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). 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 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?
Hot Water Boiler Reset Control
We are looking at replacing our boiler with a new boiler. The HVAC contractor, I suppose he is the salesman for the HVAC contractor, is trying 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. Keep up the good work.
Electronic Ignition vs Standing Pilot – Modern gas furnaces use electronic ignition systems to light the burners in modern furnaces. One can still purchase a gas furnace or water heater with the old standing pilot ignition systems which have been proven reliable and safe over time but why would someone want to purchase a gas furnace or water with a standing pilot ignition system rather than purchase a gas furnace or water heater with an electronic ignition system? Let’s define the two different types of gas furnace or water heater ignition systems and then we will surmise based on that why someone would purchase a standing pilot gas ignition system over an electronic ignition system.
Residential and Light Commercial Low Pressure Steam Boilers
The residential steam boiler is still alive and well despite the fact that some HVAC professionals refer to it and the steam boiler profession as the dead mans club. However, there are not a lot of HVAC boiler technicians or HVAC companies that specialize in steam boilers because there are not a lot of the steam boilers used for residential and light commercial applications. People have either converted their old boiler steam systems over to hot water or have gone with forced air systems. The concept is simple but the mechanics of it can be frustratingly complex when a problem occurs unless you have the experience and knowledge that comes with working on the residential or light commercial steam boilers. Before we dive into some of the problems that arise with steam boilers, we’ll cover safety first. After all, HVAC safety is the most important aspect to any home heating system.
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Automatic Vent Damper System | Gas Heat Flue Economizer
The gas flue economizer or automatic vent damper closes off the top of this water heater after the burner finishes the heating process. The automatic flue damper traps heat in the furnace, boiler, or water heater and holds it in and around heat exchanger instead of allowing it to rise up the flue. The automatic vent damper is powered by the control voltage for the boiler. After the burners turn off and the noxious gases have been safely vented the automatic vent damper or gas flue economizer has a little motor that powers it to the closed position. All the heat is trapped inside the furnace, boiler, or hot water heater. Before this system came into to use all the heat around the exchanger or hot water tank was allowed to rise into the flue and vent to the atmosphere.
With the automatic vent damper or gas flue economizer the heat remains inside the unit and this adds efficiency to the system by preventing the heat from escaping into the atmosphere. To prevent the burners from lighting when the damper is closed an end switch opens the circuit to the gas valve and ignition control (depending on the manufacturers specifications). If the burners were allowed to ignite with the automatic flue damper or gas flue economizer in the closed position then dangerous noxious combustion fumes would build up in the area where the furnace, boiler, or hot water is located and cause dangerous conditions for the occupants.
Automatic Vent Damper System | Gas Heat Flue Economizer
Furthermore, the flames wouldn’t burn correctly because the combustion gases wouldn’t have a direct place to vent. If your furnace, boiler, or water is equipped with an automatic vent damper or gas flue economizer and it will not light a check of the automatic vent damper or gas flue economizer is warranted to make sure it is opening. A properly working automatic vent damper or gas flue economizer can save you in energy costs.
Air Management in Hydronic Piping Loops
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 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. (more…)
Hot Water Unit Heater Protecting a Mechanical Room
Unit heaters are used in various places to protect equipment and provide comfort to occupants. This hot water unit heater provides protection for a mechanical room where there is a large air handler and other associated equipment in the mechanical room. This system is controlled by DDC. A thermostat on the wall detects the temperature of the mechanical room. The DDC system will maintain a temperature set point by energizing the hot water unit heater fan and modulating the hot water valve open on the hot water piping. The actuator and hot water valve can be seen in this photo on the right lower half of the system. The valve is a two position valve so it is either open or closed with no modulating the valve on the unit heater. Other unit heaters for heating mechanical rooms or providing comfort include electric units heater when hot water is unavailable, gas fired unit heaters when gas (either propane or natural gas) is available, and infrared heaters typically found in large garages or warehouses for basic comfort of workers in those spaces. There are also steam unit heaters that utilize steam and a steam coil for heating spaces where steam is available. Most unit heaters are forced air unit
All About Hot Water Heaters | Water Heaters with Tanks and Tankless Water Heaters
Tankless Water Heater
I have been transformed into a believer of tankless water heater systems. Anyone who has read the About Us page at High Performance HVAC along with my friends and family and some fans of the site know that I moved to Ukraine about a year ago for professional reasons. When I first arrived in Ukraine it took a while for me to adapt to the culture, language, services, and way they do things here. Power failures, water outages, and occasionally the natural gas outages are quite frequent here although it is tolerable and a minor inconvenience. Many of the outages occur at night when many people are sleeping but occasionally during the day when you need it. I must include that this has been a big adventure and I have learned much and to tell you if you are living in the States or Western Europe you have it good but that doesn’t mean Ukraine is bad it just means they are little behind and hopefully will quickly catch up. I have not seen a standard water heater here like the common water heaters with tanks in the States. All the systems I have seen here are tankless including the water heaters in the apartment I rented and now in the house where I live. I am sure there are tank-type water heaters here like in the States but I have not seen them yet.
Boiler Components and Controls – Hot Water Boiler Expansion Tanks
Boiler Components and Controls – 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.