Smoke machine used to find leaks
Homeowners are often looking for ways to cut costs. One of the first things that usually comes to mind is lowering bills. While turning off lights, using less water, and using energy-efficient appliances are all great ways to save, it’s time for homeowners to become aware of more important ways to be energy efficient.
By having the right-sized HVAC system and designed ventilation, homeowners can be more energy efficient, save money, and improve air quality.
The state of Texas adopted the 2015 International Energy Conservation Code, which requires new homes to be built a certain way and pass a series of tests. The energy code is designed to improve comfort, indoor air quality, and energy efficiency of homes, according to Kelly Milligan, owner of Milligan Hill Tech Services.
“If you had a house built in say Houston, Dallas Fort Worth, San Antonio, Austin … they enforce the code, so they expect the builder to do the things that the code recommends and they have inspectors that are trained to look for the things,” says Milligan. “The cities of Bryan and College Station have indeed also adopted the energy code, but they have amended out many of the mandatory requirements that are in the energy code.”
Blower door test
While the energy code may not be enforced as heavily in B/CS, Milligan urges homeowners, homebuilders, and everyone else to get educated on the importance of building and testing to the code.
The first step to maintaining an energy efficient home is to have a good, tight envelope. Milligan likes to compare this to an ice cooler. Imagine you are bringing two coolers full of ice to the beach. Close one normally, and stick a pencil in the lid as you close the other. Which cooler’s ice will melt more quickly? The one that doesn’t seal as well, of course. Your house is no different.
“If we have a good tight envelope, we can keep in the cool dry air that we have made with our air conditioner or our warm air that we’ve made with our heater,” says Milligan. “Conversely, if our house is pretty leaky, then what happens is as soon as the A/C or furnace stops, the house is ventilating all the time. At that point we are losing our A/C or our heat and we are gaining things we don’t want to gain, which is like outdoor dust, pollen, animal dander, fungi, and things that come in with the air.”
Milligan and other licensed testers can go into new or existing homes to determine if a home meets the energy code requirements by testing the envelope of the home.
Air gap at a window frame
“The two main tests that we do on the envelope to meet the energy code requirement basically are the inspection — there would be a visual inspection of everything — and then we actually do testing of everything,” says Milligan.
The blower door test allows Milligan to find the leakage rate of a home. With this test, a big curtain with a large fan is installed in an exterior door. Milligan is then able to pressurize and depressurize the whole home to find leaks, cracks, gaps, and other problems. Once depressurized, he can calculate the air changes per hour — a measure for how air moves throughout the house. In order to meet code standards, homes in B/CS must have five air changes per hour or less.
Not only can air leak from gaps and cracks in windows and doors, but ventilation, too. Most houses in Texas are designed to have attic ventilation, according to Milligan.
“A ventilated attic means that we have an attic assembly where the insulation for the house is actually right at the ceiling or on the attic floor, and the attic itself has large vents,” says Milligan. “We need ventilation in the attic because that’s where a lot of heat builds up and that’s where moisture finds its way from out of the house. So we want that ventilated to take that heat and that moisture away. The cooler the attic stays the less of an effect that has on the house through the insulation right below it.”
Missing insulation
Since the ventilation and the HVAC work together, it’s important there aren’t any leakages from either to create the best air quality and energy efficiency.
“The house is a system,” Milligan says. “When the house loses air like that through a leak, it has to make up for it.”
Unfortunately, B/CS is the largest metroplex in Texas that does not participate in mandatory testing, according to the South-central Partnership for Energy Efficiency as a Resource. Houses still have to pass a visual inspection, but unless builders or buyers request it, the house will not be tested. “Without testing it, you don’t know,” he says.
Milligan has spent the last two years testing newer homes and creating a database. “I’ve tested about 46 homes; of those homes, about a quarter of them fail the blower door test,” he says. “About 25 percent of the homes, the envelope is not tight as the energy code would like it to be. … What’s more alarming is the fact that of those houses that I have test for the ductwork, we have 100 percent failure of all the houses tested to meet the duct testing requirements for the energy code. So, that leads us to believe that, as the old saying goes, ‘If there is no enforcement, there is no compliance.’”
Blown in attic insulation
The good news is it’s not too late to fix the problem. New and existing homes can be tested. Sometimes the problem is the designed ventilations, and other times the HVAC system is too large or too small for the envelope of the home. Other resources, such as Energy Star, have ways for homeowners to improve their energy efficiency as well.
However, the most important step to take is education.
“It’s all things buyer beware,” Milligan says. “The more informed a consumer can be, the better decisions you can make. I would ask that consumers get more educated in the second cost of homeownership. Everyone focuses on, ‘Well, this is how much the house costs to buy.’ That is your first cost of ownership. The second cost of ownership is: How much does it cost to operate that home every month and perform the maintenance on that home? So an energy efficient, durable home will have less maintenance to be done on it and will make it cheaper in that respect. And, if it is done right and tested, those houses are typically more comfortable, healthier, and more efficient.”
