Choosing A Heat Pump For Your Home
In practical terms, a heat pump is basically an air conditioning unit that can both cool and heat a house. This works through the magic of thermal transfer: a heat pump can extract heat found in the ground or air outside of your home and move that heat into your home. In ideal circumstances, a heat pump will be much more energy efficient than a coal or gas furnace.
Is a heat pump the best choice for my home?
Despite their appealing ability to both heat and cool a house, heat pumps are not necessarily the best choice for every home. There are several factors to consider before purchasing a heat pump.
Seasonal temperature variation in your area is one of the most important things to consider. If the temperature rarely drops below 40 degrees Fahrenheit, you can probably heat your pump year round with a heat pump more affordably than you could with a furnace. If you live in a cooler area, you should consider having a backup heat source. An oil or gas furnace can pair well with a heat pump for this purpose. This is termed a dual fuel system, and can offer great cost-saving benefits: by running your heat pump during parts of spring and fall that aren’t as cold, you can only run your furnace in the cold of winter, cutting back on your natural gas usage.
You may also want to consider the relative costs of electricity and natural gas or oil. Historically, electricity has been more expensive, but as petroleum costs have skyrocketed over the last decade, this is no longer the case in many areas. When you use a heat pump, you will save money relative to a gas furnace when electricity costs are cheaper than buying natural gas. It’s thus important to research energy costs in your region before making a purchasing decision.
What size of heat pump should I buy?
Choosing a heat pump with the correct output for your home size is crucial in keeping your home comfortable while reducing energy bills. For maximum efficiency, heat pumps need to be sized to run continuously. A heat pump that is too large will cycle on and off too frequently, which decreases its efficiency and makes it wear out much more quickly. A heat pump that is too small may not be able to keep you warm in the winter and cool in summer.
Unfortunately, there is no shortcut way to determine the heat pump size your home needs. You will need to hire an HVAC contractor to calculate your house’s heating load. This is a somewhat complicated calculation that takes into account your house’s size, insulation, amount of shade, and other important factors. Don’t skimp on this step, since proper sizing of the heat pump is the single most important factor in determining its efficiency.
Understanding heat pump efficiency ratings
The cooling and heating functions of heat pumps have their own separate ratings that measure efficiency. A heat pump’s heating efficiency is measured by its Heating Seasonal Performance Factor, or HSPF, while its cooling efficiency is measured by its Seasonal Energy Efficiency Rating, or SEER.
Both these ratings are important, but your priorities will vary with your climate. In a warmer climate, you will need more cool and less hot air, meaning that you will want to choose a heat pump with a high SEER. In a cooler climate like Longview, WA, you will want a heat pump that can warm your house as efficiently as possible, so you should choose a heat pump with a high HSPF.
Very efficient heat pumps generally cost more upfront than less efficient models. However, this additional upfront investment can save you money in the long run. You can calculate how long it will take to pay off the increased cost in savings on your energy bill. An upgrade can be especially worthwhile if you are planning to stay in your house for several years, since you will save money every month. A lower heating bill isn’t the only benefit: higher efficiency models will reduce your house’s impact on the environment as well.