• Pages

  • Home

• Categories

  • Air Conditioning
  • Company News
  • Heating
  • HVAC information
  • Ventilating

• Recently Written

  • WASTE OIL HEATERS BEAT HIGH FUEL COSTS THIS WINTER
  • Fan Forced Electric Space Heaters for your Garage or Workshop
  • Do I need a Right Hand or Left Hand HVAC Coil?
  • Replacing HVAC Coils 10 Fast Facts
  • Evaporative Cooler Ezine Article

• Archives

  • July 2008
  • June 2008
  • May 2008

• Links

  • 
  • 
  • 
  • XHTML

WASTE OIL HEATERS – BEAT HIGH FUEL COSTS THIS WINTER!
Waste oil heaters and waste oil boilers produce nearly “free” heat while also eliminating the burden of recycling used oil. It gets even better; some states offer tax incentives to heat your facility with waste oil heaters and waste oil boilers!
Waste oil heaters and waste oil boilers are typically fueled with used vegetable oil, recycled oil, used motor oil or used transmission fluid.
Restaurants, auto repair shops, quick lubes and manufacturing facilities generate a surplus of used oil. It is difficult to dispose of waste oil. Tap into this enormous surplus by installing waste oil heaters and waste oil boilers today!

Waste Oil Heaters / Waste Oil Boilers - Commonly Asked Questions:

Is it really free to heat with waste oil? Only if you self-generate a sufficient supply of waste oil. In reality, waste oil heaters still use electricity to power the blower fan. This cost is about 1/60th of the cost to run a comparable clean fuel oil heater.
Most states have waste oil suppliers if you do not generate enough on your own. Waste oil prices range from $.50 to $.90 per gallon delivered. Take a look at the cost of diesel fuel oil the next time you are filling up your vehicle. Fuel oil is estimated to cost $5.49/gallon this winter. Crunch the numbers; the payback for purchasing a waste oil heater is often less than 1 year.

Where can I obtain waste oil? Waste oil cannot be safely dumped into the ground, landfills or waterways. Commercial entities that generate waste oil typically pay a recycler for proper disposal. You can purchase waste oil from recyclers or buy it directly from the source that produces it. The most common waste oil producers are restaurants, quick lubes, automotive repair shops and factories that use hydraulic equipment.

What is the BTU potential of a typical gallon of waste oil? A gallon of waste oil contains 153,000 to 180,000 BTU’s per gallon. For comparison, a gallon of propane fuel will produce 92,000 BTU’s

Are there environmental concerns when burning waste oil? Modern waste oil heaters and waste oil boilers do not produce odors or smoke. Before you purchase a waste oil heater or waste oil boiler, make sure it meets all EPA requirements.

The cons: As with any heating device, there are pros and cons. Waste oil heaters can require more frequent cleaning then a traditional clean fuel oil heater. If you follow the manufacturer’s installation and operation instructions, you shouldn’t run into problems. The money you are saving grossly outweighs the small amount of additional maintenance that may or may not be required.

Warming your garage or workshop can be conveniently accomplished using an electric heater. A fan forced electric space heater is inexpensive to buy, easy to operate, maintenance free, and able to heat areas where other heating solutions might be difficult to install, expensive, or impractical.

Operating Principle
An electric heater converts electrical energy into heat. The heating element inside every electric heater is an electrical resistor which works on the principle of Joule heating: electric current flowing through a resistor converts electrical energy into heat energy.
Air is moved past the heating element by an electric fan. This reduces the thermal resistance between the heating element and the air, allowing heat to be transferred more quickly. The hot air leaves the heater and warms the surrounding area. Heating of a room occurs rapidly, however operation may be noisy.

Common Permanently Mounted Electric Space Heater:

Benefits of a fan forced electric heater in garages or workshops:
 Simple thermostat control.
 Clean heat, no odor, no by-products of combustion.
 Quick heating of enclosed spaces.
 No open flame to worry about.
 High temperature cut-out turns the heater off if it gets too hot.
 No messy fuel oil or dangerous natural gas to contend with.
 100% Efficient.
 No maintenance.
 Very reliable. The only moving part is the easily replaceable motor and fan assembly.
 Louvers direct warm air where you need it most (available on select models).
 Durable. Casing is treated for corrosion resistance.
 Compact and lightweight
 Fast, easy installation.
 Versatile mounting bracket allows attachment to wall and/or ceiling (available on select models).
 Wide range of sizes available to match your heating load.
 Fan only can run in the Summer to help circulate air (available on select models).

