sometimes we are confused in choosing the size of refrigerators that we will buy for our homes. not everyone wants a big refrigerator or a small refrigerator. for those who have a big house, not a problem memililih large fridge, but for a small house, definitely want a small but versatile refrigerator.
Designing
Designing does not just mean the looks of your refrigerator but also the storage parts it provides to you internally. You are able to check for the storage shelves and compartments it provides and compare them with your wants. Many refrigerators today provide with apart multi utility cabinets and sub divisions in the existing ones for more convenient storage. You can also take from top freezer or bottom freezer compartment and even opt for a separate pull out door vegetable tray at the bottom.
Appears
Externally also there's a wide variety to choose form. You can stick to a single door refrigerator for basic needs. However if you do want to explore and get something off beat, you could have a tough time selecting. The humble single door refrigerator has not only evolved into a double door one but also into ones with large French doors with options like an external water dispenser and even an LCD TV screen. Other than that, they come in attractive pastel as well as metallic colors and even wonderful print motifs. You are able to take your pick and even co ordinate it with the interiors of your living space!
Freezer
Additional important thing to decide is the freezer compartment. People get lured by a large, separate freezer and most of the time end up not using it except for making ice. So if you are not the kind of person who needs to store a lot of frozen foods, avoid getting tempted by a big freezer and choose a fridge with a good refrigerator to freezer ratio.
Space
You also need to consider the space where you will install your refrigerator. Ideally a refrigerator is placed in the kitchen or in the dining area. You need to find out how much space can you dedicate to your fridge from the existing layout. A large refrigerator in a small kitchen would only make things more difficult. So either create ample space for the large refrigerator that you are going to bring home or just stick to a size proportionate to your space.
After making these considerations you need to make on your part before buying a refrigerator, you can go through what is available in the market to choose from. You can check the types of refrigerators and the features that are being provided and decide what you want from your refrigerator. Other than the basics, there are also a few 'extras' that might interest you if you are willing to spend a larger share of your pocket. Here is a
quick rundown on what is up for grab in the current refrigerator market for you to choose from.
Types of Refrigerators
Technologically, there are two types of refrigerators. - Direct Cool and Frost Free. Direct Cool are the single door refrigerators while the Frost Free ones come in multiple doors. Apart from that, depending on the consumer needs, different sizes and design types of refrigerators have come into the market. Your first step should be to decide your usage pattern and find out the type of refrigerator you want.
Single Door Refrigerator
Description: These are the basic, small size refrigerators with a single door and in built freezer compartment on the top. They come in a compact size( 50liters - 100 liters) acting as mini refrigerators and also in a small family size (170liters - 200 liters). These refrigerators are 'direct cool' ones as opposed to the double door refrigerators which are generally 'Frost Free' ones.
Ideal For: Bachelors and small families who have limited storage needs from the refrigerator and also do not require a large freezer.
Top Freezer, Double Door Refrigerator
Description: These Refrigerators have separate doors for the freezer and the refrigerator compartments. They have the freezer compartment on top and have gained immense popularity over the last few years.
Ideal For: Midsized families and people who use the freezer to store frozen foods. Provide easy and direct access to food for people with short height and children.
Bottom Freezer, Double Door Refrigerator
Description: These are again double door refrigerators with the exception of having the freezer compartment at the bottom. The double door refrigerators of both kinds, with top or bottom freezer are medium size refrigerators and come in the size of 200 liters- 450 liters.
Ideal For: Mid sized families and people who do not use the freezer often. These type of refrigerators provide easy access at an eye level to the refrigerated food and save a lot of 'searching' trouble.
Lifestyle Refrigerators
Description: These are large size (450 liters-800 liters) refrigerators with either two or multiple doors. They come with a plethora of features and designer looks and are high priced also.
Ideal For: These refrigerators are for you only if you have a really large family and a big budget too. If you are the kind of person who likes to throw big parties often and has different types of frozen/ refrigerated foods to store and beverages to chill then you must look at this category of refrigerators.
