Archive for April, 2011

How Does Central AC Work?

Friday, April 29th, 2011

We pretty much just take the fact of central air conditioning for granted these days. It is present almost everywhere and it is hard to imagine getting through a long hot summer without it. But if you are like most people, you probably do not actually know how central air conditioning works. While you can certainly take advantage of it without understanding it, the basic concept is pretty simple.

Basically, central air conditioning systems are composed of an outdoor unit that typically houses the compressor and condenser and an indoor unit that manages the flow of air throughout your house or other building. This indoor unit is typically either an air handler or a furnace, and it directs the flow of air through a series of ducts that feed into the various rooms of the house.

The cool air originates in the outdoor unit and is blown into the house, gradually absorbing heat as it goes, and that air is then returned to the outdoor unit to be re-cooled. What actually happens in the outdoor unit involves the cycle of a type of refrigerant from a gas to a liquid and back. In the condenser area of the outdoor unit, the pressure on the refrigerant is lessened and it is able to absorb heat from the air returning from the house.

This gas, while warmer than the liquid refrigerant, is still quite cold and acts to cool the air being passed back into the house. As that refrigerant moves along to the compressor area, the gas is converted to a liquid and is forced to release the heat it had been holding. In that way, the air conditioner is able to remove heat from the inside of your house and release it outside.

Your air conditioning system is also generally hooked up to a thermostat, which is what controls when the unit switches on and off. You can set the thermostat at the temperature you would like to maintain inside your house and the thermostat will signal the air conditioner to switch on when the indoor temperature rises above that level. And once the indoor temperature is again below the preset level on the thermostat, the air conditioner will switch off again.

What Is New in Air Conditioning?

Wednesday, April 27th, 2011

There are developments being made in air conditioning just about every day. This is a huge business, and so manufacturers are constantly trying to outdo each other as it is their only way to compete for customers. What this means for you as a consumer is that you will always have an excellent selection of products from which to choose.

Energy efficiency is one of the main selling points for any air conditioning system. For that reason, manufacturers are constantly working to come up with new and better models. The most advanced air conditioning systems on the market have energy efficiency ratings that by far surpass what was available even ten years ago and it is only going to keep getting better.

Another type of air conditioning system that is relatively new but is rapidly gaining in popularity is the ductless mini-split system. These and other compact air conditioners are popular because they can be installed virtually anywhere and do not take up much space. They also do not require the duct system that many other central air conditioners do.

In this way, ductless mini-splits combine the best of central air conditioning and more conventional window or wall mounted units. They keep individual rooms of your house cool and comfortable and can be controlled independently of one another, but they are also very quiet and energy efficient. In fact, ductless mini-splits are among some of the most energy efficient options available in the air conditioning world today.

For many years, enjoying the comfort that air conditioning provides has meant putting up with the noise of the compressor as well. Now, however, you can get the best of both worlds. Many air conditioning companies, in response to customer requests, have been working to curtail the noise and vibrations that air conditioners make.

This has affected models all up and down the line. Whether it is a window mounted unit you are after or a large central air conditioning system, you can rest assured that the model you buy today will be much quieter and produce a great deal fewer vibrations than your old system.

This is not only good news for you. It can also help to make your relationship with your neighbors a bit friendlier. The outside component of most air conditioning systems is usually where all the noise and vibrations come from anyway, and so your neighbors are likely to hear and feel it as well.

Different Types of Room Air Conditioners

Monday, April 25th, 2011

If you are like most people, you probably picture the air conditioner hanging out of the window when you think of room air conditioners. However, while these are by far the most popular type of room air conditioners, they are not the only option. When you are shopping for a room air conditioner, it is a good idea to explore all of your options before you make a purchase.

The traditional window mounted air conditioners have plenty of advantages, and that has helped to keep them at the top of the room air conditioner market for a long time. These types of units can be installed in windows of multiple sizes and you can just about always get them in yourself. These units are available in a wide variety of sizes too, so you will be able to match the unit to the size of the space you need to cool.

No matter what type of air conditioner you get, it is very important to make sure it is the right size for the task you have laid out for it. Bigger is not always better and you do not want an air conditioner that is too powerful for the space any more than you want one that is too small. Also, be sure to check the energy efficiency rating of the air conditioner you are considering before making your purchase. That can save you a lot of money over time as well.

Another type of room air conditioner to take a look at is a wall mounted unit. Many of the window mounted units can actually be used in this way as well, but the installation involves actually making a hole in the outer wall of your home so you will most likely need some professional help to get it in place.

Just like window mounted units, wall mounted air conditioners come in all sizes and with all different energy efficiency ratings. Always take care to check out the specifics of the model before you buy it to make sure it is the right choice for your home.

