Indoor Air Quality

I was reading a few articles this morning from, of all places, the Alaska Building Science news! I know this is a long way from home and the building methods are very different, for example R-140 ceilings and 28” thick R-90 walls, but the desire to live cheaply and comfortably is universal. Yes this was a test home, but R-50-60 building envelopes are the norm; it’s a lot colder up that far north.

The building science part was very interesting and certainly unique, but the article I read about indoor air quality is one that I think warrants mentioning to everyone, regardless what part of the globe you call home.

We have all heard about the dangers of CO (Carbon Monoxide) and detectors are cheap and readily available. Most of us are aware of the dangers of Radon as well, but what about a very common hazard we rarely give a second thought: household cleaners. Below is part of an article by Rich Seifert titled How Important Is Indoor Air Quality…

“Perhaps the most unsuspected dangers for IAQ (indoor air quality) in homes are the household cleaners. The fundamental problems with these items are the fragrances used in them. Unfortunately for us, the consumers, it is not required by law to disclose the ingredients in the fragrances used by the cleaners. The Fragrances may contain 50 or many more organic substances. Some can be allergenic, and that may be the least of the hazards. This concern also applies to plug-in air fresheners since the fragrances in these products don’t have to be exposed. The plug-in is used to evaporate and fill a room with a fragrance in order to mask other odors in the room. Since other odors could warn you of other hazards, like mold or moisture problems, it is unwise to use heated plug-in fragrance devices to mask odors in your house. You may be adding to a problem and making your house unwittingly worse for allergy suffers since you don't ’now what else you are being exposed to.”

This is great advice whether you live in Alaska or Georgia and I will add one thing to the above paragraph. When using chemicals and fragrances always remember that unscented is also a scent. It probably takes as many, or more, organic compounds combined to remove the scent from the chemicals used to make the cleaning product or air freshener!

Understanding SEER Rating

In the middle of the real estate boom, the United States Department of Energy mandated making the minimum SEER rating of our HVAC systems 13 SEER or greater . This would go in to effect in January of 2006, and many builders and HVAC companies were warehousing older 10 SEER units for cheaper installations and parts. I was a real estate agent at this time and the decision was not popular with many of my colleagues. “It’s just going to make homes more expensive” and “my old unit works just fine, why does the government have to get involved” were the most common complaints. We didn’t like it, but honestly I don’t think any of us could have explained what a SEER rating even meant!

SEER stands for Seasonal Energy Efficiency Rating and is an average of the unit’s cooling efficiency. Simply stated, the higher the SEER, the more the efficient the unit. As a mathematical formula it would read:

Total cooling output over the cooling season / total energy input over the cooling season

Luckily many of the older lower SEER units installed before 2006 are long gone. The average lifespan of an AC unit is 10-15 years, but it is possible that if you are still running one of the old ones it could have a SEER rating of about 6. It is not uncommon today to find units operating at a SEER as high as 27 and while the upfront cost is higher, you will pay less over the course of its lifetime.

Below is a comparison of the cost of operating a 6 SEER unit compared to a 13 SEER unit. Both are 3 ton units (36,000 BTU) running 8 hours per day. We’ll say that the cooling season is 4 months long and the average utility rate is .10 cents per kilowatt hour.

6 SEER

36,000 BTU/hr. x 976 hours / 6.0 SEER = 5,856,000 watts / 1,000 (to convert to KW) = 5,856 KW x $0.10 = $585.60 per year

13 SEER

36,000 BTU/hr. x 976 hours / 13.0 SEER = 2,702,769 watts / 1,000 (to convert to KW) = 2,703 KW x $0.10 = $270.30 per year

This is an annual savings of $315.00 per year, or $4725.00 over its average 15 year life span. Rebates from your local power companies will often bring the cost of the higher SEER units more in line with the minimum SEER models, so be sure to check before purchasing.

Even if you are not ready to replace your older unit, you might want to consider having your duct system tested. 20-40 percent duct leakage is not uncommon and a homeowner repair is not difficult. Doing this now will ensure that you are milking every last ounce of cool air from your existing system. It is likely you will begin to save money without replacing your existing system! 

