.

• Do I need a gravity drain for the condensate water line?

  No. The unit has an internal condensate pump rated for a maximum pressure drop of 15’ (water).

• Can I tie the two drain water lines together at the unit?

  No. They must be individually piped to a gravity drain.

• What type of piping can be used?

  Copper tubing, PEX tubing or the supplied braided stainless steel lines can be used.

• What pipe size is required?

  When a system is connected to a domestic cold water supply, only 3/8” OD tubing should be used for all three water connections and larger sized piping should never be used for either of the two drain connections. When a system is connected to a closed loop system, the local designer should specify the supply and return water line sizes but only 3/8” OD tubing should be used for the condensate drain.

• Can I run the three required water lines together?

  Yes, but the cold water supply and the return water lines should be physically separated from each other to prevent heat transfer from one pipe to the other.

• Do the water lines need to be insulated?

  No. However the supply and return water lines should be separated to prevent heat transmission.

• Do I need to use a water filter?

  A water filter is typically not required. However, in areas with serious water quality issues, it may be practical to use a filter, but regular filter maintenance is required to prevent restricted water flow to the CW-30.

• What is the lowest allowable inlet water temperature?

  There is no lower limit because the unit is equipped with an internal water regulating valve.

• Can the water used by the CW-30 be recirculated?

  Yes, but a local design professional will be required to design an appropriate closed loop system.

• Can the CW-30 be connected to a closed loop system?

  Yes. It can be used with closed loop condenser water, chilled water or geothermal systems as long as entering water temperatures do not exceed 95°F.

• What design requirements are there if a CW-30 is connected to a closed loop system?

  The unit is equipped with an internal water regulating valve to control the head pressure. Expected flow rates will vary between 0.0 usgpm (when unit is off) to approximately 1.0 usgpm (at an entering water temperature of 95°F). Approximate pressure drop at 1.0 usgpm is 1.0 PSI. If a dedicated pump is used, a variable speed pump with built in pressure sensor (eg. Grundfos Alpha pump) may be the simplest way to control the pump. The closed loop system will need to be able to care for a heat of rejection load of 6,000 Btu/hr.

• What are some design considerations where frequent water flow interruptions are expected to occur such as a well water or closed loop system pump shutdown?

  Since the CW-30 has a head pressure safety switch that does not automatically reset, it is advisable to install an external water pressure switch (e.g. Hubbell 69WR* which can be purchased as a special order item directly from M A N Systems) on the inlet water side of the system that is wired in series with the thermostat. When the water pressure drops below setpoint (e.g. due to pump shutdown), the water pressure switch will prevent the CW-30 from turning on which in turn will prevent the head pressure safety switch from tripping. When selecting the external water pressure switch choose a model that has an operating range suitable for the system.

• Is the use of water-cooled equipment not prohibited by many municipalities?

  A number of municipalities have laws prohibiting the use of “once through cooling equipment” and a CW-30 that uses domestic cold water for heat rejection (as opposed to it being part of a closed loop system that recirculates water) fits this description. However, in some cases, these laws apply only to air-conditioning equipment or to cooling equipment that exceeds a certain capacity. Therefore, if you plan to use domestic cold water, it is always recommended that you consult with the local authority having jurisdiction to ensure that there are no local restrictions that apply to the CW-30. If a city official, engineer or contractor makes the claim that the use of the domestic-water-cooled equipment is prohibited, please ask them to provide a specific reference to the law they are referring to and forward this information to M A N Systems so that we can confirm if this restriction applies to the CW-30.

• How much water will the cooling unit use?

  Water usage is dependent upon supply water temperature and how long the equipment needs to operate to maintain the desired temperature. Operating time is affected by a number of factors such as how large and well constructed the treated space is – it is therefore difficult to predict. Water flow rates vary from 0.25 usgpm at an entering water temperature of 60°F up to 1.0 usgpm at 95°F. If domestic cold water (DCW) is used, one can expect flows of about 0.25 usgpm since DCW is typically at or below 60°F, – this is less than 20% the consumption of a typical low consumption shower head. The system has an internal water regulating valve that maximizes equipment performance while minimizing water consumption. When the unit is off, there is no water flow. While there may be concern about costs related to metered DCW use, one must factor in that air-cooled systems are typically less efficient and will have higher electrical operating costs.

Maintenance / Servicing / Warranty

• Does the CW-30 require regular scheduled maintenance?

  No.

• What do I need to do if my CW-30 isn’t working?

  Contact M A N Systems technical support by email and you will be contacted by phone and assisted to troubleshoot and resolve the issue.

• What is the warranty for a CW-30?

  M A N Systems warrants all their equipment to be free of manufacturing defects both as to workmanship and materials for a period of two years from the purchase date, FOB M A N Systems, Surrey, BC, Canada. If the equipment retailer or owner wishes to have the unit inspected and corrected by a local refrigeration contractor, M A N Systems will replace and ship prepaid (four business days air freight within Canada and the continental USA) any defective component, but will not reimburse for any labor charges incurred in the field. However, M A N Systems must be contacted by the field technician while on site so that we can assist with troubleshooting, confirm the issue, and recommend a solution. M A N Systems will determine if the equipment is to be repaired or replaced. Repaired or replacement units will be shipped back to the owner prepaid. Replacement units will be invoiced and a credit will be made for the returned unit only after it has been received and inspected.

