Category Archives: Energy Efficiency

Got Condensation? Here’s Why and What to Do

We all recognize condensation when it forms on a glass of cold iced tea in August. But what does it mean when it forms on the inside of our windows? The same principal is at work on our windows and the iced tea glass: the cold surface meeting the warm, damp air causes moisture to form on the glass.

What is condensation and what can you do about it?

We usually see condensation forming on the inside of windows in the winter, especially at the beginning of the heating season. The cold air outside makes the window cold, and if the warm air inside has too much moisture, it will form condensation. In North Carolina, where the temperature usually rises well above freezing during the day, the condensation will usually dissipate during the day; however, that doesn’t mean that you should just ignore it.

Condensation on the inside of your windows indicates that your indoor humidity might be too high, which can cause much worse problems than foggy windows. Excessive humidity can cause paint to blister, wood to rot, floors to buckle, and insulation to deteriorate. Ironically, it’s often the newest, most energy efficient houses that can be prone to excessive indoor humidity; these houses are “tighter” and don’t allow air to flow freely through the walls to the outside. This keeps heating or cooling inside where you want it, but it also keeps humidity inside. Older houses were often built with more porous materials that allowed water vapors to escape.

Most experts agree on the following scale for indoor relative humidity, based on a range of outdoor temperatures:

  • -30° F or below – not over 15%
  • -20° F to -10° F – not over 20%
  • -10° F to 0° F – not over 25%
  • 0° F to 10° F – not over 30%
  • 10° F to 20° F – not over 35%
  • 20° F to 40° F – not over 40%

(Assumes 70° F indoor air temperature)

Since North Carolina winters are fairly mild, the humidity in your house should be in the 30 to 40 percent range for most of the season.

If your indoor humidity is too high, there are several steps you can take to bring those levels down:

  • Invest in a dehumidifier. They come in different sizes for different-sized spaces and can drastically reduce humidity. You can also buy moisture-eliminating products for high-moisture rooms like bathrooms or basements.
  • Add some air. Open windows for a little while each day, or run ventilation fans if you have them. If you don’t, consider investing in a ventilation system, which will keep your whole house dry.
  • Add some heat. Turning up the temperature will bring warm, dry air into the house, helping to reduce overall moisture.

Seal Your Attic to Save Energy

seal-your-attic-and-save-moneySealing your attic can be a challenging and daunting task for the do-it-yourself person. The benefits will surely be worth the effort you put forth on this project. The ceiling between your attic and your living space is where most of the air leakage from your attic occurs. While your air conditioning is running during the summer, hot air is pulled down from the attic into your living area. During the winter when hot air rises, you lose the warmer air through these air leaks in your ceiling. We will take a look at where these leaks are and what to do to seal these energy-losing air leaks.

Most common location for attic leaks

  • Behind and under knee walls
  • Attic access
  • Electrical wiring holes
  • Pipe holes
  • Recessed lights
  • HVAC air closets

Behind all of your knee walls, stuff the cavities with insulation much the way that your exterior walls were insulated. A knee wall is a short wall usually under three feet  in height that is used to support the rafters in timber roof construction. (You can find images on the internet.) Most attic accesses are located inside the home—usually in a hall or back bedroom. Hot air escapes from the attic into the living area around the attic access door. You can purchase a cover that works really well when installed over your attic access. When you get ready to access your attic, it can be removed and replaced easily.

Another easy fix is to seal around the electrical wiring holes and all of your ceiling fans and lighting fixtures with good quality latex caulking and silicone.  When you pull back the insulation from these fixtures, you can easily see the light from the living area below. Seal these cracks until you do not see any light coming through from the bottom. Recessed lights are some of the most costly lights you can have when it comes to energy loss. The more recessed lights you have, the more heat is pulled in from your attic into your living area. You can make small boxes from foam and place them over your recessed lights (on the attic side), and seal them with a sealer to solve this problem. Make sure that you build the boxes big enough to allow for plenty of room around the fixtures because this type of lighting fixture generates a lot of heat.

Check all of the pipes and exhaust ducts that are coming through your ceilings. You can seal these with a good silicone or caulk. If the cracks are too big to seal with caulking, you can purchase spray foam to fill them. Look into your HVAC closet and see if you can see your attic when you look up. If you can see your attic, you need to seal the top of this closet with insulation or plywood. This simple project can be accomplished in a single day.