Things to consider with a fan forced electric heater in garages or workshops:
 Manufacturer’s recommended clearances from walls, ceilings, and combustible materials must be maintained.
 Must never be used when flammable gases or particles are present in the air.
 Will not operate during a power failure.
 Sound created by fan.
 The circuit feeding the heater must be sufficient to carry the amperage (electricity flow) the heater requires.
 Heater moves air which can kick up dust in your garage or workshop.
 Fan speed can not be adjusted.

Unit Configurations:
Electric space heaters are available in hard wired permanently installed or plug-in portable configurations. A permanently installed heater mounts out of the way on a wall or ceiling, while a portable heater is plugged in (special receptacle is usually required) where heat is needed and placed on a hard, level surface.

Portable Electric Space Heater:

Installation Overview:
1) Suspend the space heater using the mounting bracket or place on a hard surface. Maintain suggested clearances from walls, ceilings, and combustible materials.
2) Wire power to the heater or plug it in (special power receptacle is usually required).

Commonly Asked Questions:

1) How efficient is an electric garage heater?
ANSWER: Electric heat is 100% efficient because all the electricity used is converted to heat. However, the fossil fuel power plants that generate most electricity are typically only 30 to 40 percent efficient. Thus even with a 100% efficient electric heater, the amount of fuel needed for a given amount of heat is much more than if the fuel was burned in a furnace or boiler at the building being heated instead of being turned into electricity and then turned into heat.

2) How do I calculate the heating load for my garage or workshop?
ANSWER: Call us or use our simple heat load calculator. Do NOT fall for equipment that is advertised as “will heat up to 400 square feet”. Heating a 400 square foot insulated garage in Florida is a lot different then heating a 400 square foot uninsulated metal garage in Maine. We are happy to run a detailed engineering calculation that will help you pick the perfect heater for your space.

3) How do I control an electric space heater?
ANSWER: A thermostat cycles the heater to maintain the desired temperature. Most electric space heaters have built-in thermostats. If not, you’ll need to install a wall or unit mounted thermostat to tell the heater when to run.

4) What is the best location in my garage or workshop to install my electric unit heater?
ANSWER: The electric heater in your garage or workshop should be located in the coldest area, and it should be angled slightly so it blankets warm air across the coldest wall.

5) What clearances must be maintained?
ANSWER: Requirements vary depending on the heater, call us or check your heater’s installation instructions.

6) What is the best location to install a thermostat in my garage or workshop?
ANSWER: A well insulated interior wall is the best place for the thermostat.
If it is located in a cold spot, it will run the heater more then it should. If it is located in an area that receives warm direct sunlight, it will run the heater less then it should.

7) What kind of sound can I expect from an electric heater?
ANSWER: While sound is created anytime fans and motors are used to move air, unit heaters are designed to minimize their sound level through the careful selection of motors, fan blades and the design of the air intake opening. Sound is comparable to a box window fan.

HVAC Coil manufacturers can over emphasize the need to designate left or right hand. The different reference points used can be intimidating and confusing. Often times, it just doesn’t matter.

Do you need to specify a left or right handed steam HVAC coil?
Not generally. Most steam HVAC coils are universal. Steam coils are normally 1 or 2 rows deep. This allows you to reverse the piping connections. The supply connection must be on top and the return connection must be on the bottom. Return connections on steam coils need to be as low as possible for proper condensation removal. As long as you have the return connection lower than the supply connection, it does not matter if you have a right handed or left handed steam HVAC coil.

Do hot water HVAC coils need to be left or right handed?
Hot water and steam coils are almost identical since both are typically only 1 or 2 rows deep. The major difference is the supply and return feed. If possible, feed the bottom connection and return the top connection. This helps promote the removal of air that can get trapped in the HVAC coil.

Which HVAC coils require a ‘hand’ designation?
Cooling coils that are larger than 2 rows require a hand designation. All coils except steam coils should be installed in a counter-flow arrangement. This is particularly true for HVAC coils with three rows or more. Counter-flow refers to the direction of the air across the fins relative to the fluid in the tubes. A counter-flow arrangement will produce the most capacity. Using a chilled water cooling coil as an example, the coldest water entering the coil should be cooling the coldest air leaving the coil. See below for a more detailed explanation of counter-flow.

