Systems Comparison
RV Comparisons

Diesel Fired Hydronic Heat – How does it Compare? 
Rixen’s Enterprises, Inc. offers a complete hydronic heating and hot water system. This system can 
heat your coach and your hot water too! But what is a hydronic system? And 
how does it compare to other types of systems? The basics of each system 
are outlined below.

THE HYDRONIC SYSTEM

The circulation of hot water to provide heat is known as a “Hydronic” System. It is a closed system, meaning that it continually circulates the same coolant. It begins with the furnace, usually fueled by diesel, or electric elements that heat the coolant to 180 degrees. A system pump circulates the hot coolant through a domestic water heater and then to the various fan units located throughout the coach for interior heating. An engine coolant loop can be added to preheat the engine. The following features are based on Rixen’s Enterprise's Quantum Heating System.

 

Hydronic System Features

Constant output of heat no matter what the weather or temperature

The water to air transfer does not remove the moisture from the air

Heats domestic water on demand

Transfer of heat from water to air is more efficient

Domestic water output - 106 degree F continuous @ 2.7 GPM

Ύ” water lines are easier to route and maintain heat better

Several fan units allow multiple heating zones

Closed coolant loop requires less maintenance

Self-diagnostic main control board – owner serviceable

High/low 120V AC settings enable you to control power consumption

Engine waste heat loop - included

Utilizes 12Vdc or 24Vdc power

Engine pre-heat loop - optional

Low amp draw fans offer quiet operation

Air Conditioning and Reverse Cycle Heat

An air conditioning system is made up of several components and uses a refrigerant to transfer the heat. The evaporator converts the liquid into a vapor as it absorbs heat. The high pressure and heated vapor then travels to the condenser where it releases the heat and is cooled. It now returns to a liquid state and travels to the compressor to repeat the cycle until enough heat has been removed from the space. An air conditioner typically lowers the air temperature 15 to 20 degrees F. The reversal of the process can create a limited amount of heat as it is subject to the outside air temperature.

AC / Reverse Cycle Heat compared to Hydronic
• The cooler it gets the less heat it can produce
• Can not heat the domestic water supply
• Can not use engine waste heat
• Can not pre-heat the engine
• Can not pre-heat the engine
• Requires a 120V AC power source, you must use shore power or a generator

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Propane Forced Air

This system burns propane (LP gas) to create heat. Air is drawn into the furnace where it is heated to nearly 200 degrees F. This heat is forced through the ducting or outlets and into the space by means of a high output air fan. The air ducting is usually a minimum of 4” in diameter. The ducting can be flexible duct hose or a hard ducting similar to a house. The furnace s are available in 12V DC or 120V AC models.

Propane Forced Air Heat compared to Hydronic
• Air temperature is lost through the ducting
• Large fan is used to move heat through the whole system
• High temperature causes large temperature swings and bakes the moisture out of the air.
• The loss of moisture can dry out the skin and nasal passages.
• BTU capacity of LP gas decreases with the outside temperature. This means if you are low on fuel your furnace may not work.
• Qualified service technicians are recommended
• LP gas leaks can create dangerous situations
• LP gas does not burn as clean as diesel fuel
• Can not use engine waste heat
• Can not pre-heat the engine

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  Propane/Electric Water Heater

This system heats the domestic water supply in your coach. They typically hold 6 or 10 gallons of water. The water is heated with a propane fueled burner and may be supplemented with a 120V AC electric element. Some units offer an engine exchange loop to transfer engine waste heat while traveling.

Propane/Electric Water Heater compared to Hydronic
• Excessive weight – A 10-gallon unit weighs over one hundred pounds
• Poor recovery rates – First hour @ 28.8 gallons with a 60 degree temperature rise
• Qualified service technicians are recommended
• BTU capacity of LP gas decreases with the outside temperature
• LP gas does not burn as clean as diesel fuel
• LP gas leaks create dangerous situations
• Can not pre-heat the engine

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