Archive for the ‘energy efficiency’ category

Quick Tip #37 – Can Lights? Make Them Green

October 27th, 2014

Can lights or recessed ceiling lights are a common design feature in modern residential construction. They are also common in older custom-built homes. They provide a unique lighting pattern without the glare of a fixture, but they may also waste energy.

You have several options when replacing the bulbs (lamps) in can lights. Don’t use a common “A” type bulb; it will not direct light out of the fixture. Most of the light is just wasted inside the can.

Consider a spot or flood lamp that reflects and projects light out of the can, such as a parabolic aluminized reflector lamp (also called a PAR bulb). For a “green” step up, consider a parabolic lamp, which has a curved reflector that projects even more light out of the can into a smaller pattern.

For a choice that’s even more “green,” use a compact fluorescent spotlight or reflector lamp. These compact fluorescents save about 75 percent in energy costs and last much longer than incandescent bulbs. They also create less heat in the room – heat that must be removed with air conditioning in hot climates.

While light from fluorescent lamps may look a little different at first, their light color and quality have greatly improved in recent years. Look for “warm” color lamps or “color corrected” lamps for a more pleasant light.

E123C - Can Lights - Proper Bulbs_300dpi

Quick Tip #35 – A Ton of Cooling

October 16th, 2014

Ever hear of a two- or three-ton central air conditioner? Does that mean a two-ton air conditioner weighs 4,000 pounds? Is the term related to cooling capacity, or is it a random term that tech folks use to impress us?

When engineer Joe Cool (at least I think “cool” was part of his name ) developed the standards for measuring mechanical cooling, ice was commonly used for cooling. You know, in the old days, food was stored in the ice cooler, and there was no air conditioning. So Joe decided that the cooling capacity measurement should relate to ice.

A standard was set equating one “ton” of cooling to the amount of energy needed to melt one ton (2,000 lbs.) of ice over a 24-hour period. For tech folks: the exact figure is 12,000 btu per hour.

So what is a btu? It stands for British thermal unit, and we will cover that detail in another tip. Just remember: one ton of cooling equals melting one ton of ice in 24 hours – 12,000 btu per hour.

To put it another way, the change of phase from ice to water requires 144 btu per pound or 288,000 btu per 2,000 pounds.

A047C - A Ton Of Cooling_300dpi

Quick Tip #24 – Compact Fluorescents – Yes, They’re a Good Deal!

July 29th, 2014

E124 - Compact Fluorescent LampsOK, for many years compact fluorescent lamps (CFL) were a bit of a pain. They provided an eerie color, took a long time to reach full brightness, never worked outdoors in cold weather, and failed early.

Most of those problems have been solved in the last 20 years. Now it’s hard to resist these lamps, which provide the same amount of light as incandescent lamps for about 25 percent of the energy cost. They also generate about 75 percent less heat inside an air-conditioned space, which is important in areas where air conditioning is used often.

They are color-corrected to provide a natural color. When you purchase the lamps, look for the “warm white” or “natural” color notation on the packaging. The color-corrected CFLs really do have great color. They’re available as spotlights and floodlights, and there are special versions for circuits with light dimmers. The bulbs are small enough to fit in most household lamps and fixtures.

If you do the energy calculation, you’ll see there is a great payback for substituting CFLs over incandescent bulbs. They also last about six to 12 times longer than incandescents.

Quick Tip #5 – Save Money with a Filter Change

March 10th, 2014

H009Maintaining the filter on your air conditioning and heating equipment isn’t fun or glamorous. So why bother? Because a clean filter allows for proper air flow, and that makes the equipment run efficiently, saving you money. Also, a clean filter helps your system perform better, so your home environment will feel more comfortable.

And because a dirty filter restricts air flow and can make a heating unit overheat or an A/C unit freeze up, maintaining the filter helps you avoid a service call.

Filters come in various types, so take a look at your equipment. If you have a cleanable filter, note on your calendar when cleaning is due. Otherwise, buy an appropriate replacement filter to have on hand when you need it. Filters are inexpensive and should be changed or cleaned when they are visibly dirty. When you do change the filter, note the directional arrows on the side. Place the filter so that the arrows point in the direction of air flow.