Should I turn the lights off when I leave the room even when using CFLs?

This is a question that I am asked on almost a daily basis and quite honestly I had no answer. I researched the question online, and below is a link to the best explanation I discovered.

http://greenbuildingelements.com/2008/04/07/when-to-turn-off-fluorescent-lights/

Basically the article says that there is no need to worry about how many times CFLs are turned on and off. If you are going to be away from the fixture more than 5 minutes, turn it off. There is concern that this will shorten the lifespan of the bulb, but it is not an important one.

One of the aspects of turning off lights that is not discussed in this article is the fact that when the light is off no electricity is being used. I know this seems like an all too obvious observation, but think of it this way; most of the electricity generated in the United States is done so by burning coal. For every kilowatt NOT used, less (or no) coal is burned. Even if you shorten the life of the bulb by repeatedly turning it off and on, it will still last longer and use less electricity than a normal incandescent bulb. When it is off it uses none!

Invariably, when CFLs are mentioned, the conversation will end up in a discussion of the hazards of mercury. CFLs do contain small amounts of mercury and special care is needed when disposing of them. But one of the main contributors of mercury in our environment is the burning of coal. I can’t give hard numbers, but I would imagine it would take more than a few broken CFLs to come anywhere near releasing the amount of mercury that a power company coal stack emits in an hour! When you leave the room, turn off the lights!

Will A Metal Roof Save On My Heating And Cooling Bill?

       

The answer to this question is yes and no; it will save money on your cooling bill, but the effect will be negligible on your heating bill.

 In addition to no maintenance costs, a metal roof, especially aluminum, can lower your demand for air conditioning. According to the Florida Solar Energy Center, installing a simulated cedar-shake aluminum roof can reduce heat gain from the roof down through the ceilings by as much as 34 percent. Steel roofs, although not as efficient as aluminum, are also better than asphalt shingles. A metal roof cools down in five minutes once the sun sets.

An Energy Star rating for all roofing products is based on TSR (total solar reflectivity). Classic black asphalt shingles will have a TSR of only 0.05, while a quality aluminum roof will have a TSR of around 0.40. The larger number will mean that the roofing materials remain cooler and less heat will be radiated down through the ceilings to the living area. Also the underside of the aluminum metal surface has a lower emissivity (the ability to emit heat) than asphalt shingles, so less heat radiates downward.

Follow this link to an Energy Star roof calculator: http://www.roofcalc.com/    before making any roofing decision.

Metal roofs can save you as much as 20% on your summer utility bill by keeping your attic several degrees cooler. You can increase the savings by adding a radiant barrier under the metal roof to reflect even more heat rays.  A radiant barrier http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11680  can also be installed inside the attic as a retrofit on any metal or asphalt shingle roof. Avoid a horizontal application because dust from your insulation will reduce the radiant barrier’s effectiveness over time. The best application will be between the rafters up against the underside of the roof.

So the answer to this question is yes, a metal roof can reduce you energy bills. I will add that a radiant barrier alone will reduce your energy bills as will lighter color asphalt shingles or shade from large trees. A new roof can be an expensive proposition and it is always wise to calculate your ROI (return on investment) http://www.greenandsave.com/master_roi_table.html  on any improvement.

Energy improvements on an older home: where to begin

             Energy improvements on an older home: where to begin

Before the fuel crisis of the 1970s most Americans never thought twice about their home’s energy consumption. Many lived in older homes that had been retrofitted with electricity, indoor plumbing and forced air heating and cooling, and how efficient these systems were was less important than the fact that were simply there. Efficient and installed were synonymous!

The air conditioner brought an explosion of growth to the southern half of the United States that had once been declared “too hot for civilized people” to live year round. These systems were installed in homes that were not designed for such modern equipment and the results were mixed. Basically as long as the system was blowing cool air the house was cool. These homes were just not good at holding the cool air. So let’s discuss a few ways to bring these homes up to reasonable energy consumption levels. 

