Tag Archives: energy

Blower Door Home Energy Audit

Energy Efficiency, , ,

Blower door testing is the most practical way to predict energy savings from air-sealing methods.how to do a blower door audit

Compare blower-door operation to inflating a leaky beach ball. When you inflate a beach ball, it doesn’t take much effort to fill it if there are no holes present. If the ball has a few pin holes, you have to apply a little more effort because eventually the air will leak out and the ball will become deflated. If there are holes that are bigger (such as raisin-sized holes), you will have to put forth an incredible amount of effort to keep the ball inflated. The total size of the all the holes and the pressure difference between the ball and the outside determines the rate at which you need to blow air to keep the ball inflated.

Like the blowing pressure of your lungs to keep a beach ball inflated, a blower door pressurizes your home by blowing air in or depressurizes the home by sucking air out. Depressurization, which creates a vacuum indoors, is the most common procedure because air comes in through air leaks, allowing you to feel and locate the air leaks in your home. The combined area of the building leaks and the pressure difference between indoors and outdoors determines how much air the blower door moves. The air flow is measured by CFM (cubic feet per minute). The standard for measuring a home’s air leakage is the air flow through the blower door at 50 pascals of house pressure (CFM50)

Blower door testing involves preparing the home for testing, setting up the blower door in a doorway, connecting the gauges, turning on the blower door, and reading the pressure reading on the gauges.

Prepare for testing by following these steps:

  • Close windows and storm doors.
  • Open all interior doors.
  • Disable heaters and water heaters by turning their thermostats down.
  • Cover ashes in wood stoves and fireplaces with damp newspaper to prevent them from being sucked into the home.
  • Shut fireplace dampers, fireplace glass doors, wood stove dampers, and wood stove air intakes.

The blower door operator should slowly bring the house pressure to 50 pascals. This is usually preset with the blower door gauges before he begins. With the house pressure at 50 pascals, the operator notes the CFM50 number from the digital air flow gauge. Then he begins to look around the home with a smoke generator to help find the air leaks in your home. I promise that you will be amazed to discover where the leaks are and the amount of leakage that occurs.

There are several common factors to help to determine the amount of air leakage you may have in your home. This is a little technical, but it will help you to understand the importance of a test of this nature.

  1. The 50 Pascal Airflow Rate: a blower door reading expressed in cubic feet per minute (CFM50) is the actual flow measured at 50 pascals of house pressure.
  2. The 50-Pascal Air Change Rate (ACH50): a blower door reading expressed in air changes per hour at 50 pascals. This is calculated by multiplying the CFM50 by 60min/hour and then dividing by the house volume in cubic feet.
  3. Natural Air Change rate (ACH natural): natural air change is expressed in air changes per hour.

If all of this seems a bit overwhelming, the home energy auditor in your area will know just what to do with all these numbers and formulas. If you are wondering where to find an energy auditor, check with your local courthouse or utility company. Hiring a home energy auditor will be money well spent!

Conserving at Home with Insulation Improvements

HVAC, Uncategorized, , ,

We talked about air leaks and how air moves throughout the house. We will take a look at what insulation is and how important it is to conservation. Heat transmission in the home how insulation can help your homeis the leading cause of winter heat loss and the loss of cool air during summer months. Most single family homes lose more heat through transmission than they do through air leakage. Insulation slows heat transmission through the home’s floors, walls, ceiling, and roof.

Insulation performs the following thermal actions:

  1. Conserves energy by slowing heat transmission.
  2. Reduces the size of heating and cooling equipment that a building needs according to the insulation’s R-value.
  3. Prevents wintertime moisture by preventing low interior surface temperatures.

Insulation also carries with it the following benefits:

  1. Reduces noise.
  2. Helps slow down and prevent air leakage and water vapor transmission.
  3. Helps improve a building’s fire resistance.