Feature Perfect
Once you are done with sorting out your needs from a refrigerator and the ideal size for your family, you might want to have a look at the many features that the refrigerators of today are providing so that when you go out looking for your perfect fridge, you know what you want and what you don't.
Child Lock: Secures your refrigerator from unwanted opening and closing
Deodorizer and Freshonizer: removes bad odor and keeps food fresh by killing harmful bacteria in the fridge.
Open Door Alarm: Rings an alarm if the door is left ajar for long
Freezer Lamp: Gives illuminated freezer to save you fumbling in the dark
Quick Freeze: makes ice much faster than the normal time taken
Ice and Water Dispenser: A separate water/ice dispenser is provided externally for convenience
Temperature Control Shelves: These are shelves which can be set to a temperature different from the rest of the fridge.
Auto Defrost: Defrosts automatically saving you the hassle.
Auto Power Save: Detects your absence due to zero fridge operations till a certain time and switches itself to power save mode automatically.
Multi Media Features: Cool features like an LCD screen or a digital picture frame attached to your refrigerator door are soon becoming a commonplace in the lifestyle refrigerators. The future will
Adjustable Shelves and Separators: There are door bins that can be removed to create room for taller bottles and jars. Separators on the other hand help you store food items separately from each other.
Purchasing a icebox at the end of the day should not be a decision made in haste. It should be a well thought over one that would give you a commodity that is the most useful to you in every aspect. Think over your lifestyle and food habits carefully and finalize a refrigerator that suits your needs perfectly.
Now you can buy refrigerator compatible with you'r wants.
Monday, May 31, 2010
Reference marine refrigerator or boat refrigeration
when we sailed, of course we want the conditions as comfortable as possible. we want our boat like our own home, all complete, so shipping becomes more comfortable and enjoyable. we can enjoy hot drinks, cold, and others. So we need tools that can meet those needs. one of them is a refrigerator that can be taken to sail. corang but for the layman. There certainly is not knowing jaika refrigerators that can be brought to sail, they just imagine a large refrigerator which only takes place. despite the much cooler that can be taken anywhere, such as boating or marine refrigeration
make for marine refrigerator work. The major components of a DC refrigeration system include the refrigerator, a compressor, and a electrical condenser, a cooling system for condenser, and a plate or plates inside the refrigeration package.
The compressor is part of a closed loop pumping refrigerant through the system and through the evaporator plate in the ice box. The compressor has two sides the High side or discharge side. The discharge side pumps refrigerant under pressure to the condenser. The suction side or low side and sucks refrigerant after it passes thru the evaporator plate back to the compressor. The cold plates in the fridge space have either expansion valves or capillary tube that separate the low and high pressure sides of the refrigeration system.
The refrigerant in the compressor starts as a gas. The compressor compresses the refrigerant gas, from low pressure to high pressure between 100-150 psi. When the pressure is increased like this its temperature is raised dramatically. This hot high pressure refrigerant is then fed to a condenser, where it is cooled and turned into a liquid. The condenser is cooled by either air or water. The refrigerant is now a cool high pressure liquid and is fed to an evaporator plate inside the boats refrigerator box.
The evaporator plate takes the refrigerant from the condenser and here it boils rapidly & evaporates back to a gas, at a very low temperature. This change of state absorbs vast amounts of sensible heat from the evaporator which in turn removes heat from the insulated refrigeration box, thereby lowering its temperature. The BTU is the measurement of heat removed. From the evaporator plate the refrigerant is returned to the low side of the compressor, to start the process again.
Evaporator or Holding Plates
Marine refrigeration systems use either an evaporator plate or a holding plate in the boats refrigeration space or freezer space. Each type of plate works differently in drawing heat from the boats refrigerator and ice box space.
Marine Evaporator
Marine Evaporators are just as if the ones found in household refrigerators. They can get quite cold (thermostat setting) and many evaporators have the ability to make ice next to the evaporator plate or inside the evaporator box. Evaporators come in several shapes and sizes; they can be horizontal plate's vertical plates and rolled plates. Evaporators are constant cycling, or short cycle. Most use a Danfoss marine compressor with H134 refrigerant.