Below is my priority list, but it is okay to skip around some if you can’t afford the next measure.

1.     Seal all balloon framed walls and attic penetrations (plumbing, wiring, HVAC).

2.     Seal and insulate attic hatch.

3.     Seal and insulate knee walls in attic area.

4.     Insulate attic to R-30.

5.     Seal and insulate all forced air duct work.

6.     Install vapor barrier in crawlspace.

7.     Seal all plumbing and wiring penetrations in crawl space area.

8.     Caulk and weather strip around doors and windows.

9.     Install bath fans and range hood.

I would consider this list of priorities as a baseline before I purchased any type of energy saving appliances. Of course if the appliances or HVAC system need replacing before you complete the list, do so with Energy Star models. 

I would also consider having a blower door test conducted by a qualified individual before attempting any work. By doing this problem areas can be identified and large amounts of air infiltration/exfiltration can be eliminated. It is a good idea to have the testing done by an impartial person and not a company that wants to sell you the improvements.

The CFL

                                                                    

The energy savings realized by replacing your existing incandescent light bulbs with compact fluorescent (CFLs) boils down to simple math. Even at the old price of $5 per bulb, a fixture that operates 10 hours per day will pay for itself in less than three months. But given today’s price of around $1 per bulb, it makes sense to replace those even in fixtures that are infrequently used. It may take a little longer for the simple pay back to be realized, but there is another hidden benefit of the CFL that these numbers don’t reflect.

When the government attempted to step in and mandate CFL usage they were met with stiff opposition. Faced with extinction, the companies that manufacture the 100 watt incandescent bulb found a new and legitimate use for their products and granted them a new name. They will now be known as “heat bulbs”. As a survivor of more than a few hot Georgia summers, this name itself tells me all I need to know about incandescent lighting!

Incandescent lighting produces light as a byproduct of producing heat. Only 5%-10% of the electricity used is transformed into visible light. How much harder will your air conditioner run just to combat the heat generated by the bedside lamp you read by each night? Multiply this by the lighting used throughout the home and you have measurable numbers. Why heat it up before you cool it down?

A CLF contains 5 milligrams of mercury, so a little extra care is required when cleaning up a damaged or broken CFL. Sweeping up the fragments with a paper towel and sealing them in a plastic bag is recommended when disposing of broken bulbs. Follow this procedure with diligent hand washing and you should be okay. Some studies show that you are actually exposed to larger doses of mercury when eating a tuna sandwich!

I replaced all forty bulbs in my home with CFLs over two years ago and I have had to replace only one! They produce cool light and last a very long time. With LED technology on the horizon pricing for CFLs has never been lower. It now makes sense to replace every bulb in your home!

Ceiling fans

It’s almost impossible to find a modern home today without ceiling fans. They have been around for quite some time, but gained additional popularity in residential housing during the 1980s. Before this time they were expensive and mainly seen in commercial applications such as restaurants and warehouses.  The residential fan’s newest feature was a switch to reverse blade direction to push air down in the summer and pull air up in the winter. This was somewhat of a “sales pitch” intended to give the fans a year round purpose and justify the cost, but most now agree that they are most effective in summer only.

Today a fairly high quality ceiling fan (with light kit) can be purchased for about the same price as a nice light fixture alone. While most consider them purely decorative, a ceiling fan can help you save money on your cooling bill. Sitting under a whirling fan can actually make the air that touches your skin feel 4-5 degrees cooler and this will often allow homeowners to set the thermostat slightly higher.  A typical rule of thumb is that you will save 1% on your energy bill for every 1 degree higher you set the thermostat!

One last note on ceiling fans deals with their installation. If you have a very tall or vaulted ceiling, consider lowering the fan closer to the living area. Down rods are readily available in several colors at hardware and home improvement stores and are quite simple to install. Don’t get it too close, but the closer the fan is to the occupants the more air they will feel. But when you are away, turn the fan off. Remember…Ceiling fans cool people not rooms.