Capitol Hill Heating Repair Question: What Are Flue Gas Spill Switches?

February 1st, 2012

While some components of a heating system make sense to the average homeowner in Capitol Hill – think blower fan, thermostat and air ducts – others are more esoteric and prone to bouts of head scratching.

So, you may find yourself asking “what the heck is a flue gas spill switch?”

As you know, gas heating appliances produce heat by means of combustion. The gas line feeds gas into the appliance, the gas is ignited, and the burning gas produces heat. It’s a simple concept that goes all the way back to our caveman ancestors building fires to keep warm, and it is the same process in gas furnaces, boilers and water heaters.

In addition to producing the cozy heat we love in the winter time, this combustion process also releases gases. Known collectively as “flue gases,” some of these – carbon monoxide being the most notorious – can be very toxic. This why we have flues or chimneys in our homes– to give these gases a means of egress.

A flue gas spill switch is designed to shut down the furnace if these gases start seeping out. It is made up of a sensor or series of sensors that detect heat outside the flue, not unlike the flame sensor in your furnace. If flue gases start to escape and pass by the sensor, the sensor heats up and signals the furnace to shut down. This cuts off the power and gas, so that no more flue gases can leak into the home and create a health concern.

If your furnace has been abruptly shutting down, it could be your flue gas spill switch trying to tell you that you have a leaky or cracked flue. If this is the case, you want to have it repaired right away. The constant off and on is not good for the furnace, and more importantly, those flue gases can be exceptionally hazardous to your family’s health.

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Washington DC HVAC Question: How Much Ventilation Do I Need for My House?

January 25th, 2012

By now you’ve probably heard how important it is to have good ventilation in your Washington DC home. Especially if your home was built in the 1980s or early 1990s when ventilation issues were prevalent, you may not have enough clean air moving through your home. But, how much ventilation do you need? What is enough and if you don’t have it, how do you ensure your home is retrofitted properly?

How Much Ventilation?

Most recommendations for ventilation come from the Home Ventilation Institute, which provides a series of standards of measurement for builders and contractors retrofitting homes for better ventilation. Here are some of their recommendations and how they might apply for your home:

  • Bathroom – Small bathrooms (less than 100 sq. ft) need 1 CFM per square foot of bathroom. The number goes up for each fixture if you have a large bathroom.
  • Kitchens – Your kitchen range needs at least 100 CFM if against the wall and upwards of 150 CFM if on an island.
  • Ventilators – If you have an HRV for your home, you should have at least 100 CFM for 2,000 square feet and another 50 for every 1,000 square feet of home size being ventilated.
  • Home Ventilators – The actual volume of CFM for ventilators depends on the type of ventilator being used. For example, a whole house ventilator needs upwards of 6,000 CFM for a 2,000 square foot home. Attic ventilators need 1,400 or more.

So, what does this mean for your Washington DC home? It means in general that you need a lot of ventilation and that the best way to get it is through mechanical ventilation techniques combined with your air handler and ductwork.

Especially if you recently added insulation and weather proofing to your home but have not yet updated your ventilation, you might have a major air quality problem, so have a professional measure your home’s air flow as soon as possible.

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Washington DC Heating Guide: Basic Boiler Maintenance

January 18th, 2012

The boiler in your Washington DC home is a sensitive piece of equipment that needs routine maintenance and repairs. Regularly maintaining your boiler is especially important for safety reasons. Many boiler malfunctions and accidents are due to neglecting some of these basic tasks.

Even if you’ve just installed a new boiler, the safety valves and settings should be checked by a professional on a regular basis to prevent a breakdown or hazard. We recommend that you schedule a boiler inspection and cleaning at least once a year. Call Polar Bear if you have any questions about boiler maintenance.

A service technician will measure the pressure, drain and remove sediment buildup, test the efficiency ratings, and make sure your boiler is set at the right temperatures. Regular maintenance can also help you determine whether or not you need a boiler replacement. By keeping track of performance levels, you will be able to tell when it’s time for an upgrade.

Other tasks performed during an annual maintenance visit include cleaning and lubricating all the components, checking for any leaks or clogs, and testing gas boilers for any carbon monoxide intrusion. If you have any gas appliances in your home, you should always have carbon monoxide detectors and test them once a month.

Boiler pressure is something that you can check often on your own. If you aren’t sure how to read the pressure gauge, or if you aren’t sure what the right pressure should be, just call one of our technicians to walk you through this process.

Always call Polar Bear if you have any problems with the boiler in your Washington DC home. We are here to help and answer any questions you may have.

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Happy Martin Luther King Day from Your Washington DC Area HVAC Contractor!

January 16th, 2012

Happy Martin Luther King Day! This holiday is not just about celebrating civil rights but also about serving your community. If you have the day off today, why not try spending it helping others? From volunteering at an animal shelter to helping the homeless, there are hundreds of ways you can make your community a better place to live. Have a great holiday!

