HVAC

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If your ​current heating and cooling system is old, inefficient, expensive to run or just not doing the job, it’s time to upgrade. An electric heat pump heating system is highly efficient and can reduce energy consumption and money, as well as significantly lower your impact on the environment.

What’s your existing HVAC ​​system? 

There are many kinds of heating and cooling systems you can use in your house. Depending on the heating source and appliances, it can be grouped into three major categories as follows:

a. A natural gas furnace and a central air conditioner: It is the most common HVAC system in Ann Arbor. 

b. Dual-fuel: It is a combination of an electric heat pump and a gas furnace. The heat pump replaces the central air conditioner and provides cooling in the summer. It also could heat the house in the winter and use the natural gas furnace as a backup heating source for the consistent heating capacity on extremely cold winter days.

c. All-electric: It uses electric resistance to heat the house. Depending on the type of appliances, it includes in-floor radiant, electric resistance, and ​electric space heater. About 22% of households in Ann Arbor use electric resistance for heating. It uses a lot of electricity and can significantly increase energy bills. 

d. Other: It includes traditional boilers and radiator systems. These systems use a central boiler that circulates steam or water through pipes to radiator units around the house. It could use natural gas, propane, fuel oil, and biodiesel blends.

W​hat are the options of an HVAC system that​ reduce carbon footprint and reduce energy usage?

• Air Source Heat Pumps 

Air Source Heat Pumps (ASHPs) can either be ducted (working with an established duct system in a home) or ductless, and usually have an outdoor and an indoor component. They are easy to install and can be customized to the needs of the home. They are considerably more energy-efficient than natural gas furnaces or resistance heaters (baseboard units). 

• Ground Source Heat Pumps 

Ground Source Heat Pumps (geothermal) work in a similar way as ASHPs, but they transfer temperatures to and from the ground. They require digging deep wells for installation and can be difficult to install on small city lots. They are extremely efficient and currently qualify for a 26% federal tax credit, helping significantly reduce the cost of installation. 

• A combination of a heat pump and a gas furnace

It is a combination of an electric heat pump and a gas furnace. The heat pump replaces the central air conditioner and provides cooling in the summer. It also could heat the house in the winter and use the natural gas furnace as a backup heating source on extremely cold winter days.

​Why are heat​ pumps so energy efficient? 

A heat pump is a device that warms or cools a space by transferring thermal energy from a cooler area to a warmer one, using the refrigeration cycle to reverse the flow of air. In the summer a heat pump will pull warm air out of your home and deposit it outdoors, just as a conventional air conditioner would. In the winter, it pulls warm air from the outdoors (even when it’s very cold), compresses it to increase the temperature, and transfers that air into your home. Therefore, heat pump systems provide both heating and cooling with the same equipment. If you don’t have a cooling system now and are considering installing one, this will provide for both needs. Heat pump systems have advanced in recent years and are extremely efficient, even in cold climates. 

Why should I co​nsider switching to a heat pump or replacing an AC with a heat pump?

Most homes in the Midwest are currently heated with gas. Natural gas is primarily made up of methane, which is an extremely potent Greenhouse Gas (GHG), and a significant contributor to climate change. Methane leaks occur at multiple points along the path from extraction to transmission to distribution. This includes leakage in our homes, which can contribute to poor indoor air quality and health impacts, including asthma, allergies, and learning deficiencies. By choosing an electric heat pump, you are helping to reduce methane emissions in your home and the environment. (RMI, 2019 provide source link).

​Reducing methane in our atmosphere is a powerful way for us to relatively quickly combat global warming, as methane absorbs more heat than carbon dioxide. 22% of homes in Ann Arbor currently use resistance heating (or baseboard heaters) to heat their homes, and replacement with electric heat pumps would result in energy and money savings. The installation of a heat pump would replace AC window units needed in these homes as well, resulting in a more comfortable home year-round. 

If you natural gas furnace is relatively new and your AC is at the end of its life, replacing the AC with a heat pump would be an option to consider as well.  A heat pump can serve as an AC to cool your home in summer and heat your home on​ cold days. Your existing natural gas furnace can be backup heat when the outdoor temperature is freezing.

​Can a Heat Pump Han​​dle Ann Arbor's Cold Climate?

Proven technical advances have greatly improved heat pump performance in cold climates; cold climate heat pump models maintain efficiency down to 5 deg F, and some are even capable of performing below -10 deg F. These heat pumps have been successfully field-tested in climates like Minnesota and the Arctic Circle. Integration with backup electric resistance systems provides an extra layer of security during rare, too cold of days. 

The heat pumps of today are capable of far more than those from previous decades. In response to concerns about cold climate performance, cold-climate-specific standards are being rapidly developed to provide real-world performance information in cold climates. Both the Northeast Energy Efficiency Partnership and the Canadian Standards Association are working on these standards. 

​Tips to save energy​ and improve indoor comfort

• Following a regular maintenance schedule can reduce your heating and cooling costs by 5 -10% and prolong the life of the equipment. 

• Invest in preventative checkups. Hire a professional HVAC technician to inspect systems for proper functioning. Air conditioners should be inspected in the spring and furnaces should be checked in the fall, before use. 

• Consult the owner’s manual. Your owner’s manual should provide details on system maintenance and upkeep. Clean or replace filters monthly during seasons of peak use. 

• Cleaning and replacing filters will reduce heating and cooling bills while also extending the life of the equipment. Seal duct leaks. 

• Sealing ducts with fiberglass mesh and mastic can control humidity and dust. Many HVAC service companies will do this at a reasonable price. Keep the area clean around outdoor air conditioners and heat pumps. Clear away weeds and debris so that air can circulate freely around the unit. 

• Check for disconnected or crushed duct work. Improperly connected or crushed duct work can restrict flow so that warmed or cooled air never reaches its intended destination.

For more information on HVAC system, please refer to the DOE’s Guide to Home Heating and Cooling. 

Workshops and e​vents

Sticker Campaign

Committing to replacing your current gas appliance with an electric heat pump option when the time comes? Join our sticker campaign. Take the A2ZERO Pledge, and indicate you would like to switch from a gas appliance to an electric one.

Heat pump workshops

Want to know more about heat pumps and find contractors? Please check out recordings of past workshops on heat pumps.  If you are interested in future workshops and events relating to HVAC and heat pumps, please email Fang Wu at [email protected]. We will send you upcoming events relating to heat pumps. 

Heat Pump Workshops (past)

You can access a recording of this workshop here.

1. In May 2021, the City held and recorded a Heat Pump Workshop discussing how heat pumps work and their many benefits: Heat Pump Workshop Recording

2. In September 2021, the Green Home Institute and OSI hosted a workshop for reside​nts to learn about heating their homes and water with cleaner electricity. Representatives from heat pump manufacturers were on hand to provide detailed information and answer questions: Heat Pump Workshop Recording