Thermostat controlled evaporator temperature. Turn to lower ice box temperature. Evaporator plates are less expensive, but need Constant power supply.
Marine Holding plates
Marine Refrigerator Holding Plates act like large freezes of ice and the cold temperature of the holding plate sucks heat out of the boats refrigeration box. Holding plates can keep ice boxes cold for long periods.
The main advantage of a holding plate over an evaporator is that they only need to be recharged 1 or 2 times per day. This charging can coincide with attaching to shore power, running the engine and so the refrigerator does not rely on the battery bank. When incorporated into a properly designed system, holdover plates can significantly reduce average energy consumption. However DC holding plates are also possible. The holding plate is filled with a solution that has a freezing point below 23 degrees F. As the compressor runs, the refrigerant passes through the holding Plates coil, freezing the holding plate solution. The compressor turns of and as the holding plate thaws out, heat is removed from the box.
Powering the Compressor
The power supply to the compressor is one of the key elements of the boats refrigeration system. Refrigeration is one of the largest energy consumers onboard, so the power supply is an important element of the system. Power supplies to marine refrigeration systems include AC, DC, Shore Power, Engine power, and hybrid systems. Hybrids are combinations of say 12 volt and engine drive, or engine and shore power. The whole point in looking at power supply to your boats refrigerator is to couple it into onboard power requirements for all your boats marine systems. If you run a generator much of the time then adding on an AC refrigeration unit may make sense, but unless you do, you would be better at looking at 12 V, engine or shore power.
Power can be decided on how you use your boat. Are you tied up at a dock for much of the time and take days trips. Or do you cruise and spend large amounts of time at anchor. Finally are you Powerboating or Sailing will also influence power supply. Sailing means no charging of batteries or power from the engine. Here a solar panel or wind or towed generator can help replenish batteries. If you spend time at the dock, a DC system has plenty of time to recharge on shore power. If you spend time motoring and at the dock and engine drive with shore assist works well.
AC 110 volt marine refrigeration
These drop in refrigerators are like the one in your home and are commonly seen on larges boats with an abundance of AC power and space. The AC powers the marine compressor, and the condenser is typically air cooled. A reliable AC supply is needed in the form of a generator.
DC marine refrigeration with Evaporator plate
One of the cheapest marine refrigeration system and easiest to install is the 12 v or DC system. Air cooling is the simplest. The DC system combined with an evaporator plate that is thermostatically controlled gives flexibility over cooling requirements. Many 12 volt systems use the Danfoss compressor. With the increased efficiency of the Danfoss compressor, DC refrigeration onboard is getting more efficient, but is still power hungry.
For most boats with a small box, a single 12V compressor, air cooled condenser, with evaporator type plate will be about the cheapest option. The Adler Barbour Cold Machine has been around for around 25 years and provides great refrigeration for small to medium size ice boxes.
Shore powered marine refrigeration
Shore powered systems are made to maintain the boat's ice box at set temperature when the boat is at the dock. They offer less power than direct from an engine drive but since you will be at the dock for a while that is not an issue.
If you use a holding plate and shore powered system you can keep the plate cool while away from the dock for 12 hours or so.
Engine powered marine refrigeration
The idea behind an engine driven compressor system is that the engine gets used anyway for at lest an hour or so. If you are Powerboating this makes sense, if you are sailing calculate how much time you use the engine.
If this is the case an engine drive with a holding plate can draw down the ice box in a short period and after that it can be left for 12 plus hours.