If you take the time to follow these simple steps, your house will be more comfortable and your energy costs will go down. Your local HVAC contractor will be more than happy to help you accomplish this task to save you money.

Home Energy Loss: Closing the Envelope

Energy loss is one of the most expensive home challenges that we have today. Unless we take a look at where we are losing most of our money when it comes to energy loss, we willhome-energy-loss not know how much it is really costing. Energy loss is like filling up a bucket with water one drop at a time. After a period of time, the bucket will fill up with water. Every little crack we have around our doors, windows, electrical outlets, and ceiling fixtures all add up to major losses when it comes to energy. Let’s look at the building envelope—what it is and how we can locate and detect energy loss within it.

Think of your home as a closed box. Now take a roof and set it on top of your box. When you set your roof on top of the box, this creates a space at the top which we call your attic. Imagine the area below your roof as a closed-in box. This is your building envelope. The objective is to keep air from escaping or entering into the box we know as our building envelope. We want to keep heated and cooled air in our box and keep outside air from moving in. We will look at the most critical places we lose energy and how to detect them. We will also look at a few easy things we can do to stop this loss.

One of the simplest ways to detect energy loss is to perform a simple test while the air exchanger or handler is running. (Run the test with your air conditioner or heater running.) When your hvac unit is running, there will be a constant flow of air throughout the house and back to your air return. You will notice this from the crack at the bottom of your bedroom doors. Feel at the bottom of the doors when they are shut to see if you can feel air coming from the room traveling to the air return in you hvac. You should have a good return throughout your house. This return keeps fresh air moving and the moisture level down in your house. This air flow is the same air flow that will bring outside air into your home through cracks in the envelope. You will need your hvac unit running during this test; you will also need a candle or incense to carry out the test. Use your candle or incense to check for cracks in your building envelope. The following are the places you need to check:

Around Exterior Doors

Because of all the opening and closing of your doors day-to-day, the weather stripping or doorstops can become extremely worn. Notice where the smoke from your candle goes. If the candle smoke is going back into your home, your air handler is bringing air in from the outside. Check your door hinges to determine whether they are tight. The chief concern here is your weather stripping. It is probably a good idea to replace or add to your weather stripping.

Around Your Windows

Check around the windows to see if you have air coming in from the outside. First check around the inside of the windows against the framing to see if air is coming in from the outside. If you have air coming in from the outside, it is a good idea to use a high quality caulking to seal around the window against your frames. If you have any cracks in your windows, you should replace the window panes. If you have insulated or double pane windows and you see that they are foggy or have moisture between the panes, they need to be replaced because they have lost their insulating value.

Around Your Electrical Outlets and Switches

This may not seem to be a likely pace for air to be entering your home, but you would be surprised. Any air entering your room through your sockets and switches is air being pulled from your attic. During the summer, we know how warm our attics become. That very warm air is being pulled into your home. You can purchase a simple kit at the hardware store that is simple to install. The kit consists of precut foam rubber that you can place over your receptacles and switches. You just simply pull the cover off  your receptacles and switches and place the foam over them, then put the covers back on. This is a great cheap and easy way to fix this problem.

Ceiling Fixtures

As with the receptacles and switches, your light fixtures and ceiling fans need to be checked. It will surprise you to learn how much air is being pulled down from your attics around your ceiling fixtures. These can be sealed in much the same manner as your wall receptacles and switches. Also try switching to more recent types of light bulbs that burn cooler. If you can feel how hot a bulb is burning, just think of the heat being pushed down by your ceiling fans.

These are just a few helpful tricks to help you cut down on the energy loss that occurs through your building envelope. Every little bit is important. The more cracks you seal, the more energy you save. You can lose as much energy through all the cracks combined as through a window or door that has been left open. Try this and you will save money on heating and cooling.


Blower-Door Testing

Blower-door testing is a very adequate way of checking your home for air leakages. The testing-your-blower-doorblower door is an instrument that consists of a panel with a built-in fan that will fit into the opening of your doorway; it is designed to fit any size doorway.  Most often, the test is performed using an exterior door. The fan will pressurize your home to a standard pressure. There are several different gauges that are used to help you monitor the pressures throughout your home to help you find air leaks that are present in your home. Blower-door testing will help professionals to determine if air-sealing work in your house is necessary. If the building needs to be air-sealed, a blower door helps to locate these specific spots.