A detailed explanation of counter-flow:
A HVAC coil is an air to fluid heat exchanger. Air is traveling on the outside of the tubes and fluid is traveling on the inside of the tubes. The most important principle in designing any heat exchanger is put the air and the fluid in a counter-flow arrangement. This means that the air and water travel in opposite directions through the heat exchanger. You always want the water, refrigerant or steam entering on the side of the exchanger where the air is leaving. This means that as the air goes from left to right, the fluid is traveling from right to left. All coils are tested in counter-flow arrangements and it provides maximum efficiency. You can lose 15% of the capacity when a HVAC coil is piped backwards. This is the primary reason why deeper HVAC coils are designated as right or left hand. Counter-flow has negligible effect on 1-2 row coils.

How to reference left or right hand?
When you stand in front of a coil, the connections will either be on the right or the left side. This is what they mean by “hand” connections. Most manufacturers determine left and right while facing the entering airside of the HVAC coil. A few manufacturers determine left and right while facing the entering airside of the coil (the air hitting you in the face)

When facing the end of the coil with the pipe stubs, the supply connection should always be at the bottom, leaving air side of the coil. The return connections should always be at the top entering air side of the coil.

Is there a proper hand for replacement coils?
When you are replacing a chilled water coil the connections are almost always on the bottom right and top left. Once you determine the supply and return feeds, hand designation is not important. The HVAC coil is either bottom right / top left or bottom left / top right. The most important factor with replacements is to match what was there, unless you realize the original coil was not piped in a counter-flow arrangement. This is a great situation, you can share your expertise with your customer and show them how to save money!

In summary, hand designation isn’t a difficult concept, but many HVAC coil manufacturers make it seem more difficult than it needs to be.

This article was provided by H-Mac Systems, Inc. H-Mac Systems, Inc. is the place to purchase residential, commercial and industrial heating, ventilating, and air conditioning equipment (HVAC Products) for your home, garage, workshop, or industrial facility. Visit them online at store.h-mac.com.

1. If you eliminated the fins and only used the tubes, you would only get about 30% of the performance compared to the same HVAC coils with fins. The fins impact heat transfer much more than the tubes.

2. Because steam is erosive, steam coils are often constructed differently then hot water coils. Water and steam coils cannot always be used interchangeably. Some duct booster coils can be used with hot water or steam. Be aware that the steam should NOT be modulated through this type of coil if it will be exposed to below freezing air temperatures. As the valve modulates down, there is not enough pressure to push the condensate through this type of coil. If you are using steam in a hot water booster coil, you should choose 2 position control (on/off). Modulating type steam coils, aka “non-freeze” steam coils should not be used with hot water.

3. The industry has arbitrarily named 1 and 2 row coils “hot water HVAC coils” and 3 – 10 row coils “chilled water HVAC coils”. Hot water coils and chilled water coils are constructed the same. Hot water temperatures are much higher than the air temperature, resulting in a coil with fewer rows. Chilled water temperatures are very close to the air temperature, resulting in a much deeper coil.

4. Chilled water and DX (direct expansion) HVAC coils are identical except for the supply and return arrangement. You can’t feed refrigerant through a M.P.T. (male pipe thread) connection and header arrangement. You have to replace the standard hydronic feed with a refrigerant distributer. The “spaghetti tubing” connected to the distributer feeds as many tubes as you want it to feed. Beyond that, chilled water and DX HVAC coils are identical.

5. Fins have corrugations that run the entire height and depth of each fin. Fins are not flat. Corrugations promote turbulence, increasing the surface area and coil efficiency. Corrugations also help in preventing moisture carryover which is very common with chilled water HVAC coils running at face velocities higher the 550 FPM.

6. When you look at HVAC coils, you can see that the fins are rippled. This is another way to mix up the air, causing more turbulence which creates more heat transfer, increasing coil efficiency.

7. Most HVAC coils last 15-20 years. HVAC coils can last as long as 30 years if they are properly maintained. Proper maintenance includes regular cleaning on the airside, and proper treatment of the fluid passing through the tubes.

8. 5/8” tube chilled water coils use more tubes per row than ½” tube chilled water coils. The ½ tube coils have more finned surface area, but the thicker 5/8” tubes take up more surface area. The performance of the two different HVAC coils is similar. People often choose the 5/8” tube coil due to its slightly lower water pressure drop and thicker tube wall thickness.

