Not sure which type of heating system you have? Not sure which system you want to install? We thought it would be beneficial to go back to the basics, ensuring we have a strong foundation of HVAC knowledge before we move on to bigger things.
But before we get into those, it’s important to note that you must first determine a type of fuel or energy you want to use, or due to geographical restrictions, that you may or may not have access to. Natural Gas (NG) is the most popular and the cheapest here on the west coast. Now up somewhere near the midwest, fuel oil is more commonly use due to the fact that NG is hard to come by around there. So each situation might have different circumstances, so just be sure to start with this topic. There’s also electricity, which powers most of the electric space heaters, and electric resistive heating (not allowed as primary source in California anymore). Electricity is much more expensive to buy, due to the fact that it’s hard to produce and store for extended periods of time.
Picture Source: http://www.vaibhavraikhare.com
Here we tell a brief overview of the types of building heating systems that occur in the U.S. and what the benefits are. We focused mainly on industrial/commercial applications, although some of the smaller systems can be utilized as a home owner/residential applications as well:
Furnaces – These units are very efficient, usually around 78-96% efficient and typically driven off of Natural Gas, Propane, Oil or wood. The idea here is to ignite a pilot light (now offering electric ignition or wood) provided by the fuel supply, and blow that hot air around the room using a small fan inside the furnace (some don’t come with a fan – they use natural radiant heat instead to heat the room). This is effective for smaller systems, but when systems get large and complex, an integrated boiler is usually the better option.
Boilers – Typically natural gas (NG) or propane fired, these boilers use fuel to burn and heat water indirectly, or directly (Primary and secondary systems), and supply hot water to the HVAC terminal boxes (at the space you want to heat) or at the Air Handling Unit (AHU) where air is blown over the HW coil to heat the air downstream in the duct. New boilers are very advanced, with smart controls features and efficiencies over 80%.
A primary/secondary setup, is when your primary loop is a closed loop through the boiler, in which has its own recirculation pump, a heat exchanger which transfers heat from primary loop to secondary loop, and the secondary loop heats the space using its own HW recirculation pump.
These are helpful because boilers have a minimum flow regulation on them or else they can crack or burn out easily. So having a separate pump to satisfy the boiler, and a separate pump to satisfy the space, is a much more effective way of delivering your heat.
Heat Pumps – Think of this unit as a reverse refrigeration cycle. Instead of removing heat from a space using refrigerant, the evaporator becomes a condenser and the condenser becomes and evaporator, pouring hot air into a space. These systems work very well, and can be added to a packaged air handling unit during the time of purchase. Not all manufacturers supply their units with heat pumps, so be sure the ask for this specifically if that’s how you plan to heat the space.
Picture Source: https://en.wikipedia.org/wiki/Air_handler
One of the main benefits of a heat pump system, is they are extremely efficient, often comparable to that of the gas furnace and electric resistive heating. You have geothermal heat pumps, which uses the ground as a heat source during the winter (and opposite for the summer). You can recirculate air or water through deep wells into the ground, which use convective heat transfer to heat your space.
You can also incorporate a smaller “mini-split” system incorporated with heat pumping capabilities. These are basically tiny wall mounted HVAC units, with the evaporator inside the space and condenser outside (for heat pump this would be opposite, condenser inside and evaporator outside). These are very effective, inexpensive and easy to install on retrofit jobs.
Picture Source: http://lakewayair.com/mini-splits/
Electric Space Heaters – These are generally frowned upon as they consume a TON of energy to operate. Electric resistive heating sends a current from your wall socket (AC power) and sends it through a giant wire, and the longer the wire, the more losses occur across that wire, giving off heat. This heat is then blown into the space by use of a fan. The reason people use these is because they’re relatively cheap considering no renovation is required, and they can be purchased at any local hardware/tool store (home depot, etc.).
A few other types of residential heating sources are:
Wood-Burning and Pellet Stoves
Fireplaces
Gas-Fired Space Heaters
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