By Tom Feiza, Mr. Fix-It

Quick Tip #4 – One Cold Room

February 21st, 2014

H020Does your home have one room that’s always cold? Is there very little air flow from the heating grill, even when it is fully open? The culprit may be a heating supply duct that’s been closed.

In the basement, find the main warm-air supply duct, which originates directly above the furnace. Often this is a rectangular duct running down the center of the basement. It may branch off into smaller circular ducts serving individual room registers.

Where the round duct attaches to the rectangular main, look for evidence of a duct damper: a wing nut around the end of a quarter-inch threaded rod. At the end of the rod, you’ll see a screwdriver slot.

If this slot is perpendicular to the small round duct, the damper is closed. If the slot is parallel to the duct, the damper is open. You can loosen the wing nut and change the position of the damper. Then secure it by retightening the wing nut.

If opening the damper solves the problem, great. If the room is still cold, you may need to partially close other dampers to direct more air to the cold room. Often, dampers fit loosely, and even when fully closed, they can leak lots of air.

By Tom Feiza, Mr. Fix-It

Insulation Near a Fireplace?

December 17th, 2013

Question:

Can I insulate the underside of my first-floor fireplace chase? I would like to put batt-insulation, and a ceiling below the fireplace. I currently use the area as a storage closet. The area is very cold, and the air seems to migrate upstairs. I also get frost above the basement wall, on the framing. The fireplace is ~20 years old, and non-gas.

–Eric

Answer:

You’ll need to check on the installation requirements for your specific type of pre-fabricated fireplace. They must be installed per specific installation requirements. In general, they require clearance around the metal firebox, and around the metal flue that is routed up through the boxed-in chimney chase. I don’t think your real problem is in the basement. I think the real problem is the exterior wall behind the fireplace. Insulating below the floor will be of little value.

The areas around the fireplace can be a big heat-loss, because the outside wall behind the fireplace may not be properly insulated. The exterior wall should be framed so that it can be insulated and sealed like a typical exterior wall. This does not always happen when the wall is buried behind a manufactured fireplace, and brick facing.

F007 - Metal-Framed Prefabricated FireplaceThe area below the fireplace (above the foundation wall) should be independent from the fireplace installation. Ice in this area (and around the sill/band joist) occurs because air moves through the fiberglass batts, and moisture condenses on the cold surface.

The ideal fix at the top of the foundation wall is to have the area sealed and insulated with spray foam. This will seal the air-leaks, provide a vapor-barrier, and insulate the area.

If you want to work with fiberglass, you need to remove it and caulk any gaps in the area around the sill-plate to the sub-floor. Fill the space with tight-fitting fiberglass, then seal it with drywall and plastic caulked in place on the heated side. It sounds like the foam is a much better option.

–Mr. Fix-It

Leaks Coming From the Attic

November 18th, 2013

Question:

I have frost in the attic of my five-year old, two-story house. I noticed a small leak coming out of the can light in the bathroom. Do I have enough insulation in my attic? I have 2″ x 4″ ceiling rafters, with ~16 inches of blown-in white insulation. I also have a ridge-vent running along the peak. Could heat be exiting through the attic door, exhaust vents, or can light, then melting the frost?

–Kevin

Answer:

Most folks who study moisture and home systems would identify your issue as an air-leak problem into the attic. Warm, moist air from the heated space is escaping into the attic, and moisture from that air is condensing on the cold roof deck. This may show as ice in very cold weather, and water in warmer weather. The problem is not insulation.

 

I025 - Air Leaks - Top of Wall

You need to search for air leaks at can lights, plumbing, electrical penetrations, chimneys, trap doors, etc. Seal up the air leaks, and the problem will be solved. Sounds easy? It’s not. You need an experienced contractor, who knows how to locate and seal the leaks. However, stopping theair leaks will save lots of energy.