9. Since you pay for copper by the pound, you will pay more for a 5/8” tube coil than a 1/2” tube coil. This is because the wall thickness on a 5/8” tube coil is 10 - 15% more than a comparable ½” tube coil. Even though the performance is the same, you will pay more for a 5/8” tube coil. One could claim that a 5/8” tube coil will outlast a ½” tube coil.

10. 95% of the overall cost of HVAC coils is the finned surface area, number of rows and fins per inch. Casing dimensions, coil depth, connection sizes and header sizes only account for 5% of the overall cost. Changing the materials can have a huge impact on the overall cost. Stainless steel casings and copper fins are very common in corrosive environments. The material costs are higher, and the heat transfer properties of different materials will affect the size of the coil. If you change the fins to copper, you will lose about 15% of the capacity, which means you will need a bigger coil.

Space cooling can be conveniently and economically accomplished using an electric evaporative cooler (sometimes called a swamp cooler or desert cooler). Compared to a compressorized air conditioner, an evaporative cooler is inexpensive to buy, inexpensive to run, easy to operate, low maintenance, and able to cool areas where other cooling solutions might be difficult to install, expensive, or impractical.

Operating Principle
An evaporative air conditioner lowers the temperature of air by evaporating water, similar to the way the human body cools itself by sweating. The heat from warm, dry air is absorbed by the evaporating water and the result is cooler air with a higher moisture content.

A fan in the evaporative cooler moves air to be conditioned through damp pads moistened with water that is continuously pumped onto the pads.

Warm, dry conditions are best for an evaporative air conditioner – humid air absorbs less water and heat, providing less cooling.

Benefits
• Low maintenance
• Very reliable, only moving parts are fan and pump
• Lightweight
• Fast, easy setup
• Uses less energy than compressorized air conditioner

Things to Consider
• High humidity decreases cooling capacity. For example, at 90 degrees F and 10% relative humidity, a certain model evaporative cooler will discharge air at 65 degrees F. At 90 degrees F and 50% relative humidity, this same cooler has a discharge air temperature of 78 degrees F.
• Leaving air is 80-90% relative humidity and may cause corrosion, condensation, or discomfort
• Water is required to wet the evaporative pads and is typically supplied by manually filling an internal tank or hooking up to an external water source for automatic continuous operation

Configurations
Most evaporative coolers are mounted on wheels to they can be easily moved. Smaller units have internal water tanks, and larger units have external tanks. Standard ¾” hose connections are common for all capacities and allow automatic water fill and continuous operation.

Installation Overview
1) Fill water tank or connect to external water source.
2) Plug it in.
3) Start up and fine tune direction of cooling airflow.

Commonly Asked Questions

1) What is the best application for evaporative cooling?
ANSWER: Evaporative cooling is especially well suited for climates where the air is hot and humidity is low. The western/mountain states are excellent locations. In dry climates, the installation and operating cost of an evaporative cooler is much lower than refrigeration-based air conditioning, often by 80%.
In moderate humidity locations there are also many cost-effective uses for evaporative cooling. For example, industrial plants, commercial kitchens, laundries, dry cleaners, greenhouses, spot cooling (loading docks, warehouses, factories, construction sites, athletic events, workshops, garages, and kennels) and confinement farming (poultry ranches, hog, and dairy) all often employ evaporative cooling.

2) What size cooler do I need?
ANSWER: This depends on the temperature and humidity of the air you’re cooling as well as the size of the space. Evaporative coolers have performance charts listing temperature drop at different air conditions as well as area coverage – use these charts to select your unit. Check out the H-Mac Systems evaporative coolers page at http://store.h-mac.com/swampcooler.html and don’t hesitate to e-mail or call with any questions.

Get more details and pricing on these evaporative coolers at:H-Mac Systems Online Store.

For people who live in fairly arid climates, swamp coolers (a.k.a. evaporative coolers) are an efficient way to stay cool – and are less expensive top purchase and operate than air conditioners.

Dry air absorbs moisture through evaporation. If water is continuously evaporated into dry air, heat is absorbed and the temperature of the air is lowered. Swamp coolers take hot dry air, cool it by evaporating water into it, and circulate the cool air throughout a home.