The compressor is run directly off the engine. Belt driven or direct compressor, There are two plates and you can add more, plus ad a separate freezer unit. This creates much power and fast cooling of the holding plate. More power than a 110 volt system. Larger systems and multiple plates are possible. Engine driven systems cost more and also involve a labor higher cost
Condenser Cooling
The marine refrigeration systems condenser needs cooling. This is how the refrigerant gets cooled and turned into a liquid. There are 3 ways to cool the condenser;
Air Cooled
Air cooling simplifies installation plus it does not rely on water or adding thru hulls. It is therefore the cheapest installation. For smaller units air cooling is OK, say 4 cu ft or under 6 cu ft you will get adequate performance. The air cooling unit needs a sufficient supply of re-circulated air for it to work. Ducting and space around the unit will help this.
When you cool by air flow you remove heat from the condenser and ad it to the ambient temperature. The temperature inside of the cabin only has enough capacity to disperse this heat.
Water cooled Condenser
Water cooled compressors will work better in higher ambient temperatures and are more efficient and can be 30% more efficient. Water cooling may be best and is better for larger installs especially if freezer is concerned. Water cooling needs a thru hull and a pump to get the water to the condenser. The most efficient way to cool the condenser
Keel cooler Condenser
The keel cooler or keel condenser requires no thru hull fitting and will not be subject to clogging. The keel cooler is a 3" x 7" bronze plate that mounts on the outside of the hull and it is the condenser heat exchanger. The bronze plates are connected direct to the compressor which is the only moving part in the system. The Keel Cooler is for a box up to a 15 cu ft refrigerator or 5 cu ft freezer. Since all the heat is passed into the water outside the boat it will does not heat up the interior. Since it works without a water pump there is never a pump or strainer to maintain and best of all it is nearly silent in operation.
Refrigeration Compressor & plate Combination
Before we pick a size of marine refrigerator we need to understand what factors are involved in keeping the refrigeration box cool. They are mainly box size, insulation and cooling water temperature, number of people aboard and the temperature you are setting the plates for.
Refrigerator Box Volume
This is obvious, the larger the box the more heat removal is necessary. A larger box will need more BTUs of heat removal. After this basic size issue we have things like, Front opening or top opening. Front opening lets cold air out quickly but does allow you to get to the bottom of the box. Drains, if you had a drain for you ice box plug it. You will not need to drain water out of the ice box and this will only let cold air out and heat in. Gaskets, these are a must and must be properly sealed. A trick to identify if there are gaps in the gasket is to put a piece of paper in between the lid or door and the cabinet and close it. Pull on the paper and you should feel some drag if the gaskets are sealing properly. It comes out easily there is a gap. Get new or better gasket material.
Insulation
Typical insulation to a fridge or freezer is foam insulation like Dow Blue board. The recommendation is for 3-4 inches for refrigeration and 4-6 inches for freezer for medium sized boxes. Foam has an R value of 5 per inch thickness, R being a thermal unit. This means in terms of thermal units 3-4 inches represents 15-20R value for the refrigeration unit, and 20-30 for the freezer.
There are manufacturers of vacuum panel thermal insulation. The Glacier bay Barrier Ultra-R super-insulation at R-50 per inch provides lots of insulation without taking up valuable volume. These panels are vacuum panels and are sealed to work. It is very important that you do not drill through or puncture these panels. These panels are custom made, so you would need to provide the manufacturer, exact sizes with locations for copper plate tubes to enter the box. These are built into the panels.
Water temperature
In the tropics water temperature is a lot warmer then northern climates. For every degree water temperature increases a corresponding 2 % increase in required BTU. If you are in the Atlantic portions of the east coast US, you have some cool sea water temps, but of you then cruise down to the Caribbean you may strain your refrigeration system.
Plate Thermostat
The evaporator plate temperature is set by the thermostat. Dial the box temperature down and the system will have to work harder.
Number of people aboard
More people means the box gets opened more and the heat build up from more people adds to the ambient temperature.
How big a Refrigeration System is required?
To calculate how big a refrigeration or marine freezing unit required, you will need to start with an estimation of the BTU requirements of the box. A simple rule of thumb for estimating the BTUs is based on the box volume.
These BTU estimations are based on these assumptions;
- Insulation has an R value of 30 no leaks.
- Water temperatures are tropical in the mid 80s F.