Portable air conditioners are a third option in the room air conditioner category. They typically have wheels so that they can be easily moved from one room to another and they have an exhaust hose that must be hooked up to a window to ensure adequate ventilation. These types of room air conditioners are usually more expensive than wall or window mounted units, but it is definitely convenient to be able to move them from one place to another.

Why Install a Ductless Air Conditioner?

Friday, April 22nd, 2011

As you explore your options in terms of a new home air conditioning system, you will probably have to decide whether you want a system that uses ducts to get the cooled air around the house or one that is considered ductless. Each type of air conditioning system is appropriate in certain situations, so it is important to understand the benefits of each before you can make a decision.

Duct air conditioning systems are the more traditional type on the market today. They generally consist of an outdoor compressor and condenser unit and an indoor air handler. The outdoor unit passes the cooled air through ducts to the air handler, which then takes over circulating the air through the house and back out to the condenser again.

It makes sense to install this type of air conditioning system if you have a large house or if you have ducts already in place. Duct air conditioners can cool a moderate to large sized house quite effectively and they can also be coupled with zone control systems to give you multiple climate zones within your house.

Ductless air conditioners, as their name suggests, do not rely on a system of air ducts to get cooled air distributed throughout your house. Instead, these types of systems use refrigerant lines to transfer coolant from the outdoor compressor to the indoor, wall mounted units. Each of these indoor units can take care of cooling one or two rooms, but in order to cool an entire house with one of these systems, you will need to install multiple indoor units.

However, these multiple indoor units can all be connected to the same outdoor compressor, and they can also be controlled independently. That gives you much greater control over which parts of your house are cooled and how much energy you are using to cool areas that may or may not be occupied.

Ductless air conditioners are generally more energy efficient than ducted ones, but their real advantage comes from the facts that they can be installed even in places where air ducts do not exist or cannot go. If you do not already have ductwork in your house, installing a duct system will add considerably to the price of installing a ducted air conditioning system. In a case like this, a ductless system is much easier and cheaper to install and certainly makes more sense.

Sealing Your Home Can Bring Big Rewards

Wednesday, April 20th, 2011

You use a lot of energy – and money! – keeping your house at a comfortable temperature. But if there are holes in the “envelope” or “shell” of your home, air from the outside can get into your home and drive up your energy costs.

Sealing the envelope of your home is one of the most cost-effective ways to improve energy efficiency and comfort. Energy Star estimates that appropriate sealing can save up to 20% on heating and cooling costs.

There are three ways to seal the envelope of your home:

  • Sealing air leaks to stop drafts
  • Adding insulation
  • Installing Energy Star windows when replacing windows

Sealing leaks. It may be easy to find some of the leaks in your home, because you can feel and sometimes even see them (for example, around windows and doors). You can seal these leaks with caulk, foam, and weather stripping.

Other leaks may be hidden in attics, basements, and crawl spaces. Common leak spots include:

  • Recessed lights
  • Outdoor faucets
  • Dryer vents
  • Attic hatches
  • Around light switches and cable, phone, or power outlets
  • Chimneys and furnace flues
  • The tops of walls that lead up to attic space

To find and seal these hidden leaks, it may be advisable to hire a contractor who can use special diagnostic tools. The expense is often quickly paid back in increased comfort and reduced utility bills.

Adding insulation. There are several common types of insulation — fiberglass (in both batt and blown forms), cellulose, rigid foam board, and spray foam. Different types are appropriate for different places in your home.

The strength of insulation is measured by “R-value” – its ability to resist heat flow. The higher the R-value, the more insulating power. Different R-values are recommended for different parts of your house, depending upon where you live.

Insulating your attic may offer significant savings, and can be a good DIY project if you are handy. To see if your attic can benefit from more insulation, look across your uncovered attic floor. If your insulation is level with or below the attic floor joints, more would probably be helpful.

Remember, however, that even well-insulated attics need appropriate ventilation to prevent mold growth in the summer and ice buildup in the winter.

Installing Energy Star windows and doors. Replacing windows and doors is a big project and may not generate enough energy savings to justify the cost. However, if you are remodeling or building a new home, be sure to choose Energy Star windows and doors. Energy Star windows and doors will not only help seal and insulate your home – they will also act as a sunscreen to protect your pictures, furniture, and carpets.

After Sealing Your Home: Check Air Quality!

After any sealing or insulating project it’s very important to have a professional perform a Combustion Safety Test on your gas and oil burning appliances to ensure that they are still operating safely.

It’s rare that homeowners seal their homes too tightly – especially if it’s an older house. However, if you are concerned, you can hire a contractor to test your home’s ventilation. If your home is too tightly sealed, he or she may recommend that you install a fresh air ventilation system.

Net-Zero Homes: An Exciting New Green Trend

Monday, April 18th, 2011

A net-zero home produces renewable energy equal to or greater than the energy the home consumes from public utilities.

