Energy AuditHeat and Air

What Exactly is an Energy Audit (done the right way)?

We’ve been in business since July 2012. We’ve completed over 2,500 energy audits. We’ve completed almost 1,000 energy retrofits.

I still get the question…”What exactly is an energy audit?” almost every day.

As much as I preach the word on energy audits, it still feels like 95% of the population is still unaware of what goes on during an energy audit.

 

Safety Tests

energy audit Safety is the #1 priority for us. We complete a series of tests that ensure that you are not living in a “gas chamber”.

  • Gas Leakage. If you have gas appliances, such as a water heater or furnace, we make sure they are not leaking gas. If we do find leaks, we tag them and recommend addressing the problem immediately.
  • Carbon Monoxide and Draft. For those same appliances, we use a combustion analyzer to measure how much CO is being produced. There will always be CO but the idea is to make sure it’s being drafted properly up the exhaust flue pipe and into the atmosphere.

 

Air Infiltration

We use a blower door to adjust the pressure within the house to measure air infiltration as a whole. The blower door is basically a frame and curtain assembly withenergy audit a big fan set up on an exterior door. This equipment allows us to depressurize the house to –50 Pascals. This not only calculates the air infiltration in terms of cubic feet per minute (cfm) of the home but gives us a good indication of the source of the air leakage.

Whew! That was a bunch of scientific jargon. In layman’s terms, we suck air out of the house using the really big fan so we can find all the cracks and holes where air is traveling in and out of your house.

At what level does the air leakage need to be in terms of cfm? There are different math formulas out there that say different things but as a general rule, you want to be around 1 cfm per square foot. So if your house is 1500 square feet and we test the air infiltration at 3000 cfm, there’s about 1500 cfm of improvement that can be done. Why not aim for zero cfm? You still want your house to “breathe” due to everyday occurrences such as aerosol can usage.

 

Duct Leakage

energy audit Another test we do is a duct leakage test. Why is this important? Say you just spent $10,000 on a brand new HVAC unit. The last thing you want to do is have that really nice unit pump air into unconditioned space such as your attic or crawlspace, right?

We use a piece of equipment called a duct blaster to measure the leakage in the duct system. It basically pumps air into the duct system and with the use of a Manometer, it calculates the leakage in terms of cfm. We compare this number to the unit capacity and that depends on the size of your HVAC unit. Again, there’s a more specific math formula out there to determine the exact leakage, but as a general rule, your system’s capacity is about 400 cfm per ton.

So for example, say you have a 3-ton unit. The most the unit can pump through your duct system is about 1200 cfm (400 cfm x 3 tons). And if we test the duct leakage at 300 cfm using our duct blaster, that is 30% leakage (300 cfm / 1200 cfm), meaning that about 30% of the air through your duct system is leaking.

That’s 30% of money out of your pocket!

We want this this to be 10% leakage or less. FYI, our record is 1.5% leakage using our Aeroseal technology!

 

Insulation and Overall Evaluation

Insulation levels are critical for a home’s energy efficiency performance and ties in to the air infiltration and duct leakage. What good is a tight house with a tight duct system without insulation in the walls or attic? Not that good. Without insulation, the heat transfer from inside air to outside air (or vice versa) would easily happen…and quickly.

So one thing we do is to check the levels of insulation in your attic and within the exterior walls. For this region, an optimal level of attic insulation is R38, or, again in layman’s terms, about 11-15 inches of insulation, depending on the type. We like blown cellulose insulation because it also acts as an air sealant.

For walls, we sometimes utilize an infrared camera to see the hot spots to see where the gaps of insulation are present. Some think you have to completely take the sheetrock off the walls to install wall insulation, but there are ways to do it without gutting your house. Our preference? We like to dense pack blown cellulose by drilling holes between each stud bay and packing it in with an insulation hose. And, depending on the construction of the house, there are ways to do it and it still look the same cosmetically as before.

Other things we evaluate are windows and doors. Although, unless they are broken or rotting, we rarely recommend window or door replacements. Go figure since this is the #1 thing people think of in regards to energy efficiency. The fact is that for the dollars spent, it is much more efficient (energy and economically) to invest in air sealing, duct sealing, or insulation when compared to the cost of new windows.

 

Energy Plan and Incentives

The final step in an energy audit is to review recommendations with the homeowner. We put together a plan of action based on our findings. We also do you the favor of putting together the costs associated with those recommendations.

Here’s what’s really cool…as an approved contractor through the local utilities (whether it’s SWEPCO, SourceGas, or Entergy), we calculate what the incentives are for those specific recommendations. And they are instant, meaning we take them net off the quote. There’s no mail-in-rebate and waiting six weeks for payment (with exception of tankless water heater).

 

Ready to schedule an energy audit? If you are in SWEPCO or Entergy service area, it’s free (probably). Click here to schedule.

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