- 2 people aboard, for each extra person add an additional 1,000 daily BTU
- Top opening box, for a front opening door add 15 BTU/inch of door
BTU estimate on refrigeration volume;
Refrigerator daily heat load; 600 Btu per cu. ft.
Freezer daily heat load; 1200 Btu per cu. ft
Lets look at how this works for the 4 cu ft refrigeration system, using the above formula
4 cu. ft. times 600 = 2,400 Btu.
Two additional people on board = 2,000 Btu.
Total required per day = 4,400 Btu
Choosing 12 volt unit with Evaporator
Match this number to the compressor capabilities, and then calculate amps needed to power the system, and then work on the battery bank capability. Start by using the 4,400 BTU form the above example. The Adler Barbour Cold Machine uses the Danfoss BD50 Compressor is rated at 650BTU / hr based on 25F evaporator temp.
This is well above the 4,400/day we need for the 4 cu ft fridge, using only about 1/3 of the power. We could easily go down the Danfoss DB35.
Amps
To calculate how many amps the system will draw we start by converting BTUs to amps with this formula, using an assumption of 5 BTUs per watt hr of energy used. BTU/5/volts. so say we have 4400 BTUS and 12 volts, 4,400/5/12=74 amp hours/day.
Battery Bank
The Amps needed to power the compressor should be 1/4 of the capacity of the house bank. So for the above 74 amp hours needed multiply by 4 to get recommended house battery capacity = 296 amp hrs
Finish
This days being on the water system means keeping food and drinks cold. 12 volt refrigeration units are becoming more popular with technological advances. Greater compressor efficiency and evaporator technology brings 12 volt cooling to the smallest of boats. so you are now understand how to make boat refrigerator work. have nice shipping..!!!
make for marine refrigerator work. The major components of a DC refrigeration system include the refrigerator, a compressor, and a electrical condenser, a cooling system for condenser, and a plate or plates inside the refrigeration package.
The compressor is part of a closed loop pumping refrigerant through the system and through the evaporator plate in the ice box. The compressor has two sides the High side or discharge side. The discharge side pumps refrigerant under pressure to the condenser. The suction side or low side and sucks refrigerant after it passes thru the evaporator plate back to the compressor. The cold plates in the fridge space have either expansion valves or capillary tube that separate the low and high pressure sides of the refrigeration system.
The refrigerant in the compressor starts as a gas. The compressor compresses the refrigerant gas, from low pressure to high pressure between 100-150 psi. When the pressure is increased like this its temperature is raised dramatically. This hot high pressure refrigerant is then fed to a condenser, where it is cooled and turned into a liquid. The condenser is cooled by either air or water. The refrigerant is now a cool high pressure liquid and is fed to an evaporator plate inside the boats refrigerator box.
The evaporator plate takes the refrigerant from the condenser and here it boils rapidly & evaporates back to a gas, at a very low temperature. This change of state absorbs vast amounts of sensible heat from the evaporator which in turn removes heat from the insulated refrigeration box, thereby lowering its temperature. The BTU is the measurement of heat removed. From the evaporator plate the refrigerant is returned to the low side of the compressor, to start the process again.
Evaporator or Holding Plates
Marine refrigeration systems use either an evaporator plate or a holding plate in the boats refrigeration space or freezer space. Each type of plate works differently in drawing heat from the boats refrigerator and ice box space.
Marine Evaporator
Marine Evaporators are just as if the ones found in household refrigerators. They can get quite cold (thermostat setting) and many evaporators have the ability to make ice next to the evaporator plate or inside the evaporator box. Evaporators come in several shapes and sizes; they can be horizontal plate's vertical plates and rolled plates. Evaporators are constant cycling, or short cycle. Most use a Danfoss marine compressor with H134 refrigerant.
Thermostat controlled evaporator temperature. Turn to lower ice box temperature. Evaporator plates are less expensive, but need Constant power supply.