Net-zero homes are part of the broader category of “green homes”(though non net-zero homes may still be considered “green” if they incorporate recycled building materials or other green technologies).

Net-zero homes are not the same as “carbon neutral” homes. Carbon neutrality can be attained for any home by purchasing carbon credits (often from geographically distant renewable energy sources) to offset the carbon emissions the home produces. Net-zero homes actually generate renewable energy on-site.

In regions of the world where homes must be heated or cooled for parts of the year, the design of a net-zero home is crucial. Net-zero homes minimize energy consumption by:

  • · Taking advantage of natural elements such as sunlight, prevailing breezes, topography (for earth-sheltered building and geothermal systems), and vegetation.
  • · Incorporating appropriate weatherization, insulation, and ventilation
  • · Using “daylighting” such as skylights and solar tubes, high-efficiency light fixtures and bulbs, high-efficiency appliances
  • · Reducing “phantom loads” of electrical power caused by electrical equipment on standby
  • · Reclaiming and reusing energy whenever possible instead of venting it outside as in conventional homes; for example, in some net-zero homes refrigerator exhaust is used to heat water.

Net-zero homes also produce their own renewable power using solar, wind, hydro, and/or geothermal “microgeneration” systems. The type of power generated will depend on climate and topography. Some net-zero homes are autonomous or “energy-autarkic” (i.e. “off-the-grid”) while others are connected to the grid and feed power back to the grid when it is not being used in the home.

While true net-zero homes generally must be specifically designed as such, it is possible to move toward net-zero energy usage for a conventional or existing home.

  • · Make the “envelope” of your home as efficient as possible with appropriate insulation, weatherization, energy-efficient windows, passive solar, and ventilation.
  • · Reduce energy demand by upgrading to high-efficiency furnaces (or heat pumps), air conditioning, lighting, and plumbing. Also, reduce “ghost load” from appliances on standby.
  • · Add micro-generation capacity. For most North American homes, solar is the most appropriate choice, though residential wind turbines are also gaining in popularity. Some local utilities even offer assistance and rebates for installing solar.
  • · If you are building a home, keep it as small as you can while still meeting your space needs.

And, the most important part of making your home as close to net-zero as possible: be disciplined about your daily energy use habits!

The Energy Star Label

Friday, April 15th, 2011

The Energy Star program is a joint program of the US environmental protection agency and the US department of Energy. The program’s goal is to help consumers save money and protect the environment through energy-efficient products and practices.

The best-known aspect of the Energy Star program is the Energy Star label, which is awarded to appliances and other items that are significantly more efficient than average. Energy Star efficiency guidelines vary depending on product category, but in general, Energy Star products use 20%-30% less energy than minimum federal standards.

The Energy Star guidelines were designed both with energy efficiency and performance in mind. While low energy use is one of the most important criteria for selecting Energy Star appliances, product performance, features, warranty, safety, and durability are also taken into account. Price is also a factor: if a product costs significantly more than other products in its category, it will only receive the Energy Star label if the up-front cost will be recovered through savings in operating costs within a reasonable amount of time.

The first Energy Star labels were given to computers and monitors in 1992. Now labels can be found on many other products, including:

  • Furnaces
  • Hot water heaters
  • Air conditioners
  • Dishwashers
  • Refrigerators
  • Light bulbs (florescent and LED)
  • TVs

Energy Star products can be found wherever appliances and electronics are sold. Look for the blue and white Energy Star label. You can also look for the yellow EnergyGuide label that is affixed to most heating and cooling systems and household appliances. This label is created by the Department of Energy and shows a product’s annual cost of operation compared to similar models. It will often indicate whether a product is Energy Star.

It’s important to note that while an Energy Star label indicates that a heater, air conditioner, or household appliance is more efficient than the minimum guidelines, it does not always mean that you are getting the most energy efficient option on the market. If you are making a major appliance purchase, use the Energy Star label to be sure every model on your “short list” is energy efficient. Then, look carefully at the EnergyGuide label to compare the efficiency of the models you are considering.

The EPA has also extended the Energy Star label to cover new homes and commercial and industrial buildings. To qualify for the Energy Star rating, a new home must use at least 15% less energy than standard homes (built to the 2004 International Residential Code). Energy Star homes usually include insulation, high-performance windows, energy-efficient heating and cooling systems, appliances, lighting, and water heaters.

The Energy Star standards and label have been recognized in many other countries, including Canada, Australia, Japan, New Zealand, Taiwan and the European Union.

Furnace vs. Heat Pump

Wednesday, April 13th, 2011

If you’re preparing to replace your existing heating system, you may very well be struggling with the question of whether to go with a furnace or a heat pump for all of your future home heating needs. Each of these systems have their own advantages and drawbacks, and once you’ve narrowed it down to one type or the other, you’ll still have a pretty wide variety of products to choose from.

