What’s in an Energy Audit?

Our homes are a great place to start when lowering our carbon footprint. In fact, there are lots of things we can do for our homes, which are energy efficient or environmentally friendly, that have little to no impact on the aesthetic value of the home and come at little to no cost to you. But where to begin? The infamous energy audit of course. I say infamous because there is really no standard for an energy audit. Most homeowners don’t know what they should be looking for when they ask for one, and so most don’t really receive any valuable information about their home once they complete one. Follow along with me, and I’ll explain what all of us should be asking for.

Let me start out by explaining why an energy audit is necessary in the first place. For one, there are a million products out there claiming to be energy efficient and/or green. And while many of these products and their installation providers can make magnificent claims regarding performance, not all products will react the same way in all houses, all climates, and even for all operators. Second, your house works as a system. Changing one thing about your home without addressing others not only has the potential to yield poor results, but can actually create an unsafe indoor environment in the home. Not to mention some advertised energy efficiency upgrades on things like appliances can inversely affect the output of other appliances, effectively negating the expected results on the utility bill. This is typically why most people stray away from efficiently updating their house, or have been extremely unsatisfied with the “greener” products they’ve purchased. But an energy audit is a very helpful tool to use prior to investing in any upgrades, it should allow you to measure the synergy between all your household energy uses and prioritize them. Even if you’re sure it’s your windows which leak like a sieve, it’s important to find out what changing your old windows will do to your indoor air quality, your furnace, and air exchange among other issues. Remember you cannot change one thing without changing the performance of everything. In other words, by changing your windows, you have tightened the structure, which means you won’t need as large a furnace, and without changing your furnace to a smaller size you typically will see no drop in your utility bill.

So what’s in an energy audit? Well, for starters there are a few organizations which teach whole house energy audits and testing. They are the Home Energy Rating System (provided by RESNet), the Building Performance Institute, The Comfort Institute, and the Leadership in Energy and Environmental Design (LEED provided by the USGBC). All of them require at least the use of an infiltrometer blower door as well as some way to measure duct leakage, which in turn is calculated through a software program. If you're not using a company which is a member of one of the aforementioned organizations, make sure they are at least providing a blower door test. Other tools used, however, are duct blasters, combustion analysis, infrared cameras, and static pressure manometers to name a few. Now don’t worry if you’re not quite sure what all of this is, because I’m going to tell you what you need to know by the end of the audit.

A good energy audit should last about three to four hours in the home (it will be shorter the less square footage you have). Also, a good energy audit should provide you with a minimum of the following information:

1) An exact air exchange rate based on ASHRAE, which sets the ventilation standards for buildings. This number will tell you if your home is too tight and needs more ventilation before sealing the home further. You will need this prior to changing out windows, performing any weatherization, and even upgrading insulation.

2) A duct leakage measurement. This will tell you how much air is being lost or gained to the outside through your duct work. Because ducts are mechanically pressurized, they can be the greatest energy loss in the home. You will need this prior to upgrading your furnace.

3) Insulation measurement. This will tell you, along with the air exchange rate, whether you have enough insulation for optimum efficiency and whether you have any infiltration from the outside through your insulation. You will need this prior to adding an air seal and/or adding new insulation.

4) An infiltration tour of the home. Your auditor should allow you to follow them through the house, while the blower door is running, to spot where airflow is coming in at. The auditor should have some kind of smoke generator or even an infrared camera to help illustrate where the air is coming in at. This along with the air exchange will allow you to accurately pinpoint where you should tighten your home.

5) A combustion analysis. This will let you know that all of you gas appliances are venting properly. The auditor may also tell you how much energy is being wasted through draft-vent gas appliances.

6) A static pressure test on your duct work. This will tell you how well air is balanced from one room to the next and why hot and cold spots persist in the house.

7) If an auditor is really good, they will also perform a Manual J heat load/loss calculation on the home. This will tell you whether your heating and cooling equipment is correctly sized for the house.

8) And if an auditor is exceptional, he should also evaluate your landscape water usage.

9) And at the end of it all, your auditor should be able to discuss with you the various efficiency upgrades you can make (many of them you should be able to perform yourself) and help you make a priority of those upgrades based on safety, budget, and indoor air quality requirements.

Notice that I didn’t list kitchen appliances, like refrigerators and microwaves, or Energy Star listed electronics, like your television or computer. I didn’t list any of these consumer goods, because they aren’t typically the energy issue in the house. I mean, unless you’re running a large sports bar out of your house with several big screen televisions running at the same time, only a small portion of your energy bill is spent on running your television. Remember, 70% of your bill (on average) is spent on heating, cooling, and hot water, so taking care of those issues is typically a priority. Also, I didn’t list electronics because you do not need an energy audit to tell you how much energy a consumer good, like a refrigerator, is going to use or is using. That information comes on the box or can be found on the data plate attached to the product. Also, electronics and kitchen appliances don’t change with their environment. Meaning they will use the same amount of energy in Florida as they do in Wisconsin. Your furnace or air conditioner on the other hand may not only work different in different regions, but from one house to the next in the same neighborhood.