The blower-door setup includes:

  • a frame and flexible panel to install and seal the doorway.
  • a variable speed fan that will adjust itself according to the inside pressures.
  • a pressure gauge for determining the difference between the outside and inside pressures.
  • a manometer for measuring large air flow volumes.
  • hoses for attaching the manometer to the outdoors and the airflow manometer to the fan.

Compare blower-door testing to inflating a large beach ball that has a leak. When you inflate the ball, it will not take much air to inflate it if it has no leaks. But try inflating the ball if it is full of pin holes or just one large hole. It will take a steady stream of air to keep it inflated. The same thing occurs in your home if you have air that is always escaping—your home will always be at work replacing the air it loses. You will be losing cooled air in the summer and heated air during the winter. Not only are you losing air, but your HVAC or heating unit is running more to replace the air you have lost.

Air pressures in each room of your house can be monitored during a blower-door test. While the blower door is running, you can see how air is escaping from each room. This is the same thing that happens while your air exchanger is running. While the blower-door test is taking place, at some point the operator will put your house through many different scenarios that it could be subjected to in everyday usage.

We know that air moves from high pressure to low pressure. If you have gas appliances, this is a very big issue. The blower-door test can determine if your appliances are properly vented. This is very important because, if the pressure in your house is too low, then there could be a draft pulling the gas fumes back into your house causing carbon monoxide to enter your home. This could be very dangerous! Please check to see if blower-door testing service is available in your area. If you do not know anyone, your local HVAC contractor can assist you in this area.


Checking Your Ductwork for Air Leakages

Ductwork leakages are one of the most common causes of energy loss and poor air conditioning and heater performance. This is a simple fix that you can do yourself and solve the issue of air leaks if you know what to look for and can do a simple test to find the
leaks in your ducts. In this article, we will look at the steps it will take to discover whether you have any leaks and what it will take to fix your leaks. Correcting leaks will be very beneficial to the performance of your air conditioner and also your heating unit. Once you discover the leaks, you can do what you need to do to repair the leaks.

Discover your leaks.

The first thing you will need to do is to check to see if your unit is running. Locate the access to your attic. When you enter your attic, be sure to step only on your ceiling joists or lay plywood down to walk on. The first place to feel for air leaks is where the air ducts first begin to come out of the plenum of your air conditioner. The plenum is the huge bow that is setting on top of your cooling coil. Feel around each duct that is coming out of the plenum. You can feel the air on your hand if you have leaks around the ductwork. Make a note of each leak that you find. The next place to check is at each joint of the ductwork. The number of joints can be different depending on the type of ductwork you have. If you have metal ductwork, you will probably have a joint at least every 10 feet depending on the length of your ducts. If you have foil ductwork, you will not have as many joints, but this type of duct work could develop tears along the lengths of ductwork. Feel around each joint to see if you feel air escaping. Also, inspect the whole length of duct work for any additional holes. The last place you need to check will be where the ductwork attaches to the air vent boxes. Remember to mark or note each place that you feel air escaping the ducts.

Repairing your air leaks.

There are a couple of ways to repair your leaks. One of the easiest and least expensive ways is to purchase a roll of duct tape and place it around the spots where your air is escaping. Although this is a simple fix, it is not one that will last for a long time. The heat in your attic will eventually dry out your duct tape causing it to become brittle and crack. If you have foil ducts, this may be the best way to repair the leaks and holes that may have developed in your ducts. You may have to remove some of the insulation to get to the spot that is leaking. Be sure to replace your insulation. If you have metal ducts, the best way to repair the leaks is by using a mastic sealant. This sealant can be purchased at your local building supplies store. You can take a regular paint brush and brush the mastic over any leaks you may have. When the mastic dries it will become hard and seal off any leaks that you have in your duct work. You may also have to remove some of your insulation to properly apply the mastic sealant. This is the recommended method of leakage repair because it will last much longer than duct tape.

If you cannot perform this procedure yourself, you need to hire a professional to do it for you. This is a simple and inexpensive method that will help to bring your air conditioning and heating units back to peak performance. Get this done now before it costs you more in energy costs.