Marine Holding plates
Marine Refrigerator Holding Plates act like large freezes of ice and the cold temperature of the holding plate sucks heat out of the boats refrigeration box. Holding plates can keep ice boxes cold for long periods.
The main advantage of a holding plate over an evaporator is that they only need to be recharged 1 or 2 times per day. This charging can coincide with attaching to shore power, running the engine and so the refrigerator does not rely on the battery bank. When incorporated into a properly designed system, holdover plates can significantly reduce average energy consumption. However DC holding plates are also possible. The holding plate is filled with a solution that has a freezing point below 23 degrees F. As the compressor runs, the refrigerant passes through the holding Plates coil, freezing the holding plate solution. The compressor turns of and as the holding plate thaws out, heat is removed from the box.
Powering the Compressor
The power supply to the compressor is one of the key elements of the boats refrigeration system. Refrigeration is one of the largest energy consumers onboard, so the power supply is an important element of the system. Power supplies to marine refrigeration systems include AC, DC, Shore Power, Engine power, and hybrid systems. Hybrids are combinations of say 12 volt and engine drive, or engine and shore power. The whole point in looking at power supply to your boats refrigerator is to couple it into onboard power requirements for all your boats marine systems. If you run a generator much of the time then adding on an AC refrigeration unit may make sense, but unless you do, you would be better at looking at 12 V, engine or shore power.
Power can be decided on how you use your boat. Are you tied up at a dock for much of the time and take days trips. Or do you cruise and spend large amounts of time at anchor. Finally are you Powerboating or Sailing will also influence power supply. Sailing means no charging of batteries or power from the engine. Here a solar panel or wind or towed generator can help replenish batteries. If you spend time at the dock, a DC system has plenty of time to recharge on shore power. If you spend time motoring and at the dock and engine drive with shore assist works well.
AC 110 volt marine refrigeration
These drop in refrigerators are like the one in your home and are commonly seen on larges boats with an abundance of AC power and space. The AC powers the marine compressor, and the condenser is typically air cooled. A reliable AC supply is needed in the form of a generator.
DC marine refrigeration with Evaporator plate
One of the cheapest marine refrigeration system and easiest to install is the 12 v or DC system. Air cooling is the simplest. The DC system combined with an evaporator plate that is thermostatically controlled gives flexibility over cooling requirements. Many 12 volt systems use the Danfoss compressor. With the increased efficiency of the Danfoss compressor, DC refrigeration onboard is getting more efficient, but is still power hungry.
For most boats with a small box, a single 12V compressor, air cooled condenser, with evaporator type plate will be about the cheapest option. The Adler Barbour Cold Machine has been around for around 25 years and provides great refrigeration for small to medium size ice boxes.
Shore powered marine refrigeration
Shore powered systems are made to maintain the boat's ice box at set temperature when the boat is at the dock. They offer less power than direct from an engine drive but since you will be at the dock for a while that is not an issue.
If you use a holding plate and shore powered system you can keep the plate cool while away from the dock for 12 hours or so.
Engine powered marine refrigeration
The idea behind an engine driven compressor system is that the engine gets used anyway for at lest an hour or so. If you are Powerboating this makes sense, if you are sailing calculate how much time you use the engine.
If this is the case an engine drive with a holding plate can draw down the ice box in a short period and after that it can be left for 12 plus hours.
The compressor is run directly off the engine. Belt driven or direct compressor, There are two plates and you can add more, plus ad a separate freezer unit. This creates much power and fast cooling of the holding plate. More power than a 110 volt system. Larger systems and multiple plates are possible. Engine driven systems cost more and also involve a labor higher cost
Condenser Cooling
The marine refrigeration systems condenser needs cooling. This is how the refrigerant gets cooled and turned into a liquid. There are 3 ways to cool the condenser;
Air Cooled
Air cooling simplifies installation plus it does not rely on water or adding thru hulls. It is therefore the cheapest installation. For smaller units air cooling is OK, say 4 cu ft or under 6 cu ft you will get adequate performance. The air cooling unit needs a sufficient supply of re-circulated air for it to work. Ducting and space around the unit will help this.
