Tag Archives: electric heat

Duct Work and High Ceilings | HVAC Duct Work Systems

Duct Work and High CeilingsDuct Work and High Ceilings - I did not see any reference to my question and would appreciate a response as soon as possible, as due to medical situation, have to make a decision soon. We own an OLD house with 13' ceilings in a large part of the home and 11" ceilings in the LV/DR and BR. We are oscillating on where to place the ducts....Floor or ceiling. It appears to be counterproductive to me to put the duct work in the ceiling since it will have so far to go. We are looking for the most cost effective, not upfront cost but operating cost, solution. In addition, we are considering DF heat pumps. The house will need 2 or 3 to be zoned correctly. Please let me know about the duct placement and thank you for your help?

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Variable Air Volume Box with Hot Water Reheat | Commercial HVAC

Variable Air Volume Box with Hot Water ReheatVariable Air Volume Box with Hot Water Reheat - The variable air volume box or VAV box is a commercial solution to adding multiple zones to large buildings. VAV boxes offer zoning solutions so that separate zoning demands or temperature selections can be maintained in different areas of the building. If the president of the company wants the temperature in their office to be 70 degrees Fahrenheit but the vice president wants their office to be 74 degrees Fahrenheit then it is possible with the VAV zoning system as long as their VAV boxes are on different zones.

Variable Air Volume Box with Hot Water Reheat

  This particular VAV box in the picture is not fan powered. It relies on the main VAV air handling unit to provide all the air. Generally, when a fan powered VAV box is calling for heat the damper inside the VAV box closes down so that minimal CFM’s are coming through the primary duct from the air handler. The fan turns on an pulls air from the plenum space above the ceiling. This plenum air is normally warmer than the air inside the occupied space. The heating system kicks in and adds heat to the air until a setpoint is attained. The heat for a VAV box can typically be a hot water coil or electric heat strips. The VAV box in the picture has hot water reheat.

High Performance HVAC

Variable Air Volume Box with Hot Water Reheat

 

   

Hot Water Unit Heater Protecting a Mechanical Room

Hot Water Unit Heater Protecting a Mechanical RoomUnit heaters are used in various places to protect equipment and provide comfort to occupants. This hot water unit heater provides protection for a mechanical room where there is a large air handler and other associated equipment in the mechanical room. This hot water unit is controlled by DDC. A thermostat on the wall detects the temperature of the mechanical room. The DDC system will maintain a temperature set point by energizing the hot water unit heater fan and modulating the hot water valve open on the hot water piping. The actuator and hot water valve can be seen in this photo on the right lower half of the hot water unit heater. The valve is a two position valve so it is either open or closed with no modulating the valve on the unit heater. Other unit heaters for heating mechanical rooms or providing comfort include electric units heater when hot water is unavailable, gas fired unit heaters when gas (either propaneor natural gas) is available, and infrared unit heaters typically found in large garages or warehouses for basic comfort of workers in those spaces. There are also steam unit heaters that utilize steam and a steam coil for heating spaces where steam is available. Most unit heaters are forced air unit

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Air Handler Components 2

Air Handling Unit Components: Air Handling Unit Heat There are many different types and arrangements of heating systems for air handling units and these types of heating systems and arrangements of heating systems vary from commercial to residential. Some air handling units do not have any heat source inside them at all but have remote heat for zoning. The air handling unit provides the air flow and the remote heaters provide heat for zoning. Sometimes the air handling unit is a VAV air handling unit and other times it is just to provide air for a duct heater whether the duct heater is gas fired or electric. For air handling units which some have heating systems inside the five main ways of providing heat for air handling units are:
  • Electric Heat Strips
  • Gas Heat
  • Oil Heat
  • Hot Water Coil Heat
  • Heat Pump (Process of Refrigeration Heating)

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Air Conditioning and Heating: Heat/Energy Values

Air Conditioning and Heating: Heat/Energy ValuesHeat is energy and when we produce heat we need to use energy in its production. There are natural methods for producing heat without burning or using fuels but these methods are not practical or available to the general populace for residential, commercial, and industrial use. The production heat, whether for residential, commercial, or industrial uses, uses energy and energy costs money. It is thereby necessary to have reliable and proven methods of measuring the amount of heat produced using a specific quantity of energy. Employing these reliable and proven methods we can also use the data to determine the best methods of producing heat for homes, businesses, and industry.

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FRIDAY, APRIL 18, 2014

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