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Washington DC Heat Pump Guide: Understanding the Defrost Cycle

January 11th, 2012

If your Washington DC home has a heat pump, you’ll want to understand the defrost cycle to help you maintain your heat pump and troubleshoot repairs. While this is a basic guide, you should call a qualified HVAC technician if you experience major issues with your heat pump.

During the winter when a heat pump is heating your home, the cooler outdoor air that’s pumped in and heated may have excess moisture. The outdoor coil evaporates this moisture, but under certain weather conditions, frost can accumulate on the coil and decrease the overall efficiency of the heat pump.  To help reduce the potential for damage from the frost, heat pumps are manufactured with a defrost cycle to melt the frost from the outdoor coil. The defrost cycle occurs often during heavy frost conditions, so check weather reports if your defrost cycle seems to be running often.

At the beginning of the defrost cycle, the heat pump switches to the cooling mode and temporarily warms up the outdoor coil until it reaches somewhere around 60° F to melt the frost from the coil. To increase the temperature of the coil, the outdoor fan is prevented from turning on until the outdoor coil reaches the desired temperature. Weather conditions and the timing device both affect the amount of time it takes for the heat pump to move through the entire defrost cycle.

In older homes, electric heating elements are sometimes installed to prevent cool air from being distributed throughout the home. This element will turn on with the defrost cycle and shut down the blower fan inside the house. If you have an older heat pump, you may want to consider upgrading to a more efficient model.

Call Polar Bear any time if you have questions about the defrost cycle for the heat pump in your Washington DC home.

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Pros and Cons of Various Heating Systems in Washington DC

January 4th, 2012

When it comes time to install a new heating system in your Washington DC home, there are a lot of options to consider. Many people get overwhelmed when confronted with all of the furnaces, boilers and heat pumps on the market these days. So, to help you get a handle on what each has to offer and which will offer you the best benefits, here is an overview of the modern heating system market.

Furnaces

Furnaces are the core of a forced air heating system and use gas, oil or electricity to heat air which is then circulated through your home by a blower in your air handler. Furnaces are among the most fuel efficient heating systems on the market today with options available at up to 95% AFUE (meaning it uses up to 95% of the fuel consumed to produce heat). They are also inexpensive to install and while they don’t last quite as long as boilers, they are highly efficient when well cared for.

Boilers

Boilers use gas, oil or electricity to heat water or steam which is then circulated through your home into radiators or baseboard heaters. The heated water or steam releases heat into your home and heats it in turn. While not quite as energy efficient as a high efficiency furnace, boiler heat is perfect for homes with existing radiators and no room for vents and ductwork. It also has less of an impact on indoor air quality since there is no air movement and boilers tend to last a very long time when well maintained.

Heat Pumps

Heat pumps are becoming increasingly popular, especially in milder climates where it rarely gets below 40 degrees F. A heat pump uses the same technology as an air conditioner to extract heat from outside using a compressor, evaporator coils, and condenser coils with refrigerant.

It is most efficient in the spring and fall when temperatures are mild, but it uses much less energy than either a boiler or furnace and it can be used in the summer to cool your home. When properly maintained, a heat pump will last 10-20 years and save quite a bit of money, though it is recommended that you have an emergency heat source for days when the temperature outside gets below 40 degrees F.

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Happy New Year’s Eve from Your Washington DC Heating and Air Conditioning Contractor!

December 31st, 2011

Happy New Years! We hope you have a great time tonight welcoming in the New Year and saying goodbye to the old. Forty-five percent of people make New Year’s resolutions; ours is to serve our customers even better than we did last year! If one of your resolutions is to make your home more green, remember that improving your insulation, sealing up any air leaks, and upgrading your HVAC system can have a big impact on your energy usage. A makeover for your house is great way to start off the year; it will make your home more comfortable and more environmentally friendly!

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A Question from Washington DC: What is a Gas Furnace Draft Hood?

December 28th, 2011

As every Washington DC heating and air conditioning contractor knows, a draft hood is a necessary part of any gas burning appliance. For a gas furnace in particular it ensures steady air flow to the burners to avoid flares or the pilot light being put out by fluctuation in temperature and air flow.

What the Draft Hood Does

The draft will change in the chimney as exhaust vents towards it – especially when going from cold air to hot. A draft hood is placed above the upper most part of the gas furnace to draw air into the chimney and makes it possible to draw more or less air through the chimney as necessary to create a constant flow.

This makes it possible for the burner to enjoy consistent air flow without any wind gusts or sudden temperature spikes or drops. Hot air, if not put through a draft hood would create a strong air flow through the burners.