When you cool by air flow you remove heat from the condenser and ad it to the ambient temperature. The temperature inside of the cabin only has enough capacity to disperse this heat.
Water cooled Condenser
Water cooled compressors will work better in higher ambient temperatures and are more efficient and can be 30% more efficient. Water cooling may be best and is better for larger installs especially if freezer is concerned. Water cooling needs a thru hull and a pump to get the water to the condenser. The most efficient way to cool the condenser
Keel cooler Condenser
The keel cooler or keel condenser requires no thru hull fitting and will not be subject to clogging. The keel cooler is a 3" x 7" bronze plate that mounts on the outside of the hull and it is the condenser heat exchanger. The bronze plates are connected direct to the compressor which is the only moving part in the system. The Keel Cooler is for a box up to a 15 cu ft refrigerator or 5 cu ft freezer. Since all the heat is passed into the water outside the boat it will does not heat up the interior. Since it works without a water pump there is never a pump or strainer to maintain and best of all it is nearly silent in operation.
Refrigeration Compressor & plate Combination
Before we pick a size of marine refrigerator we need to understand what factors are involved in keeping the refrigeration box cool. They are mainly box size, insulation and cooling water temperature, number of people aboard and the temperature you are setting the plates for.
Refrigerator Box Volume
This is obvious, the larger the box the more heat removal is necessary. A larger box will need more BTUs of heat removal. After this basic size issue we have things like, Front opening or top opening. Front opening lets cold air out quickly but does allow you to get to the bottom of the box. Drains, if you had a drain for you ice box plug it. You will not need to drain water out of the ice box and this will only let cold air out and heat in. Gaskets, these are a must and must be properly sealed. A trick to identify if there are gaps in the gasket is to put a piece of paper in between the lid or door and the cabinet and close it. Pull on the paper and you should feel some drag if the gaskets are sealing properly. It comes out easily there is a gap. Get new or better gasket material.
Insulation
Typical insulation to a fridge or freezer is foam insulation like Dow Blue board. The recommendation is for 3-4 inches for refrigeration and 4-6 inches for freezer for medium sized boxes. Foam has an R value of 5 per inch thickness, R being a thermal unit. This means in terms of thermal units 3-4 inches represents 15-20R value for the refrigeration unit, and 20-30 for the freezer.
There are manufacturers of vacuum panel thermal insulation. The Glacier bay Barrier Ultra-R super-insulation at R-50 per inch provides lots of insulation without taking up valuable volume. These panels are vacuum panels and are sealed to work. It is very important that you do not drill through or puncture these panels. These panels are custom made, so you would need to provide the manufacturer, exact sizes with locations for copper plate tubes to enter the box. These are built into the panels.
Water temperature
In the tropics water temperature is a lot warmer then northern climates. For every degree water temperature increases a corresponding 2 % increase in required BTU. If you are in the Atlantic portions of the east coast US, you have some cool sea water temps, but of you then cruise down to the Caribbean you may strain your refrigeration system.
Plate Thermostat
The evaporator plate temperature is set by the thermostat. Dial the box temperature down and the system will have to work harder.
Number of people aboard
More people means the box gets opened more and the heat build up from more people adds to the ambient temperature.
How big a Refrigeration System is required?
To calculate how big a refrigeration or marine freezing unit required, you will need to start with an estimation of the BTU requirements of the box. A simple rule of thumb for estimating the BTUs is based on the box volume.
These BTU estimations are based on these assumptions;
- Insulation has an R value of 30 no leaks.
- Water temperatures are tropical in the mid 80s F.
- 2 people aboard, for each extra person add an additional 1,000 daily BTU
- Top opening box, for a front opening door add 15 BTU/inch of door
BTU estimate on refrigeration volume;
Refrigerator daily heat load; 600 Btu per cu. ft.
Freezer daily heat load; 1200 Btu per cu. ft
Lets look at how this works for the 4 cu ft refrigeration system, using the above formula
4 cu. ft. times 600 = 2,400 Btu.
