Heat Sources in a Hydronics System

There are many different options when it comes to Heat Sources in a Hydronics System. Since we live in Canada I will forgo discussing heat sources that would not produce enough heat for our climate and mention only the major, well established sources.

Cost of energy compared to Electricity in Toronto April 28 2018

Electricity in Vancouver  costs only 30% of that in rural Ontario. With that in mind this chart changes considerably in BC. Also just because something runs on Electricity it doesn’t mean it is “green” if the electricity is generated in coal fired plants.

Cost of energy per season.

During the heating season, the average home uses between 50 & 150 million BTU of energy. Using realistic efficiency and net BTU figures with current pricing of available fuels, the chart below shows what one could expect to pay to heat a typical home assuming consumption of 100,000,000 BTU’s using fuel prices in April of 2018

* For this to be true the unconditioned temperature where the heat pump is located must be between 4.5C and 32C. Not a typical Canadian winter.

Pros and Cons of different heat sources

Electric Boilers/Tankless Heaters 

 Pros:

• Can be 100% energy efficient like the Thermo 200 Mini Ultra Electric Boiler
• Requires no venting so will fit in small hidden places
• Compact size
• Stage modulation meaning they use only as much energy as needed to bring the water to the set temperature.
• Simple way to supplement  your existing geothermal. heat pump, biomass or solar heating system.
• Zero emission, environmentally friendly if the electricity used is generated by hydroelectric, wind or solar generators.

Cons:

• Can cost more than a similar output Natural Gas Boiler depending on features
• Energy costs for electricity are much higher than all the other sources.

Electric Water Heater Tanks

 Pros:

• 90+% Efficient
• Requires no venting
• Zero emission, environmentally friendly if the electricity used is generated by hydroelectric, wind or solar generators.

Cons:

• Energy costs for electricity are much higher than all the other sources.

Heat Pumps

 Pros:

• Higher efficiency than Electric Water Heater Tanks
• Purchase & installation w/ incentives can be less than cost of standard tank installation
• Digital controls let you set operation of the heater according to your preference of efficiency vs. quick recovery

Cons:

• For most efficient operation, most heat pump water heaters are suited for a year-round temperature range of 40 – 90 degrees F. In Canada they must be supplemented to be able to satisfy water heating demand so they almost never work for heating as designed.
• Energy costs for electricity are much higher than all the other sources.
• Most units are large, requiring possible plumbing and installation modifications.
• About as loud as a dishwasher and may not be ideal when installed next to a bedroom or other living space.
• Has to be in unconditioned space.
• Heat pump water heaters require the air filter to be changed every 1-2 years.

Using Oil

Oil Fired Boilers

 Pros:

• Safer to store than propane
• Higher BTU/Liter than Propane
• Can be up to 86.9% Efficient like the Wiessman Vitorond 1000

Cons:

• Expensive fuel.
• Environmentally not so friendly the way it is produced to the moment it is burnt.

Using Natural Gas or Propane

Gas Boilers

Gas boilers will burn either Natural Gas or Propane. Natural gas is much cheaper and the go to source of energy. Propane is much higher in BTU but pricier  storing and delivery. Makes sense if there is no Natural Gas available (boonies).

Pros:

• Up to 98% Efficient.
• Large number of vendors and models to chose from.
• Uses a less pricey energy source (Natural Gas) while Propane is pricier but not as much as Oil or Electricity
• Straight forward installation and fuel delivery
• Versatile (on demand domestic hot water heat exchanger option in certain models)

Cons:

• Needs venting for exhausts and intake.
• Releases  CO² into the environment (so do you)
• Can blow your house up and/or release poisonous flue gases if installed incorrectly (Don’t do it yourself)

Gas Water Heater Tanks

Pros:

• Large number of vendors and models to chose from.
• Can be a lot less pricey than boilers
• Uses a less pricey energy source (Natural Gas) while Propane is pricier but not as much as Oil or Electricity
• Straight forward installation and fuel delivery
• Versatile (internal heat exchanger option for hydronic heating in certain models)

Cons:

• Lower (53-70%) efficiency than Gas boilers
• By new code cannot be installed in new construction as does not meet energy efficiency requirements. Retrofits are OK
• Keeps water at the set temperature whether you need it at that moment or not and so consumes more gas than on demand boilers
• Releases  CO² into the environment (so do you)
• Can blow your house up and/or release poisonous flue gases if installed incorrectly (Don’t do it yourself)

Burning wood (pellets or logs)

Wood burning boilers (pressurized)

Pros:

• One of the cheapest source of energy
• Carbon neutral
• Can be run on wood pellets which allows for automatic feeding
• High energy concentration
• Can be used with hydronic floor heating systems.
• Can be installed inside the house in the furnace room
• Highly automated combustion controls resulting in high efficiency and safe operation

Cons:

• Expensive boilers
• Without a pellet feeder it is labor intensive to feed
• Takes a lot of space to store the fuel
• Manual ash cleaning
• Can release poisonous flue gases if installed incorrectly (Don’t do it yourself)

Outdoor Wood Furnace

Pros:

• One of the cheapest source of energy
• Carbon neutral
• Less costly hardware
• Can be run on wood pellets which allows for automatic feeding

Cons:

• Must be outside of the house
• The large amount of water in the jacket can freeze if not heated for an extended period
• To use with hydronic radiant heating systems needs a heat exchanger and more complex hardware
• Takes a lot of space to store the fuel
• Without a pellet feeder it is labor intensive to feed
• Manual ash cleaning
• Can release poisonous flue gases if installed incorrectly (Don’t do it yourself)

Burning Coal

Indoor Coal Burning Furnace

Pros:

• Affordable hardware
• Can directly heat radiant floor heating systems
• Uses the cheapest fuel
• Can have automatic hoppers and feeders

Cons:

• The large amount of water in the jacket can freeze if not heated for an extended period
• Dirty fuel, dirty exhaust
• High level pollutants in the exhaust including heavy metals
• Can induce conniption fits in environmentalist neighbors
• Manual ash cleaning
• Can release poisonous flue gases if installed and run incorrectly (Don’t do it yourself)

Outdoor Coal Burning Furnaces

Pros:

• Affordable hardware
• Uses the cheapest fuel
• Can have automatic hoppers and feeders

Cons:

• Must be outside of the house
• The large amount of water in the jacket can freeze if not heated for an extended period
• To use with hydronic radiant heating systems needs a heat exchanger and more complex hardware
• Dirty fuel, dirty exhaust
• High level pollutants in the exhaust including heavy metals
• Can induce conniption fits in environmentalist neighbors
• Manual ash cleaning
• Can release poisonous flue gases if installed and run incorrectly (Don’t do it yourself)