Furnaces are still the most popular type of home heating equipment on the market. You can get furnaces that run on gas, oil or electricity, although gas furnaces are by far the most common type of furnace around these days. The latest models are extremely energy efficient, with AFUE ratings reaching into the high 90%s.

Like heat pumps, furnaces use ducts to transfer heated air throughout your home. They typically require regular maintenance once every year or two depending on the type of furnace you have, and they can be expected to last anywhere from 15 to 25 years when properly maintained. Most modern furnaces are also made to be compatible with a central air conditioning or cooling system as well.

Heat pumps, on the other hand, don’t generate the heat that they circulate throughout your house. Instead they are able to extract the heat from the air outside and pump it inside. This means that they use much less energy than even the most energy efficient furnaces.

However, heat pumps are only capable of heating your house comfortably when the outside temperature is above freezing. If you live in an area with particularly long and frigid winters, you’ll probably find that you need to supplement your heat pump with another heat source. Because of this, it actually makes little sense to use a heat pump in more extreme climates.

On the other hand, if you live in an area with relatively mild winters, heat pumps can be a great option. They provide a constant flow of warm air to all parts of your home and can also keep you house cool during hot summer months. To cool your home, heat pumps simply reverse the process they use to warm it. They take the heat out of your indoor air and pump it outside. This is a very effective home cooling method and makes heat pumps a great solution for year round comfort.

What Is Forced Air Heating?

Monday, April 11th, 2011

Chances are that you’ve heard the term forced air heating before, particularly if you’re in the market for a new home heating system. But what does that actually mean? The truth is that if you’re asking this question, you’re not alone. There are so many types of home heating systems out there that it’s common to be a bit confused and overwhelmed by it all.

The truth is that a forced air heating system is simply a heating system that distributes heat throughout your house using air to carry it. In this type of system, heated air travels through a system of ducts and is expelled through vents into the different rooms and areas of your home in order to maintain a particular temperature. That temperature, of course, is whatever you set your thermostat to, and when the desired temperature is reached, the heat will shut off until the temperature drops down again.

The main difference between the different types of forced air heating systems is the type of equipment that heats the air. For instance, you could have a gas furnace, an electric furnace, a heat pump or a hydronic coil. All of these are capable of heating air, and when paired with a fan, blower or air handler, can distribute heated air throughout your home.

Many forced air heating systems are remarkably energy efficient and can effectively keep you home comfortable all winter long. Additionally, they are generally made to be incorporated with central air conditioning systems for year round temperature control. Heat pumps are especially convenient in this way, as they’re able to both heat and cool your home depending on the season and your home comfort needs.

Particularly if you already have ductwork in place or if you’re choosing a heating system for a new construction home, it can make a lot of sense to opt for some type of forced air heating. However, if you’re looking to replace an existing heating system in a house that doesn’t already have ductwork in place, the need to put it in can add a lot to the overall installation costs of the system.

What Is a Whole House Pressurization Test and Should I Get One?

Friday, April 8th, 2011

If you have a forced air heating or cooling system in your home, you also have a system of ducts through which that heated or cooled air circulates. And most people don’t give a second though to those ducts. After all, if your heating and cooling systems are working, the ducts must be doing their job, right?

Unfortunately, that’s not always the case. If ducts are not working properly, the whole system will be in trouble, even when you don’t realize there is a problem. That’s why a pressurization test is so important – it provides peace of mind knowing that your home’s ductwork is not only properly installed, but that it doesn’t need any special repairs.

Why Pressure Matters

Your duct system depends on proper pressurization to evenly and efficiently distribute air throughout your home. Leaks, cracks or clogs in the system can disrupt that pressure and lead to uneven or inadequate movement of air through your ducts. This causes problems you may not notice, so if you haven’t had your ducts checked for proper pressure in a while, it’s worth looking into.

Improper pressurization causes symptoms like hot or cold spots in your home or an overall drop in the effectiveness of your home heating and cooling system. When loss of pressure is due to a leak that lets in unfiltered air from outdoors it can also lead to a decrease in indoor air quality. Often these symptoms are easy to ignore. But by doing so, you only allow the situation to get worse.

A whole house pressurization test is the best way to determine the state of your home duct system. By using high tech diagnostic equipment, home HVAC professionals check over your entire system to determine whether you have a pressurization problem. If so they can then quickly pinpoint the source. Once that’s done, the repairs are usually quite simple and you’ll get much more out of your home heating and cooling system than you did before.

Even if no symptoms of improper pressurization in your ducts have presented themselves, it’s worth having one of these tests performed. Especially if you don’t know when the system was last checked, a whole house pressurization test can help uncover small problems before they turn into bigger ones. And the peace of mind this provides is well worth the day it takes to perform the test.