  Applicability: This warranty applies only if the equipment

  1. a) is installed in accordance with all instruction sheets provided,
  2. b) is properly and reasonably maintained, and
  3. c) has not been subject to damage or misuse.

  Limitations, Exclusions, Remedies: There are no warranties that extend beyond the descriptions of the face hereof. This limited warranty is in lieu of all warranties, expressed or implied and of all other obligations or liabilities on the part of M A N Systems. There shall be no implied warranty of merchantability. M A N Systems neither assumes nor authorizes any person to assume for it any other obligation or liability in connection with the sales of its products. Damages for breach of this warranty shall not exceed the lesser of the cost of repair or replacement. Repair or replacement shall be the exclusive remedy available to the purchaser. Under no circumstances shall M A N Systems be liable by virtue of this warranty or otherwise for any special, indirect, secondary, incidental, or consequential damage of any nature to any person or property arising directly or indirectly out of the use or inability to use a warranty product, including any actual or perceived damage of wine stored within the cellar.

  Limited Warranty – The Intent: The CW-30 product line is manufactured with the best components the market has to offer. This coupled with CW-30 production experience since 1986 minimizes warranty issues. When issues arise, on site diagnosis of the problem can alleviate costly warranty procedures since most issues can be corrected on site. M A N Systems should be notified of this immediately to ensure technical support will be available during the site visit. A trained retailer or a technician hired by the retailer (at the retailer’s expense unless otherwise approved by M A N Systems) can often isolate and correct the problem within minutes if he is directed over the phone by one of our technical representatives. Should the diagnosis lead to the conclusion that a defective part requires on site replacement, we will ship out a replacement part at our expense so that it can replaced by the retailer or a technician hired by the retailer. M A N Systems will determine whether to cover the labor cost on an individual case basis. Of course, the retailer/customer always has the right to ship (at his expense) any malfunctioning equipment back to M A N Systems for repair within two years of the purchase date. We will cover the cost of all parts and labor should there be a legitimate problem due to a defective component or of some manufacturing fault. M A N Systems will determine on an individual case basis which, if any, of the shipping cost incurred by the retailer/customer will be covered.

• My CW-30 is not under warranty. Who can service my product?

  It is best to contact M A N Systems prior to hiring a service technician. We will offer troubleshooting assistance and provide guidance as to how to best resolve the issue. If it is determined that a refrigeration technician is required, the customer will need to contact a refrigeration company in their locality. M A N Systems is not in a position to make recommendations of companies that can service the CW-30 Series. The refrigeration technician must have experience with R134A (type of refrigerant used in a CW-30). While some technicians may be hesitant to work on equipment they are not familiar with, M A N Systems will offer troubleshooting assistance by phone and recommend where replacement parts can be purchased from. (While parts can also be purchased directly from M A N Systems, at times, it is more cost effective to purchase locally).

Construction of the Treated Space

• Does the floor need to be insulated?

  Slab-on-grade floors in cooler climates do not require under-slab insulation. However, a thermal break must be installed if radiant floor heating is installed in a floor slab adjacent to the wine cellar. This will reduce heat migration through the concrete floor into the treated space. Slab-on-grade floors in warmer climates do require under-slab insulation. Floor insulation is also required if the space below the treated space is heated.

• Does the ceiling need to be insulated?

  Yes, a minimum insulation value of R20 is required. If there is an attic or if radiant floor heating is installed in the space above (ceiling of) the treated space, insulate to a minimum of R38 and provide a thermal break.

• Do the walls have to be insulated?

  Yes, a minimum insulation value of R20 is required.

• Does radiant floor heating of adjacent spaces affect the performance?

  Yes. A thermal break must be installed if radiant floor heating is installed in a floor slab adjacent to the wine cellar. This will reduce heat migration through the concrete floor into the treated space. If radiant floor heating is installed in the space above (ceiling of) the wine cellar the space below the hydronic piping must be thermally broken and insulated to a minimum of R38.

• Does it matter where the cooling unit is located within the treated space?

  The unit should be located to provide even air distribution within the treated space. The control panel should be fully accessible without having to remove the unit from its installed location.

• One of the walls to my wine cellar is all glass, will that effect the performance of the cooling unit?

  Yes, but the use of energy efficient double glazed systems will reduce thermal gain.

• Do I need an exterior grade door?

  Yes. Only exterior grade doors with jamb and threshold seals should be used to limit warm/cold air in/exfiltration.

• How important is it to have an air tight room?

  It is critical – even a very small gap under the door can compromise anticipated equipment performance. Air tightness of the treated space is also critical for humidity control.

• Will the type of lighting within the treated space affect the performance of the cooling unit?

  Yes. Choosing fixtures that emit low IR radiation will minimize cooling requirements.