Two additional people on board = 2,000 Btu.
Total required per day = 4,400 Btu
Choosing 12 volt unit with Evaporator
Match this number to the compressor capabilities, and then calculate amps needed to power the system, and then work on the battery bank capability. Start by using the 4,400 BTU form the above example. The Adler Barbour Cold Machine uses the Danfoss BD50 Compressor is rated at 650BTU / hr based on 25F evaporator temp.
This is well above the 4,400/day we need for the 4 cu ft fridge, using only about 1/3 of the power. We could easily go down the Danfoss DB35.
Amps
To calculate how many amps the system will draw we start by converting BTUs to amps with this formula, using an assumption of 5 BTUs per watt hr of energy used. BTU/5/volts. so say we have 4400 BTUS and 12 volts, 4,400/5/12=74 amp hours/day.
Battery Bank
The Amps needed to power the compressor should be 1/4 of the capacity of the house bank. So for the above 74 amp hours needed multiply by 4 to get recommended house battery capacity = 296 amp hrs
Finish
This days being on the water system means keeping food and drinks cold. 12 volt refrigeration units are becoming more popular with technological advances. Greater compressor efficiency and evaporator technology brings 12 volt cooling to the smallest of boats. so you are now understand how to make boat refrigerator work. have nice shipping..!!!
Friday, May 28, 2010
FURminator deShedding Tool
Product Features
* Innovative grooming tool for long- and short-haired dogs and cats
* 4-inch stainless-steel edge quickly and easily removes loose undercoat hair
* Decreases shedding up to 90 percent for about 4 to 6 weeks
* Leaves a shiny and healthy topcoat; comfortable, ergonomic grip handle
* Measures 6 by 1 by 4-1/8 inches
product detail
* Innovative grooming tool for long- and short-haired dogs and cats
* 4-inch stainless-steel edge quickly and easily removes loose undercoat hair
* Decreases shedding up to 90 percent for about 4 to 6 weeks
* Leaves a shiny and healthy topcoat; comfortable, ergonomic grip handle
* Measures 6 by 1 by 4-1/8 inches
product detail
Thursday, May 27, 2010
GE SmartWater MWF Refrigerator Water Filter
Product Description
From the Manufacturer
GE MWF Refrigerator Water Filter is easy to replace with no special tools required. No need to even turn off the water, simply turn the filter to the left to remove. A check valve stops water flow and prevents leakage. Insert a new filter and turn to the right. It replaces GE water filter part numbers GWF, GWFA, GWF01, GWF06, MWFA, and Hotpoint HWF, HWFA . This GE water filter works with a wide-range of GE and Hotpoint models and should be replaced every six months. An adapter may be needed if you have the following filters: FXRC, FXRT, MXRC, HXRT, WR97X10006, and Kenmore 46-9905.
Product Description
The General Electric (GE) MWFDS SmartWater Refrigerator Filter reduces lead cysts, asbestos, mercury, and other sediments and pesticides as well as tastes and odor from chlorine treatment for better tasting and healthy water. The filter is NSF tested and certified
Product Details
From the Manufacturer
GE MWF Refrigerator Water Filter is easy to replace with no special tools required. No need to even turn off the water, simply turn the filter to the left to remove. A check valve stops water flow and prevents leakage. Insert a new filter and turn to the right. It replaces GE water filter part numbers GWF, GWFA, GWF01, GWF06, MWFA, and Hotpoint HWF, HWFA . This GE water filter works with a wide-range of GE and Hotpoint models and should be replaced every six months. An adapter may be needed if you have the following filters: FXRC, FXRT, MXRC, HXRT, WR97X10006, and Kenmore 46-9905.
Product Description
The General Electric (GE) MWFDS SmartWater Refrigerator Filter reduces lead cysts, asbestos, mercury, and other sediments and pesticides as well as tastes and odor from chlorine treatment for better tasting and healthy water. The filter is NSF tested and certified
Product Details
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