Water Source Heat Pump Design Guide
Water Source Heat Pumps are more functional in colder climates due to 
heating being a larger priority than cooling. The ground water remains at a relatively constant temperature. Depending on latitude, ground temperatures range from 45°F (7°C) to 75°F (21°C). Like a cave, this ground temperature is warmer than the air above during the winter and cooler than the air in the summer. The Water Source Heat Pump takes advantage of this by exchanging heat with the earth through a ground heat exchanger. This allows the system to reach fairly high efficiencies (300%-600%) on the coldest of winter nights compared to (175%-250%) for air-source heat pumps on cool days.
In warmer climates the same principals apply however the storing of solar energy in ponds and in the earth makes it much more difficult to disperse the heat from your house. Water Source heat pumps are being use and function well in warmer climates, but you need to have larger sources of water to drawn and disperse heat energy.
You will be money ahead by upgrading to the higher efficiency rating that applies to your climate. They are rate by HSPF and SEER.
Heating efficiency is measured by its (HSPF) “Heating Seasonal Performance Factor”. If you live in a cooler climate, this is the efficiency measurement you want to pay attention.
If you live in a warmer climate, you want to pay close attention the cooling efficiency rating know as (SEER) “Seasonal Energy Efficiency Rating”.
Water Source Heat Pumps are based on the second law of thermodynamics. The coefficient of performance (COP) plays an important role in creating heat pumps. It is the amount of heat given out, divided by the electricity that is used. Heat pumps are based on the principle of vapor compression or absorption.
A water source heat pump can also provide hot water using a device called a desuperheater” that transfers excess heat from the heat pump’s compressor to a hot water tank. In the summer, hot water is provided free and in the winter, water heating costs are cut approximately in half.
Although residential Water Source heat pumps are generally more expensive to install than air-source heat pumps they can have a 2 to 5 year pay back. Unlike air-source heat pumps, they can operate without a energy guzzling backup heat source. You can do your part by reducing energy consumption and emissions of carbon and other air pollutants.