Unlike air conditioners, when using swamp coolers the moist air must be able to escape through open windows. Windows are kept closed when using air conditioners to keep cool air inside, but open windows are essential when using swamp coolers.

After taking a shower, when you are still wet and exit the bathroom, you feel chilly due to the evaporation of water from your body. While you were still in the bathroom, you felt warm and damp because water could not evaporate as rapidly when the surrounding air was humid.

All swamp coolers work in the same basic way. Water is pumped onto spongy pads, hot dry air is blown through the pads and then the cool air leaves the swamp coolers. Swamp coolers use less energy than air conditioners because there are no energy hungry compressors. The only moving parts are a fan and a pump.

Increasing Swamp Cooler Efficiency and Lowering Energy Requirements.

1. The first thing you need to do is install a swamp cooler. Swamp coolers come in all different shapes and sizes. Once you purchase a swamp cooler, make sure that you install it as per the manufacturer’s recommendations.
2. As previously mentioned, open a window. If the air indoors becomes too humid, the swamp cooler will not be able to evaporate water as rapidly and therefore will not be able too cool the area as efficiently.
3. The warmer the surrounding air, the more water can be evaporated. The greater the difference in temperature between the cool water and the hot air, the more efficient your swamp cooler will be. So, don’t try to cool your house just a degree or two. Wait until it is sufficiently hot (Usually mid-80s).
4. Keep your evaporative pads clean. If they become clogged, they will not work efficiently. Impurities in pads will prevent the maximum amount of water from being evaporated and decrease the efficiency of swamp cooler.
5. Do not run a swamp cooler and air conditioner at the same time. The two operate on almost opposite principles. This will prevent either from working efficiently. This is huge waste of energy and environmentally unfriendly.
6. Finally, keep water in your swamp cooler. If the cooling pads become dried out, there will be no water to evaporate and no cooling will take place.

Follow these easy steps and you will efficiently cool your home during those dry summer months. You will also be doing your part in helping the environment by conserving energy and not using CFCs to cool your home.

1. Insulate – Insulation reduces the amount of heat that enters your home from outside. In a well insulated house, less energy is consumed battling heat conducted in from the outside through walls and ceilings.

2. Seal up air leaks – A tightly sealed home reduces the amount of warm air that leaks into your home from outside. In a well sealed home, less energy is consumed battling warm air leaking in from outside.

3. Use shades to prevent the “greenhouse effect” – Don’t let your home heat up inside like a car with closed windows on a hot sunny day. Closing window shades during the day will prevent sunlight from entering your home and heating it up, decreasing the load on your cooling equipment.

4. Attic fan – Attics can reach temperatures of 160 degrees F during the summer. When this happens, heat from the attic leaks into the living spaces of your home and makes your cooling equipment work harder. An attic fan removes hot air from your attic and replaces it with cooler air from outside, bringing the attic temperature down to 15-20 degrees F above the outdoor temperature. Solar attic fans have recently been developed to provide attic ventilation while using no electricity at all.

5. Swamp cooler – A swamp cooler provides cooling by evaporating water into the air, just as your body cools itself by sweating. Swamp coolers use far less energy than traditional compressorized air conditioners. You’ll want to leave the windows open when using one of these - air should only pass through the cooler once, so be sure to bring in fresh air.

6. Ceiling fan – A ceiling fan cools in summer by circulating air. The air temperature is not reduced, but people feel cooler due to the breeze.

7. Turn air conditioner thermostats up a few degrees – Instead of cooling your home to 72 degrees F, try 75 or 78 degrees F. Every degree you increase the thermostat setting reduces the load on your cooling system.

8. Cool only the spaces you are in – Zone your cooling system or use window air conditioners or portable air conditioners so you air condition only the area you are in. This will greatly reduce energy consumption.

9. Programmable thermostats – Set a programmable thermostat up for your schedule do it runs air conditioning only when you are home.

10. Change or clean filters – Clean filters increase the airflow and efficiency of air conditioning equipment.

Ceiling fans are aesthetically pleasing, useful and energy efficient. While most people know that fans can provide a cool breeze in the summer, many don’t realize that a fan can also be used to force warm air down from the ceiling in the winter.