A draft hood cools the air as it is released by the burners from 500 degrees F to between 300 degrees F and 350 degrees F. The cooling needs to be carefully calibrated to avoid condensation build up in the chimney however – a problem that occurs when the temperature gets too low.

Maintaining Pressure

The draft hood is a part of a larger system designed to maintain air flow to the chimney. For every cubic foot of gas burned, the furnace needs to have 15 cubic feet of air for combustion and another 15 cubic feet of air for dilution. A draft hood and the rest of the ventilation system make it possible to put a furnace that has many thousands of BTUs in the basement of your home and still supply it with enough air to burn gas and dilute the exhaust before it enters the chimney.

For all of these reasons, if you see your pilot light flickering irregularly, notice a backflow of exhaust or a burning smell in your furnace room, it’s important to call a Washington DC professional who can inspect and repair the problem before it becomes any worse. Not only can gas burner exhaust contain high levels of carbon monoxide, it can be bad for the device and the chimney if it doesn’t vent properly.

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Happy Holidays from Your Washington DC Heating and Air Conditioning Contractor!

December 21st, 2011

Everyone at Polar Bear Air Conditioning wishes you a very Happy Holiday! We hope you enjoy this time with friends, family and loved ones. Stay safe and warm this season! Also remember that whether you have a furnace, a heat pump, or a boiler, heating maintenance will keep your system running safely and at peak efficiency. If you haven’t had your annual checkup yet, we recommend you do so soon!

The holidays are a time to celebrate, and one of the best things about them is the great food. Here is a little treat we found that will make any day even better:

Gingersnap Cookies

“This melt-in-your-mouth ginger cookie recipe that I received from my grandmother has been enjoyed in my family since 1899.”

INGREDIENTS:

2 cups sifted all-purpose flour

1 tablespoon ground ginger

2 teaspoons baking soda

1 teaspoon ground cinnamon

1/2 teaspoon salt

3/4 cup shortening

1 cup white sugar

1 egg

1/4 cup dark molasses

1/3 cup cinnamon sugar

DIRECTIONS:

  1. Preheat oven to 350 degrees F (175 degrees C).
  2. Sift the flour, ginger, baking soda, cinnamon, and salt into a mixing bowl. Stir the mixture to blend evenly, and sift a second time into another bowl.
  3. Place the shortening into a mixing bowl and beat until creamy. Gradually beat in the white sugar. Beat in the egg, and dark molasses. Sift 1/3 of the flour mixture into the shortening mixture; stir to thoroughly blend. Sift in the remaining flour mixture, and mix together until a soft dough forms. Pinch off small amounts of dough and roll into 1 inch diameter balls between your hands. Roll each ball in cinnamon sugar, and place 2 inches apart on an ungreased baking sheet.
  4. Bake in preheated oven until the tops are rounded and slightly cracked, about 10 minutes. Cool cookies on a wire rack. Store in an air tight container.

For more details, visit allrecipes.com.

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Washington DC Heating Guide: Why Does Your Furnace’s Pilot Light Keep Going Off?

December 14th, 2011

If you have an older furnace with a gas pilot light and it keeps going out, heating your Washington DC home can become a frustrating process. Not only are you forced to trudge downstairs to light it every time you need heat, but you’re probably starting to worry that there is something wrong – either with your furnace or with your gas supply. Here are some possible reasons for your pilot light shutting off and what you can do about them.

  • Thermocouple – The thermocouple is used to generate electricity from the gas being burned by the pilot light to power the sensor that keeps the pilot light running. So, if the thermocouple goes bad or gets blocked in some way, the sensor won’t work properly and your pilot light won’t remain lit. Even a small problem with the thermocouple can lead to the valve closing and the pilot light going out.
  • Gas Pressure – If the gas pressure going to your furnace is too low, due to a leak, pipe problem or another appliance, the pilot light may not have enough gas to stay lit. While it is possible that the problem is not related to gas pressure, anything that affects the flow of gas into your home should be inspected by a professional. If you smell gas, leave the house and call your gas company immediately.
  • Mercury Sensor – The sensor in your pilot light that maintains the flow of gas to keep it lit can go bad. Keep in mind that these sensors almost always used to contain mercury (and often still do), so you should be careful with them. It’s best to call a professional who can replace and dispose of it properly.
  • Dirty Burners – Excess dust, lint, rust or sulfur build up can result in blockage of the burner holes. When this happens, gas will flood into the chamber but not light right away. When it does finally light, it will create a small boom or banging sound that will often put out the pilot light. Not only is this inconvenient, it is very dangerous. Fortunately, it can be avoided with annual cleanings of your furnace.

The best way to keep your pilot light lit at all times is to have someone inspect it once a year. If something happens in between, you can usually rule out cleanliness issues and call in a heating contractor to check the thermocouple and sensor.

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