Q: With energy prices soaring and everyone trying to do their part with conservation, what are the top 5 tips or strategies you would recommend to the owners of large homes to be as energy efficient as possible?
A: To many clients’ surprise, energy efficiency and comfort go hand-in-hand, so you don’t have to give up comfort to get more efficient. The most efficient homes are those that effectively manage indoor air quality, namely humidity, filtration, and infiltration. Here are several tips.
1. Maintenance. Get on a solid, thorough maintenance schedule. Work with a qualified professional HVAC company to put a service agreement in place that will address routine maintenance and spot any issues before they lead to costly and inconvenient system failures. Make sure your service agreement includes the following:
a. Cleaning the outdoor condenser coils and maintaining the electrical components on the outdoor unit. The air conditioning system is the single largest consumer of electricity in most large homes during the summer, and in many southern markets the systems run 9-12 months a year.
b. Inspect and clean the drains. Air conditioners remove humidity from the air and produce constant water run off. Drains can and will clog in all homes if left alone. Proper float switches should be installed in multiple key locations do shut the system down if water backs up, which is particularly important to families who travel extensively or are gone for long periods of time. The trickle from an air conditioning system can flood an entire home over the course of a summer.
c. Keep the filters clean. The contractor should replace the filters, as needed. Each filter has a recommended schedule, but clients should know that they only need to replace the filters when they are dirty. Large homes often have dedicated housekeeping staff, who keep the house cleaner than most average homes. As a result, your filters may last longer than the manufacturer’s recommendation. Common sense prevails here.
d. Don’t forget the furnace. Be sure your service includes a furnace inspection. Not only is proper operation critical for efficiency and performance, maintenance of the heating system is more about safety. Many older systems, even if they have been converted to gas, require careful attention, and more modern equipment often does not last as long, meaning they are more likely to wear out and fail.
2. Thermostats. In larger homes it is not uncommon to have more than half of the home go mostly unused, particularly in cases in which the kids are gone. A digital thermostat should be programmed to only condition the areas you use, when you use them. If you are leaving for several days or longer, use the vacation settings if available. For the areas or times that you are not in the home, set the thermostat to 78 degrees in the summer. Do NOT turn the systems up too high or completely off…turning them off can create humidity problems affecting the house and its belongings. As well, keep in mind that it can take a half day to a full day to cool a large home 10 or more degrees.
3. Ductwork. Ductwork is considerably less expensive than the mechanical equipment, and it can contribute significantly to efficiency and comfort. Be sure that your ductwork is sealed and air tight. With even minor leaks, the return ducts may be pulling 100+ degree air from the attic, making the system work much harder. Look for loose tape, gaps, or deteriorated materials. Minimize flexible ductwork, as it does not carry the same capacity of air. If you are unsure about your ductwork, have your HVAC company inspect your entire duct system and offer recommendations. Also, keep in mind that your duct work may warrant inspection, even if it is new. Multi-million dollar homes still often have substandard duct systems.
4. Spray foam insulation. Spray foam insulation on the underside of the roof can contribute to comfort, efficiency, as well as air quality. Sealing up the attic and roof can eliminate the infiltration of dust, dirt, and other debris that might otherwise be coming with unconditioned outside air around every crack and orifice.
5. Preconditioning / indoor air-exchangers. The more tightly sealed the home, the more important it is to be sure there is adequate fresh air coming in. Air exchangers feed your system sufficient air to keep them running efficiently, as well as take out stale indoor air (which may contain formaldehyde, volatile organic compounds (VOCs), and other toxins released by building materials - particularly in newer homes). They pass the air through a filtration system and dehumidifier.
These tips are generally the most cost-effective and easy to make in a home, but ultimately, nothing beats a system that has been specifically designed to work together to meet the family’s needs. Properly sized and rated equipment will work together more efficiently than any single fix. If your systems are more than 15 years old, work with your HVAC contractor to start planning a total system review to avoid a patchwork of inconsistent heating, cooling, humidification, and dehumidification components. New high efficiency, multi-stage systems can reduce your monthly energy bill by more than 20% as well as keep your home more comfortable.