Light kits can even be added to increase the usefulness of many ceiling fans.
This how-to includes basic instructions for installing a ceiling fan. Remember, however, to always consult the manufacturer’s instructions during actual installation. Since ceiling fans are most often used to replace existing light fixtures, the wiring to the fan should already be complete. Installation is not difficult, and only requires that you pay attention to the instructions included with the fan. If additional wiring must be done to install your fan and you are not familiar with wiring, consult a professional electrician. All wiring must conform to local and national codes.

Things to Consider
• Ceiling fans are inexpensive to purchase and operate and can make a huge difference in your home’s climate during both summer and winter months.
• Replacing a central light fixture in almost any room with a ceiling fan + light kit can add beauty while increasing air flow.
• Because a fan uses almost the same amount of power as a ceiling fixture, the electrical circuit won’t be overloaded. If your fan includes lights, be sure the circuit it’s on has enough capacity to handle the additional load. If not, you must run a new circuit with a new circuit breaker from the house’s main service panel or sub-panel to the fan.
• If there is no central light fixture, you’ll have to create a place to hang the ceiling fan. Then, you’ll need to bring electrical power to it. You can tap into an existing circuit to do this.

Before Installation
1. Determine what size fan you need. If the dimensions of the room that you will be installing the fan in are no bigger than 12’ in any direction (length or width), then you should use a 36” fan. If the largest dimension of the room is between 12’ and 15’, then you should use a 42” fan. If the largest dimension of the room is greater than 15’, then you should use at least a 52” fan.

2. Before you begin installing your ceiling fan, make sure the power to the fixture is off. Double check this with a high-voltage neon tester if possible. Lock the breaker box to make sure no one accidently turns the power back on while you are installing the fan. Make sure you have any necessary permits, if applicable. Make sure that you have enough room for a fan.

3. Fans should be mounted no less than 7’ from the floor and 12” from the ceiling. 18” from the ceiling is preferable for more air flow. Fans must be mounted at least 24” from any obstructions. An appropriate junction or outlet box securely attached to the building structure is required. Replace the old box with one labeled as approved for ceiling fans or ceiling suspended “paddle” fan installation. The box and its support must be able to support the moving weight of the fan. Use the installation hardware recommended by the junction box manufacturer. Fans of over 35 pounds, with or without accessories, require additional support independent of the outlet box. Check with a professional about your local building codes.

Installation Steps
Step 1: Install the hanger pipe - Place the hanger pipe in the hole on the top of the fan motor. Slowly draw out the wires from the center. Tighten the set-screws provided with the fan.

Step 2: Attach the blades - Attach the fan blades to the main body. Standard fan blades come with a two-pronged attachment. Connect the screws through the holes present on the blades to the flanges. Tighten them using a screwdriver.

Step 3: Install the hanger bracket - Install the hanger bracket using lock washers and screws. Lock washers should be provided with the fan but if they are not a part of the installation kit then purchase them from a hardware store. Lock washers will prevent the screws from loosening when the fan vibrates.

Step 4: Wire the fan – Determine the hot and common wires by color: black is hot for the fan, blue is hot for the light kit, white is common for the fan and light kit, and green is ground. In all cases, make sure that all exposed wiring is secured inside wire nuts. Wires need to be connected in such a way that the black house wires are connected to the black fan wires while the white house wires are connected to the white fan wires. The standard colors for grounding wires are either bare copper or green. You should wire-nut the ground wires from the box to those from the power supply and the fan. Once wiring is complete, gently push wires into the electrical box.

Step 5: Turn on your new fan and check for proper operation.

Solar Attic Fan
Easily installed and free to operate, solar attic fans are a smart choice for homeowners who want to save money cooling their homes in summer, prevent ice dams in winter, and extend the lives of their roofs.

Solar Attic Fan Operating Principle
A solar attic fan uses photovoltaic panels to convert sunlight into electrical power. The electricity generated is used to turn the fan motor, exhausting air from the attic of a home.

Benefits
• In summer, temperatures in an unventilated attic can exceed 160 degrees F. A properly sized solar attic ventilation system will reduce attic temperature to 5-10 degrees F above the outdoor temperature. Ventilating the attic reduces the amount of heat transferred from the attic to the home, decreases the load on the air conditioning system (reducing your electric bill), and extends the life of the roof.
• In winter, heat trapped in the attic may melt snow on the roof, which trickles down and creates destructive ice dams in the colder eaves.
• The attic becomes warmest when the sun is the strongest. A solar attic fan runs the hardest when the sun is strongest.
• Everyday home activities such as cooking and showering create moisture which collects in the attic and promotes mold and mildew growth, reduces the effectiveness of insulation, and attacks the wooden attic structure. Year round fresh air circulation from a solar attic fan removes this moisture and prevents moisture related problems.
• Zero operating cost.
• Installation can be done by a handy homeowner. No electrician is required.
• Quiet operation.