Insulation is installed in a building’s cavities, attached to the building frame, or attached to the building’s exterior surfaces. What are some of the characteristics of insulation? Insulation slows heat transmission in an important way. It reduces heat radiation and air convection within the cavities where it is installed. Insulating materials are not as dense as other building materials which are conductors. There are millions of tiny air pockets within the fibers or bubbles in plastic foam insulation. These fibers and tiny bubbles help to slow down the process of heat transmission. The density of the insulation affects its R-value.

Insulation’s ability to slow down heat flow is measured by the R-value. The R-value of any building assembly is determined by the following factors:

  1. Type and density of the insulation.
  2. Air leakage and convection through voids, gaps, or low insulation density.
  3. Water’s presence within the cavities

INSULATION R-VALUES PER INCH

Fiberglass batts, Blown, Board – 2.6 – 4.2
Cellulose Blown – 3.2 – 3.6
Mineral Wool Batts – 2.6 – 4.4
Vermiculite or Pearlite – 2.1 – 2.4
Expanded Polystyrene – 3.6 – 4.4
Extruded Polystyrene – 5.0
Polyisocyanurate Board – 5.6 – 7.6

R-values vary by insulation type, density, and the quality of insulation.

Insulation plays an important role in energy conservation. You can use all the green material you want to use and seal and caulk every split and crack you can, but if  you have no insulation, you have accomplished nothing. When is the last time you have taken a look in your attic? Chances are that if you need to add insulation to your attic, there are other places where it may need to be added, but the attic is the first place to start. You can contact your local contractor for an inspection to see if your insulation needs to be updated.

Air Conditioner Maintenance for the Spring

HVAC, , ,

An air conditioner’s filters, coils, and fins require regular maintenance to work efficiently and properly. You have to maintain these few things in order to get the years of service that spring maintenance for your air conditioneryou need and deserve from the unit in which you have invested your money.  Neglecting these few steps will cause a steady decline  in performance—costing you money. Also, your comfort level will decrease  because your unit is struggling to reach peak performance potential to enable it to work efficiently and properly.

One of the most important things to check on your HVAC unit is your filter. Clogged and dirty air filters will block the flow of air through your unit causing a significant drop in your system’s performance. With the air flow being blocked by dirt and debris, the air that comes through the filter can carry the dust and debris directly to the evaporator coil causing a big drop in performance. Keeping your air conditioner filters clean can lower your unit’s energy consumption by 5%-15%. For central air units, the filters are generally located somewhere along the air return ducts. They are sometimes found in walls, ceilings, furnaces, or in the air conditioner itself. Room air conditioners have the filter mounted on the front of the unit behind the front grill. Some types of filters are reusable; others have to be replaced. The more your unit runs, the more often you need to check the filters. Filters are rated by a Minimum Efficiency Reporting Value (MERV). The higher the MERV number, the more effective the filter will be at keeping dirt out of your system.

Your air conditioner evaporator coil and condenser coil can collect dirt over years of usage. A clean filter will delay this accumulation, but in time, the coil will still collect dirt—reducing the air flow and reducing its ability to absorb heat. To avoid this problem, you need to check the coil at least once a year. A good time of year to do this is in the spring when you do your spring cleanup from the winter that has just ended.

Outdoor condenser units need the same type of attention. You can easily check the coil to see if dirt is collecting on the fins. Check with your local home improvement store or HVAC expert to see if they have a cleaner available for these coils. The aluminum fins on evaporator and condensing coils can easily become bent and prevent air from moving through them. Air conditioner supply stores sell a tool called a “fin comb” that will move or “comb” these fins closer to their original position.

These units also have a condensate drain that can become clogged. Clogged drains prevent the unit from reducing humidity, therefore, sending more moisture into your home. You can occasionally send a stiff wire through the unit’s drain channels to prevent them from clogging.

These are just a few things that you can do to help bring your HVAC unit closer to peak performance to help you save money and conserve energy at the same time.

HAPPY CONSERVING!

 

 

 

 

Seal Your Attic to Save Energy

Energy Efficiency, , ,

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 Efficiency, , ,

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.