SAVING ENERGY BY DOWNSIZING AND USING A HEAT RECOVERY VENTILATION SYSTEM

In the year 2020 we are trying to build a house for sustainable living. Taking into account the fact that energy prices will be higher our task is to build an energy efficient home with a financial limit of $300,000. There are three scientists on each team. On our team: the engineer Dr Abdul Daman, the environmental scientist, Dr. Kendra Acre and myself the physicist Dr Luna Spacey. We will be talking to you amount two methods we used in our house design to reduce energy use: downsizing to a smaller house and the heat recovery ventilation system.

During our research we got the idea to downsize our house from an experiment we did. It showed that the amount of heat energy needed to heat a substance to a particular temperature depends on the mass of the substance. We realized that the amount of heat energy needed to bring the air in a house to a particular temperature depends on the mass of air contained in the house. In other words, the bigger the house the more energy needed to heat or cool it.

Our house for a three person family has just 648 square feet of space to be heated in winter or cooled in summer. It is cozy and comfortable. Our house is a single story home which makes it easier to maintain a balanced temperature. We have additional unheated space that includes a garage, porch and patio. During the summer the family have more space to use. We believe that downsizing is the single most important thing we can do to reduce energy use for heating or cooling a house. Reducing energy use would reduce greenhouse gas emissions and help stop global warming.

The second method we would like to describe is the heat recovery ventilation system. Ventilation is important for your home. It is a way to keep your house safe from dangerous chemicals like carbon monoxide, or toxins from smokers, gas leaks or just household products like hairspray. In modern homes the architectural structure and design is so airtight that even small amounts of chemicals can have a large impact. In winter normal ventilation systems extract hot air from the house and bring in cold fresh air.

The heat recovery ventilation system heats the cold fresh air using heat energy from the warm outgoing air. To do this it uses a heat exchange system of aluminum passage ways that are in close contact with each other. When the air in the warm passage ways touches the walls it transfers heat through the aluminum from the hot to the cold passage ways. The heat recovery ventilation system can result in up to 85% of heat staying in the house while allowing appropriate ventilation.

In winter in Canada the HRV must have a defrost damper. With a defrost damper if the HRV gets frost inside, the damper shuts down the HRV for a few minutes while the ice melts, then the HRV starts running again. This keeps the HRV in good condition. The HRV system is generally placed in the basement or attic and is connected to the supply air-return vents in the house’s main ducting.

The unit costs between $700-2000 depending on the size of the house. We highly recommend the heat recovery ventilation system to city council. It is a simple relatively inexpensive method to reduce energy use for heating buildings. Using HRVs would cut down on greenhouse gas emissions and help stop global warming.