Solar Attic Fan Detailed Image

Things to Consider
• The cost savings due to reduced air conditioner load depends on the price of electricity in your area, the amount of attic space in your home, the efficiency of your attic insulation, and the amount of ventilation your solar attic vent is able to provide. A typical installation will usually pay for itself in savings within 1-2 summers of use.
• A solar attic fan should not be used when air from the living areas of the home can freely enter the attic. This would result in conditioned air being removed from the home. Any openings between the attic and the home should be sealed before a solar attic fan is installed.
• Properly sized attic vents are required to allow fresh air to enter the attic and replace the hot air removed by the solar attic fan.
• Solar attic fans should be mounted away from ridge vents and gable vents.
Configurations

Solar attic fans are available three configurations:
1. Self flashing roof solar attic fan: The fan base is flat and designed to slide under shingles and attach directly to the roof.
2. Curb mounted solar attic fan: The fan base is a cap designed to fit over a curb which is attached to the roof.
3. Gable fan: The fan exhausts horizontally through the gable end of the attic.

In addition, solar attic fans are available with fan mounted or remote solar panels.

Installation Overview
1) Cut hole in roof (South side is recommended), taking care not to cut through any roof framing members.
2) Slide unit under shingles
3) Reshingle around fan as necessary.

Commonly Asked Questions

1) What size fan do I need?

ANSWER: A solar attic fan should be sized to provide 10 attic air volume changes per hour.
To figure out what flow rate this works out to, figure out the volume of your attic in cubic feet. Multiply your attic volume x 10 air changes per hour to get the total flow required per hour.
Since fans are sized in terms of their cfm (cubic feet/minute) output, divide your total flow per hour by 60 to get cubic feet per minute.
Required flow rate in cfm = (attic volume x 10) / 60
Now check the fan specifications to find the fan or combination of fans required to meet your ventilation needs.
It is also very important to make sure there is enough air inlet area in your attic to allow fresh air to enter and replace the hot air being exhausted. A minimum of 1 square foot for every 360 cfm of exhaust is required. Typically soffit vents are used as inlets.

2) How long will a solar attic fan last?

ANSWER: Solar attic fans are designed to provide many years of trouble free operation. The length of manufacturers’ warranties are a good indicator of the high standards these fans were designed to:
Attic Breeze Fans Lifetime parts warranty
Solar Star Fans 5 Year parts on solar panel and motor, 10 years on all other parts.
Natural Light Fans 25 Year parts warranty
SunRise Solar Fans 5 year parts warranty on motor, 10 years on all other

3) How is a solar attic fan controlled?

ANSWER: A thermal switch is often used to control a solar attic fan. This switch only allows the fan to run when the attic is warmer than 80-90 degrees F. Running the fan only when the attic is hot extends the life of the fan motor and results in less heat loss to the attic in winter, but does not allow the fan to reduce moisture build-up in the attic at all times and does not allow the fan to prevent ice dams during the winter.

In moderate humidity locations there are also many cost-effective uses for evaporative cooling. For example, industrial plants, commercial kitchens, laundries, dry cleaners, greenhouses, spot cooling (loading docks, warehouses, factories, construction sites, athletic events, workshops, garages, and kennels) and confinement farming (poultry ranches, hog, and dairy) all often employ evaporative cooling.

Looking to purchase? Follow this link for the best selection and prices anywhere:
Solar attic fans

How to Maintain a Window Air Conditioner
A window unit, commonly called a window air conditioner, is great for cooling a single room or a group of rooms that do not have partition walls.

A window air conditioner consists of a blower, fan, compressor, evaporator coil, condenser coil, thermostat and filter.
A common schematic is illustrated below.

A look inside a window air conditioner

Internal maintenance to the sealed refrigeration circuit (coils, compressor and motor) should be left to a trained technician. There are minor steps that you can take to keep your window air conditioner running strong.

