Boiler Types - There are many different types of boilers in the boiler room today in a variety of heating applications. There are two main categories of boilers among the different boilers and those two categories are steam boilers and hot water boilers. Either of those categories can be fueled by oil, gas, or electric (although electric is uncommon for steam boilers). (more…)
Boiler Efficiency Options - High Performance HVAC wants to help you understand your next boiler purchase better. To do this we want to break down all the different types of boilers and components, and various options and features that you may find when making a purchase.
Typically, you want to find a like replacement for the boiler you currently have installed, or if you are buying a new boiler, you want a system that will handle the load and is durable. The most important feature of the new purchase is usually the fuel efficiency simply because the cost of running the new system will give you pay back over time for the new purchase.
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Hot Water Boiler Reset Control - Richard, We are looking at replacing our boiler with a new hot water boiler. The HVAC contractor, I suppose he is the salesman for the HVAC contractor, is trying to sell us what he refers to as a reset control for our boiler. He tells us it will save us more money by making our boiler more efficient. I think I understand how it works but my wife is not entirely sure about it. Can you tell us what you think about a boiler reset control and how it works?
Thanks, and we have learned so much from High Performance HVAC. And keep up the good work.
Brent (more…)
Boiler Stainless Steel Exhaust Flue Stack: This is a photo of a boiler stainless steel exhaust stack. It is used for venting corrosive boiler combustion gases. As the flue gases leave the boiler they cool and depending on the dew point of the gas, the gas will experience a change of state. It will change from a gas to a liquid. This liquid is highly corrosive and only special flues like stainless steel vent can be used when this occurs. Stainless steel prevents premature failure of the boiler vent.
There are many considerations to consider with a new installation of a heating system in comparison to the type of vent to be utilized. The venting system used to vent the gases from the boiler or furnace safely outdoors. It is imperative that safety guidelines be followed when installing any type of venting system for furnaces or boilers using fossil fuels. For detailed information concerning code requirements for installation of venting systems see the IFGC or International Fuel Gas Code. Chapter 5 and Appendix C of the IFGC offer detailed requirements for the installation of venting systems.
Never sacrifice safely, consult a professional when in doubt. There are many rules to follow. A professional will know these rules and apply them as they install the system. They will also, have the system inspected by the code official in your area to double-check to ensure safety guidelines were followed
Boiler Circulator Pump: The boiler circulator pump induces the flow of hot water through the boiler and the boiler loop. Usually, the boiler circulator pump is controlled by the aquastat. However, there are various levels of control that can be found that control pumps.
One way is by the aquastat as mentioned above. Another way is an end switch in a zone valve. A thermostat in a particular zone will call for heat and the thermostat calls for the zone valve to open.
When the zone valve is fully open, an end switch closes the circuit to energize the circulator pump. Typically, the circuit is a control circuit so when the end switch closes it closes the circuit for a relay to energize the circulator pump (more…)
The air handler coils should be checked for dirt and debris which may have been sucked into the air handler inadvertently. Some air handlers have filters inside them before the coils. It is a good time to change the filters when making this check.
Any dirt or debris on the coil(s) should be removed immediately as these things will impede airflow through the air handler and throughout the entire system as a whole. Dirty evaporator coils can cause AC problems. Some air handler coils are installed in the air handler cabinet while other coils are installed in the ductwork. (more…)
Commercial Boiler Stack Economizer - This is not a normal commercial boiler stack in this boiler room. It has a bypass stack for a commercial hot water economizer. All boilers have make-up water to make up for water lost in the systems, especially for domestic hot water use.
An economizer makes things more efficient. In this regard, the economizer utilizes waste heat. Waste heat is normally vented into the atmosphere. This system was specially engineered and tested to ensure the proper operation of the design. (more…)
Old Bell Gossett Circulator Pump Bearing Assembly - This very old Bell Gossett Circulator pump and bearing assembly was found still functioning even after being flooded out several times in a basement. The pump, probably on its last leg, is at least 20 years old and still functioning.
It is unusual for an electric motor to continue to operate after being subjected to flooding. A circulator pump is comprised of an electric motor and a bearing assembly which holds the impeller. (more…)
Aquastat is the gray box on the left while the circulator is the black pump on the right.
Aquastat Temperature Control - The boiler aquastat controls the temperature of the water inside the boiler jacket. The boiler aquastat is a device to a boiler like a thermostat is to an air conditioner, heat pump, or gas/oil furnace. A boiler aquastat controls the temperature inside the boiler just as the thermostat controls the temperature for an air conditioner or heat pump.
The boiler aquastat will turn the burners on and off and also controls the circulator pump on a hot water boiler system.
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HVAC Near Boiler Piping Components - HVAC near boiler piping is very important to a good hot boiler loop circulation of the water. Hot water loop piping is key to maintaining good water flow throughout the system. The placement of valves, the circulator pump, and other loop controls are generally installed near the boiler. (more…)
