IERNA's Heating & Cooling Blog : Posts Tagged ‘Clearwater’

HVAC Question: What is a Heat Pump Reversing Valve?

Monday, July 23rd, 2012

Did you know that heat pumps can be used for both heating and cooling in your Tampa home? The reversing valve is what makes this possible, read on to learn more!

In General

Functioning on the same principle as refrigerators, the heat pump uses a liquid to absorb heat as it turns into a gas and release heat as it returns to a liquid state. During the summer, the heat pump operates as a standard central air conditioner, removing heat from the house and venting it to the outside.

In the winter, the heat pump reverses this process, extracting heat from the cold air outside and releasing it inside the house. The heat pump is very efficient when the outside temperature is around 45 degrees Fahrenheit to 50 degrees Fahrenheit, but it becomes less efficient as the temperature drops.

The Heart of the Matter

The reversing valve in the heat pump switches the process from absorbing heat from the inside to evacuate outdoors like an air conditioner to extracting heat from cold temperatures outside and redistributing it indoors.  The thermal energy at play is the natural force of heat to move toward cooler temperatures, releasing energy in the shift.  Heat pumps take care of both and the reversing valve controls the direction of the flow.

The reversing valve has two states of operation: relaxed and energized.  In the relaxed state, the heat pump can be programmed to introduce either heated or cooled temperatures into the conditioned space, depending on the direction of the flow of refrigerant through the closed loop.

By applying a 24 volt charge of AC current (a low voltage typically used in HVAC systems), the valve becomes energized and reverses the flow, producing the opposite conditioning.  The reversing valve may be driven by the heat pump through the use of a control board or directly by a thermostat.

Will a Heat Pump Work in My Home?

To determine if a heat pump is right for the heating and cooling of your Tampa home, call Ierna’s Heating & Cooling. We will determine the needs of your home and which Tampa HVAC system will work best for you and your family!

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AC Guide: Components of An Air Conditioning System

Monday, April 30th, 2012

Our Tampa air conditioning system is a modern convenience that we can easily take for granted as long as all the parts are working well.  In every unit, no matter the size, the basic process is one of extracting heat from the conditioned space and moving it to the outside, leaving cool air in its place.

This process easily divides into indoor and outdoor components.

Air Conditioning 101

Based on the principal of thermal energy which states that heat gravitates toward cooler temperatures, compounds known as refrigerants are moved through a closed loop system, repeatedly contracting and expanding between liquid and gas forms, alternately releasing and absorbing heat along the way.  The particular chemicals are selected for their abilities to transform from one state to the other at low temperatures.

While the refrigerant evaporates into a gaseous state within the looped system, it absorbs heat, removing the stale air from the space being conditioned and evacuating it to the outdoors. The warm air is pulled through ducts to meet with the cooling loop.

Ductwork

The cooled air is distributed through ducts or tubing and released into individual spaces.  Additional ductwork is required to remove the stale air and pull it back to be reconditioned as it passes over the loop containing the refrigerant.  The air is moved in both directions by a blower, usually electric and sized to handle the amount of air no matter the building.

Ductwork is also sized to handle appropriate volumes of air. To maintain efficiency, large trunks distribute along central lines to smaller ones reaching farther out. The return air is usually taken from common areas.

The grates are found in the walls, floors and often as part of the dropped ceiling. When combined with a forced air heating system, the total energy use is much more efficient.

Looped Coils

The refrigerant is enclosed in a loop where it can expand and contract to make its transformation from gas to liquid and back again.  To change into a heat-absorbing gas, it travels through the evaporating coils, an intricate series of delicate fins that meets with the ductwork to regenerate the conditioned air.

An exchange valve allows just the right amount of liquid refrigerant into the evaporator coils.  If there is too much, the tube is flooded too tightly to allow expansion of the molecules and room to attract the heat.  If too little, the process is inefficient.

AC Maintenance

When set up and maintained on a regular basis, the system functions with little attention and over sight.  To set up a maintenance appointment for your Tampa air conditioning system, give Ierna’s Heating & Cooling a call!

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