I suspect you saw the leak at the can light because the light heat was melting the frost. The plastic vapor barrier is also open at the can light. If you want more information on attic insulation and air sealing, read my article Insulate Your Attic – But Don’t Stop There!

–Mr. Fix-It

Energy Savings in Window Replacement

June 7th, 2013

QUESTION:

I have an old farm house with some updates. The first floor has double-pane windows (15+ years old), and the upstairs has old single-pane windows. We replaced 11 windows with Energy Star-rated windows. I reviewed my energy use, and found that it did not decrease at all. Could I have been sold bogus Energy-Star windows?

–STU

ANSWER:

Evaluating any energy improvement in a home is difficult. You need to compare energy use based on similar heating degree days. Degree days take into account the dramatic variations in temperatures. But you also need to consider wind, interior temperatures, heating plant performance, air leaks, ventilation, use of fireplaces, and other variables.

New, Energy-Star rated windows with thermally insulated glass will normally perform better than old wood windows. If they are rated and certified, the window should not be an issue. But on-site installation and air sealing is a key detail affecting the window and wall system performance.

If your old single glazed windows were tight fitting and you had tight fitting wood storms, the actual change in the heat transfer through the new windows will not have a large effect on your energy usage. The replacements just don’t save much money if the original windows were in pretty good shape.

If you were given some type of guarantee or promise from the window installation company, I suggest you contact them with your concerns and read all the claims and fine print.

In my mind, the biggest reason to replace old damaged wood windows is lower maintenance, ease of operation, appearance, comfort, and finally energy savings.

–MR. FIX-IT

 

Insulating Hot Air Ducts – Energy Saver???

April 30th, 2013

QUESTION:

Does it save energy to insulate hot air ducts in the basement? I have long runs of ductwork,  and work in the basement often.

-DAVE

ANSWER:

Insulating the heating ducts saves very little energy in a home with a full basement, and the heat ducts in the basement space. Essentially, the basement is within the heated space of your home. The answer would be different if the ductwork was outside the heated space (e.g. the attic).

I would be concerned with any major air leaks in the ductwork – those should be sealed or caulked so the heated air moves to the correct area of your home. With most full basements, a heated space above, and some ductwork leaks or supply vents keeps the basement a few degrees below the heated space. Allowing some heated air to leak helps heat the basement, and tempers the air below the fully heated space – not a bad thing.

 

I026 - Foam Insulation_Seal Box Sill

 

For energy-saving and comfort, look at insulating/sealing the area above the basement wall, up to the sub-floor. That area is a potential for a huge heat/air loss to the outside. The best insulation and sealing here would be a spray foam, from the top of the basement wall to the sub-floor (if it is allowed by local code officials). Also, check the basement windows – are they efficient?

–MR. FIX-IT

More Insulation … More Savings?

March 1st, 2013

QUESTION

I am building a commercial building with a rubberized flat roof. I want to go to R45 insulation on the roof, but my friends say that after R23 you don’t see a return on your investment. Is that true?

Also, what is the best way to insulate the walls of a commercial building? What is more efficient – an exterior HVAC system, or an interior in a basement? I am looking to save cost for natural gas, so any advice would be greatly appreciated.

PAUL

ANSWER

I009 - Insulation – Diminishing ReturnIn most cases, an insulation value of R38 is recommended for roof or attic insulation in residential and commercial construction for northern climates. But, the insulation will also depend on the usage of the building, and how warm it will be kept. The wall insulation is dependent on the type of construction and finishes.

A heating, ventilation and air conditioning system is always more efficient if you can keep the complete system (and the ductwork) inside the building’s conditioned air space. Units are much easier to service if they are in the space, and if duct leaks occur, they will leak into the space. Roof-mounted units are often used to save interior space, but are never as efficient.

Contact the folks at Focus on Energy. Check their programs for energy efficient construction. They are residential and commercial experts who have lots of experience with saving energy. They also have rebate programs for energy efficient construction. With our economy, and the increasing cost of energy, it will be a good payback to build an efficient building.

MR. FIX-IT