Heat recovery systems are a popular, energy saving technology being installed in buildings all across the country. But while it is fast growing in popularity, there are still many who know nothing about it, even if it could result in significant energy savings and better, cleaner air. So, what is heat recovery exactly, and why should you consider it for your home? Let’s take a deeper look at the technology behind it, what it does, and a few rare cases when this technology might not be the best suited for your home.
Heat recovery systems are designed to capture the heat from air that is being expelled from your home to heat the fresh air coming into it. The reverse is true in the summer. The air coming into your home is cooled by the air exiting your home. This reduces the amount of energy required to heat or cool your home during both seasons.
A heat recovery system doesn’t involve fancy equipment, and it doesn’t require you to replace your existing heating system. Instead, it can work within your ventilation system. In each room of your house, there are ventilation ducts that bring fresh air in and take stuffy air out. These ducts connect to the heat exchanger that exchanges heat between the incoming and outgoing air before the outgoing air is vented into the atmosphere. The heat exchanger simply exchanges heat so that the incoming air is almost at the same temperature as the outgoing air.
The outgoing and incoming air will not mix with each other. This means that you don’t have to choose between energy efficiency and feeling stuffy. Instead, stale air is pushed outside while up to 90 percent of the heat in it is transferred to the incoming air.
One of the biggest benefits of MVHR, or mechanical ventilation with heat recovery, is that it provides a steady stream of filtered fresh air to your home without wasting the energy used to heat or cool it. Home heat recovery systems can exchange the air in your home every two hours or so. Trickle vents may exchange less than one percent of your home’s air per hour. The end result is that you get fresher air and less allergens floating into the house.
An MVHR system can be great for clearing dander, chemical residues, and dust out of the air in your home. And you won’t end up bringing in pollen and pollutants like you would if you just opened a window. The constant stream of air also keeps the air vents in your home clean. Cobwebs and mold can’t grow inside your air vents. Any bad odors or chemical sprays are quickly eliminated as well.
This is especially important when considering the recent “sick house syndrome” epidemic we’re seeing all over the country. Sick house or building syndrome is when inhabitants start experiencing health issues because of some underlying condition with the house, such as mold for instance. Not only does MVHR technology prevent mold from forming, but it clear spores from the air as well.
Another point in favor of heat recovery systems is that it is a green technology. You aren’t wasting warm stale air by venting it outside when you bring in fresh air. That heat is recovered as you bring in fresh air. You won’t work the boiler or heater as hard keeping your home warm in the winter, though an MVHR system won’t eliminate the need for them altogether. And you can save even more energy with these systems, because you can control the air exchange rate. Lower the air exchange rate, and you may not have to run the radiators very long at night.
In larger buildings, an MVHR system will help you keep the temperature in the entire building at the same comfortable temperature. It pulls heat from hot rooms like kitchens or wet rooms and distributes it evenly across the building, and it eliminates the cold spots that arise in inefficient systems where those downstream receive little heat. This reduces the temptation for employees to open the window to let in fresh air or turn on small heaters to get warm.
Another benefit of heat recovery systems is that they move the large volume of air and exchange the heat without the noisy mechanical fans that are otherwise required. This may make your home or workplace much quieter.
Condensation prevention is reason enough for homeowners to consider buying one. The average family exhales fifteen liters of moisture into the air as they breathe, cook, shower and do laundry. In the typical home, most of that moisture remains trapped inside the home. This can foster mold growth, and lead to peeling wallpaper and condensation pooling where it can cause structural damage. A heat recovery system’s steady stream of fresh air eliminates this excess moisture. You can use the heat exchanger as a dehumidifier in the winter too.
A heat recovery system is ideal when the building is fully insulated and all the little places where warm air can escape are sealed. If you’re in an older leaky home, you probably shouldn’t get a heat recovery system until the home is better sealed. If the doors and windows of your building are always open, an MVHR system may not be a good idea. A heat recovery system is a logical choice for newer, eco-friendly buildings.
In large industrial buildings, a heat recovery system may already be fitted into the condensing boiler. Older boilers probably have a flue economizer but may benefit from being fitted with a heat recovery system.
Heat recovery systems correct the poor indoor air quality that has resulted from the tightly insulated and poorly ventilated homes we’ve built. They’re also a great way to reduce your carbon footprint, energy consumption, and cut on costs. If you feel like a heat recovery system could be a good option, we suggest you speak with a professional so that you know which options are open to you.