For most homeowners, heating is a fairly substantial cost for half or more of the year, and if your home isn’t designed with efficiency in mind, you’re almost literally burning money. When our friends and neighbors ask us for tips to lower energy bills, we almost always advise them to take a look at their heating costs. That often means investing in insulation, installing a ceiling fan to complement the heating system and even investing in a high-efficiency natural gas furnace or boiler.
Why do I Need a Heat Recovery System?
All of those tips to lower energy bills are helpful, but there’s one dedicated system that can really make a huge impact on your heating costs and improve your comfort to boot. That’s a heat recovery ventilator. At Griffith Energy Services, we highly recommend heat recovery technology.
The Need for Efficiency
If necessity is the mother of invention, cost control is the mother of efficiency. Over the past 40 years or so, increasing fuel costs have been the big impetus for many people to work on creating new cost-cutting solutions. In particular, builders started to eliminate drafts by sealing up cracks, working with new materials and insulating more thoroughly. Those steps worked, to a degree, and heating costs started to come down. Then, homeowners started to ask whether those changes were really worthwhile.
The problem with just sealing drafts is that, while air leaks do impact heating and cooling efficiency, they also let fresh air into the home. Seal up the cracks, and you’re left with old, stale air to breathe. Those builders may have fixed an efficiency problem, but in the process, they created a comfort problem. In short, homeowners were left with a tradeoff between efficiency and comfort, which certainly wasn’t a great proposition.
Fortunately, the HVAC industry came up with a solution. The idea was simple: let stale air out of the house, but don’t let it carry heat out in the process.
How Heat Recovery Systems Work
A balanced ventilation system is a machine built to bring fresh air into the home in the most direct way possible. One fan blows stale air out of the house; the other brings fresh air in from outside. As compared to natural ventilation such as windows, balanced systems provide the same level of ventilation regardless of wind and weather conditions outside. The downside of such a system is that, if the outside air is cold, it needs to be heated up, and that costs energy and ultimately money.
Dedicated heat exchange ventilators use the same basic principle as balanced ventilators. One fan brings air in, one fan lets air out. The key is that the ventilator also features a heat exchange core that warms up the outside air before it enters the house. Essentially, the core takes heat from the outgoing air and transfers it to the incoming air, which stays just as fresh and clean but doesn’t lower the indoor temperature.
The upshot is that less energy is wasted on heating up air that’s just going to be blown out of the house anyway. The ventilator catches that heat and transfers it to the air that’s coming in, saving you money.
Advantages of a Heat Recovery System
Of course, the main benefit of heat recovery is that there’s less wasted heat, which means less money wasted on fuel costs. With a new ventilator, you can keep your windows closed, seal up drafts, insulate your home and still breathe fresh air every day. Despite their name, heat recovery ventilators help your cooling systems as well, as they take heat from incoming fresh air and transfer it to cool, stale air that’s on its way out. That means every heating and cooling in your home will benefit from the energy recovery.
If you live in a newer home that’s well-insulated and sealed up tight, then the extra fresh air you’ll get from a heat recovery ventilator will be well worth the cost. No longer will you have to choose between breathing stale air and losing heating or cooling power by opening a window. Even in older homes that have a good deal of “natural” ventilation from drafts and cracks, your comfort may vary substantially depending on the weather outside. The great thing about a ventilator is that it will adjust its output to suit your home’s needs, keeping you breathing easy even in calm weather.
Speaking of adjustments, most modern ventilators are fully adjustable. A typical heat recovery system can move up to 200 cubic feet of air per minute, which is plenty for most homes, but they don’t have to run at full capacity all the time. Instead, you can make small adjustments as needed, running the fan at low or medium speed when you’re home alone and turning it up a notch when you have a large party of guests in the house.
Tight, moisture-prone homes will get plenty of use out of a heat recovery ventilator, as the system pumps out the humid air and replaces it with fresh, dry air from outside. Depending on the weather conditions, a ventilator might replace the need for a dehumidifier.
One key disadvantage of just opening windows is that you might let pollen, dust or other allergens into the house, which is particularly problematic for residents with respiratory illnesses. Fortunately, a ventilator contains filters that remove those harmful particles from the air before it enters your home, giving you all the benefits of fresh air with none of the drawbacks.
Types of Heat Recovery Ventilators
Because every home’s ventilation needs are unique, we offer a broad range of different shapes and sizes to meet those individual needs. Heat recovery ventilators can be standalone systems, or they can be incorporated into your existing HVAC equipment such as air conditioner, furnace or heat pump. If you have a small home in which nearly every room has an exterior wall, a system of small ventilators can take care of all your heat recovery and ventilation needs. For larger buildings, we often recommend investing in a single central unit.
Frequently Asked Questions
Do I need a heat recovery ventilator? Strictly speaking, no, you don’t need heat recovery to live comfortably. Every home, however, needs ventilation of some kind, and just letting inside and outside air mix has several disadvantages. Heat recovery allows you to get the benefits of ventilation without any of the drawbacks, such as increased strain on your heating and cooling systems and increased exposure to allergens.
How should I maintain my ventilation system? As with any other forced-air system, the key to maintaining a ventilator is to take care of its air filter. Depending on the model, you may need to replace a disposable filter or periodically clean a reusable filter; if it’s the latter, allow it to air dry completely before you put it back in the unit. In either case, you’ll need to replace or clean the filter every one to three months. We also recommend occasionally cleaning the energy recovery core, the condensate drain and the outside hoods and screens.
How do I choose the right system? Heat recovery ventilators are given two key performance ratings. The airflow capacity, given in cubic feet per minute (CFM), tells you how much ventilation the unit can provide. The energy recovery efficiency, given as a percentage, indicates how much heat is recovered from the air before it leaves your home. It’s also worthwhile to look at the noise level and to compare warranties before choosing a system.
Are there extra features available? Yes! The HVAC industry has put a lot of effort into making heat recovery ventilators that suit the needs of many different homes. Some systems offer moisture as well as heat transfer, which can help to control humidity. A defrost or preheater system to make sure the unit doesn’t freeze over is standard on many models. Finally, for those who suffer from allergies, models are available with high efficiency filters for the incoming air.
Where should I go to get a heat recovery ventilator? In order to make sure you get the right system for your home, you’ll need to go to an experienced HVAC contractor specializing in indoor air quality products and energy efficiency. Only a professional with extensive experience in the industry can guarantee that you get the best possible return on your investment in a heat recovery ventilator.
At Griffith Energy Services, we’ve been in the air conditioning business for nearly as long as air conditioning has existed, and we’re proud to offer energy recovery ventilators among our range of heating, air conditioning and indoor air quality products. We know ventilators inside and out, and we’ll work with you to pick out a great system that will keep the air in your home fresh and clean for many years are come. Give us a call for more information on heat recovery and other tips to lower energy bills and live that much more comfortably.
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Written by Kevin Spain