During the winter months, window units should be removed and stored indoors in a clean, dry area. If you are storing your window air conditioner in the basement, be sure to elevate it to make sure it doesn’t get exposed to water. Always keep your unit in the upright position to prevent oil and refrigerant migration.

Warning: Before any work is done on your appliance, it should be unplugged and discharged. Failing to do so could result in severe, and potentially lethal, electrical shock.

Maintaining Basic Components
(THESE PROCEDURES SHOULD ONLY BE ATTEMPTED BY A TRAINED TECHNICIAN)
The filter, power cord, coils, switch, thermostat, drain ports and fan are important to service on a routine basis to avoid serious problems. Typical guidelines for maintaining these parts are as follows (BE SURE TO REFER TO YOUR OWNER’S GUIDE FOR SPECIFICS ON YOUR UNIT):

Filter
Before every cooling season and once a month during the cooling season, the filter should be removed, cleaned and replaced. If you live in a particularly arid climate, this may need to be done more frequently. Most window air conditioners have a washable filter that looks like a sponge.

Clean filters with a mild detergent and water, rinsing well. Let the filter dry completely before replacing. If your window air conditioner comes with a fiberglass furnace style filter, do not wash it; replace it with a new filter of the same type.

Power Cord
If your air conditioner stops working and you suspect that it is not getting power, there could be a problem with the power cord. Power cords may become worn and fail to supply electricity to the air conditioner. To check the cord, remove the control panel. Unscrew the cord terminals and then attach a test wire across the bare lead wires.

Hook the clips of a volt-ohm-millimeter (VOM) set to the RX1 scale to the prongs on the cord’s plug. If the meter reads zero, the cord is functioning. If the meter reads higher than zero, replace the cord.

Evaporator and Condenser Coils
Clean the evaporator and condenser coils the same time you clean the filter; before the start of the cooling season and once a month during the season. If your area is particularly dusty, this may need to be done more frequently. The coils can be cleaned with a vacuum cleaner hose. If the fins on the coils become bent, use a fin comb from your local hardware store to straighten them.

Switch
The selector switch, behind the control panel, turns the window air conditioner on and off. If the air conditioner does not run on any setting, and you have already made sure that the power cord is working, you may have a faulty switch. To check, remove the control panel and see if there is burnt insulation or black marks on the terminals. If so, replace your switch with one of the same type.

Thermostat
The thermostat is also located behind the control panel. If you believe you have a problem with your thermostat, here is how to test and replace it:

1) Remove the grille and control panel. There will be a temperature sensing bulb extending from the thermostat to the face of the evaporator coil
2) Carefully remove the thermostat, noting the position of the sensing bulb. It must be replaced in the exact spot.
3) Check the thermostat with the VOM setting on the RX1 scale. Clip the probes to the thermostat terminals and turn the temperature control to the coldest setting. Your meter should read zero if the thermostat is working properly. If the reading is greater than zero, replace the thermostat with a new one of the same type.

Drain Ports
The evaporator coil condenses water vapor from the air and funnels it through a drain port. At this point, the water is blown against the condenser coil, where it is dissipated.

Drain ports can become dirty and get clogged with debris. This results in water leakage, usually through the bottom of the front grille. To prevent clogging, clean the drain with a piece of wire. Do this at the beginning of every cooling season and when your unit starts to leak.

Fan
If your fan is not working or if it is particularly noisy, it is usually caused by loose or dirty fan blades. Follow these steps to repair the fan:

1) Locate the fan inside the cabinet.
2) Use a soft cloth and/or vacuum to clean out any debris.
3) Check tightness of all blades. Vibration can loosen fan fasteners. Use a screwdriver or Allen wrench to tighten screws that connect the fan hub to the motor shaft.
4) If your fan has oil ports, apply a few drops of 20-weight non-detergent motor oil.
5) If you suspect a faulty motor, test with the VOM on the RX1 scale. Connect VOM probes to disconnected terminal wires.

If the meter reads between 3 and 30 ohms, your motor is functioning properly. If your meter reads zero or it is extremely high, replace the motor.

To remove the fan motor, remove the fan blades, power wires and mounting bolts. Install a new motor by reversing this procedure. If the condenser coil prevents motor removal, do not attempt to remove the motor. Call a professional.

If any other problems occur with the motor, compressor or coils, a professional service person should be called.

By doing simple maintenance and repairs as described in this article, you can significantly extend the life and efficiency of your window air conditioner

keep looking »