Cleaner and Greener: Heating and Cooling with Heat Pumps

Heat Pumps are a new use for an old technology: refrigeration.  The new use is home heating.  The same process used for cooling your fridge is used at a larger scale for heating or cooling your home. It gets hot behind a refrigerator because heat is moved outside from inside.   If a home has central air conditioning now, the heat pump may use the same ducts and power source.  

The advantages of heat pumps are less energy is used to heat a home and cleaner electricity is used instead of gas or oil.  So heat pumps save homeowners money over time.  

What is a Heat Pump?  It is an air conditioning system that can ‘pump’ or move heat in two directions: From inside the home to outside in the cooling season, and from outside the home to inside in the heating season.  The innovation of recent years is that these systems can now work effectively with outside winter temperatures as low as 15 degrees.  

Outside: Condenser

Inside: “Mini-split”

…or Through Ducts

How are they more efficient?  A brand-new gas condensing boiler with state-of-the-art controls can never produce more heat energy than the heat content of the gas that is burned.  96% input-output efficiency is tops.  But a heat pump is a machine: it uses electrical energy to compress refrigerant, which takes heat from one side of the home’s walls to the other side.  Efficiency on-site can be 300% to 500% of the electrical energy used.  Electrical generation is becoming more and more climate-friendly due to cheap solar and wind power.

Do Heat Pumps work as air conditioners too?  Yes, a reversing valve, costing about $15 to make, allows the heat pump system to change from heating in the winter to cooling in the summer.  Heat flows the opposite direction, but the air handlers and fans push out conditioned air – warmer or cooler.  

Is this better for the environment?  Yes, because gas or oil alone is not being used for home heating and the ‘clean mix’ of renewables in the electricity supply will increase over time, so electric power becomes greener.  

Are they expensive?  If you are about to replace or upgrade your heating or air conditioning system, they are almost the same price -  or they could be cheaper.  A tax credit is available from the IRS of 30% of the cost of the heat pump, capped at $2,000.  If you have systems that might fail in the next year or two, “early” is the perfect time to shop, particularly between the air conditioning and heating seasons.  

How should I determine if a heat pump system is a good replacement for my air conditioning and heating systems?  That is for the next article in the CNEP newsletter where we will cover which equipment qualifies for the tax credit, where to look for other incentives,  what to look for in an HVAC contractor,  and how to plan for what to do if it gets bitterly cold below what your particular heat pump can handle.

References:  

IRS page on Tax Credits for Heat Pumps:  https://www.irs.gov/credits-deductions/home-energy-tax-credits