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 types of boilers and those two categories are steam and hot water boilers. Either of those categories can be fueled by oil, gas, or electric (although electric is uncommon for steam boilers). They have different designs and piping configurations as a steam boiler system is designed to turned the water into steam and uses gravity and pressure to deliver the heat and the hot water boiler systems are designed to simply make hot water to be circulated (by a circulator or pump) through a piping system to provide heat. Typically, hot water boilers are more efficient than steam boilers for a few reasons. First, there is less heat loss throughout the hot water piping and the shell of the boiler because the hot water boiler operates at a lower temperature than the steam boiler. This means there is less heat loss throughout the entire boiler and piping system. Secondly, because the hot water boiler operates at a lower temperature, it requires less fuel or energy to convert into heat. What kind of boiler do you have in your boiler room?
This is a secondary chilled water pump in a large pump room designated for pumps and piping in a data center. After a few minor tweaks and corrections these pumps all operated flawlessly. There was very little issues with the secondary pump start-ups unlike the primary pumps where cavitation was encountered on the primary chilled water pumps and the condenser water pumps for the chiller. The diagnosis for the cavitation of the primary pumps and the condenser water pumps was that the loops were not properly purged of air and this caused those pumps to cavitate. The secondary pumps, pictured here, did not have that problem giving kudos to the team that purged the loops on this side of the chilled water system. Continue reading “Air Management in Hot and Chilled Water Piping Loops” »
There are two types of expansion tanks used on hot water boiler systems. The steel expansion tank and the bladder type expansion tank. These expansion tanks are used to provide a cushion for the expansion of water when it is heated. Without this cushion of air the pressure in the boiler system would rise and exceed the setting on the pressure relief valve causing the pressure relief valve to open and discharge water to relieve the pressure. It is necessary to for an HVAC technician to understand how these expansion tanks work in order to properly troubleshoot hot water boiler problems which may occur as a result of an issue with an expansion tank. One of the first things to check on a hot water boiler system when the pressure relief valve discharges water excessively is the expansion tank. Continue reading “Hot Water Boiler Expansion Tanks” »
Hot Water Boiler Expansion Tanks
All hot water boilers must have an expansion tank. Water expands when it is heated and there must be a place for it to expand to so that the pressure in the boiler loop system remains constant. Without an expansion tank the pressures in the boiler loop system would vary wildly and most likely will exceed the maximum pressures designed for the boiler hot water loop system. This will result in setting off the pressure relief valve. There are two different types of expansion tanks that can be used on hot water boiler systems. The most modern is the bladder type expansion tank (see picture to the right). The other type of expansion tank is a basic cylinder or barrel looking tank that hangs from the ceiling or is located in the attic. These tanks need to be drained from time to time to make sure they are not full. If they fill up with water and have to be drained constantly there is a problem with your boiler that should be looked at by a boiler technician. The bladder type expansion tank does not need draining on a regular basis like the cylinder or barrel type tank.
Hot Water Boiler Piping for a commercial boiler application. Boiler project being renovated and getting all new DDC controls for optimum hydronic control and efficiency. Boilers are an excellent way of providing good hot water heat to a large building or community. Some people refer to them as furnaces, hot water heaters, hot water heating systems, or hot water heater but the proper name is to call them hot water boilers. Hot water gas boilers provide clean draftless hot water heat through pipes and piping systems which HVAC professionals refer to as hydronic piping. Typically, hot water heating systems use pumps or circulators to move the water through the hot water piping system. Hot water heat is considered to be a good source of draftless heat by the people who have these hot water heating systems installed in their homes and businesses. Continue reading “Boiler Piping Plant Renovation” »
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. In the photo one can see the circulator pump, the expansion tank, the flue that exhausts the gases from the combustion process, an automatic air vent just to the right of the hot water loop circulator pump, a PRV or pressure reducing valve where the boiler make-up water comes into the boiler, and some unidentifiable controls. These loop components make up the near boiler piping which is very important to a good installation. If the near boiler piping is not installed properly several problems can occur that will cause issues with the heat and efficiency of the heating system as a whole.
Purchasing a boiler can be daunting for most people as many people do not understand boilers and do not know what certain components are with boiler systems. Typically they trust the installing contractor to outfit and install the boiler with all the proper boiler components including making recommendations for optional boiler components. There are resources we can use to try to understand boilers and boiler components but overall this research or study will not make one an expert in boilers and boiler installation. We simply have to trust the boiler installer and the skills of the boiler contractor.
Airtrol Valves help maintain the proper level of water inside expansion tanks. The valve allows air and water to flow into the tank where the air level in the tank allows for a cushion for expansion and contraction of the water in the loop. Since liquids do not compression air is used as the compression medium in the expansion tank to allow the loop to expand and contract without setting off pressure relief valves. The B&G Airtrol Valve is used in compression type expansion tanks without a bladder in the tank. Bladder type expansion tanks work differently than compression type expansion tanks. The B&G Airtrol valve takes the guess work out of ensuring the expansion tank has the proper level water and air inside the expansion tank.