Don’t go it alone. Unless you test, it’s just a guess. Find out all the facts before making any decisions on efficiency or environmental improvements. Although there’s typically a cost to an energy audit, it’s well worth the peace of mind you’ll have in knowing not only what the real problems in your home are, but also that you’re making the right decisions in any improvements you decide to proceed with. Nothing’s worse than wading through a million “green” options, and then investing in one that doesn’t yield the results you expected.

You can watch a quick video about a good energy audit, produced by The Comfort Institute at www.climatebydesign.com/videos and click on "Whole House Test."

Being Green: A Statement of a Reality

Sometimes we meet our destiny on the path we choose to avoid it. This seems to be the way our society has approached environmental responsibility. We are doing a lot of things which make a strong statement about ourselves as being “green,” but we’re hardly making a dent in actually becoming a green culture. This is because we typically can’t see the whole environmental system, and so simply choose the solutions that are the most convenient or perhaps make the biggest statement about ourselves. However, convenience rarely is the real solution to anything, and statements fall very short of action…unless you’re trying to sell something.

The cash for clunkers idea may have been a great way for the U.S. economy to sell a few more cars in a tough economy, but it may not have been the best idea to green up our air. After all, cars have very little impact on our surrounding environment from actually driving them. What impacts our earth a great deal though is the building of that car, the transporting of that car, and even the marketing of that car. Not to mention where does that car go once it gets traded in? Back to the earth? I don’t think so. One might guess that it might be better to stick with that old clunker than to throw it out and buy a new one…high gas mileage and all.

But what do we do? I mean high gas mileage cars are a problem. Aren’t they? The reason we perceive this is because we see the exhaust from cars coming out of our tail pipe, and we might even see a slight haze in our city air. This gives us the perceived impression that the majority of airborne pollution comes from cars and trucks. It does not. The fact is the majority of airborne pollution actually comes from large industrial farms and ranches. Cattle put more pollutants in the air via methane than all of our cars combined. However chances of consumers switching from steak to carrots are slim.

So perhaps the reason consumers are scrambling over hybrid cars is because they want to do something, and skipping that burger ain’t one of them. Well, there might be a better way. And it falls on the second biggest pollution source…our homes and offices. Yes, that’s right, our homes and buildings are the second largest contributor to CO in our air. But the problem is that typically greening our homes doesn’t quite make the same statement as driving my hybrid car around town. After all, no one can see my 95% efficient furnace in the basement. But they can see my car with the large hybrid logo on the back of it. However, the earth and consumers would be better served by sticking with an older car (one that didn’t need to be manufactured in the last five years) and update their heating and cooling system instead. That’s right, I said it. Buy a furnace, not a car. 55% of your household energy bill goes to heating and cooling your home, and the leading cause of human generated greenhouse gases on earth is generated from our homes and buildings. You do the math.

In fact, you can even hybrid your home, utilizing basically the same concept as your hybrid car. It’s called a dual fuel system and it heats a home on natural gas when it’s most efficient to do so and then on electric power when that becomes most efficient. The technology is not new and it’s an extremely cost effective way to bring down the utility bill and save the environment. I mean even the manufacture of heating and cooling systems are more environmentally sustainable, and with 100% of an old system recyclable it's also more sustainable to dispose of our old ones. Now, I know, many of you will say that a ground source system would be the best bet. And I agree. However, not every older home is easily converted to a ground source system, and for a lot homes it’s a financial possibility (even if the payback is within ten years). But all homes are easily converted to a hybrid heating system.

But how does this hybrid work you ask? And is it really that efficient? A hybrid simply is a furnace combined with a heat pump (which is like an air conditioner in reverse). The system will move from using the gas furnace to heat your home, to using an electric heat pump to heat it. The point at which the gas turns off and the electric turns on is called your balance point. This balance point is set for your region, utility costs, and typical weather (most times it’s between 35 degrees and 45 degrees). The system will make the utility switch automatically and the balance point can be adjusted to reflect current energy prices. The furnace is up to 95% efficient and the heat pump is greater than 100% efficient because it’s working off of a heat transfer as opposed to generating it’s own heat through combustion. Then, in the summer, the heat pump is capable of reversing and will cool your home (as efficiently as an air conditioner).

In this manner, a hybrid system is even better than adding solar panels to your house. Because unless you’re using solar panels to operate your heating and cooling system, you’re doing very little to either stem the tide of environmental pollution or save money on your utility bill. And yet solar panels are sold much more often than any hybrid system. You have to ask yourself whether adding solar panels is actually an effective solution for your home or whether it is simply making a statement about your “environmental stewardship.” Even windows and doors aren’t a better option than replacing your old heating system. Although windows and doors can change the mean radiant temperature (or the temperature it feels like) in a room, they do very little to actually bring down the cost of running your heating system. This is because windows typically make up a small portion of the wall space in a home. But we sure do buy a lot of windows and doors, because they look good…and they make us feel like we’re contributing to an eco-solution.

So what does green really mean? Most of us know that it probably has something to do with recycling, driving a little less, and probably saving a few whales while we’re at. But most of us don’t really consider the real causes of man’s impact on the environment, or what really is an environmental priority, or what makes fiscal sense to the average consumer. It is only with a systems approach to environmental solutions that our society can become truly sustainable.