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…)
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.
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. These systems have been proven reliable and safe over time. However, 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. Then we will surmise based on that why someone would purchase a standing pilot gas ignition system over an electronic ignition system.
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 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 and type of venting systems 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 in the IFGC offers detailed requirements for installation of venting systems.
Never sacrifice on 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
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 man’s 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. (more…)
Automatic Vent Damper System | Gas Heat Flue Economizer. The automatic vent damper adds efficiency to water heaters and furnaces. The automatic flue damper traps heat in the furnace, boiler, or water heater. It holds heat in and around the heat exchanger instead of allowing it to rise up the flue. Control voltage from the appliance powers the automatic vent damper. The automatic vent damper has a little motor that powers it to the closed position. It leaves all the heat trapped inside the furnace, boiler, or hot water heater. Prior to the existence of automatic vent dampers, the heat escaped up the flue and vented to the atmosphere. (more…)
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. This caused those pumps to cavitate. The secondary pumps, pictured here, did not have that problem. Kudos to the team that purged the loops on this side of the chilled water system.
That was an initial installation issue. It was also a lesson in priming the system to ensure all the air purged from the loop. After all, cavitation in the pumps can cause damage to the pumps. Even after the initial installation purge, it is important to ensure air does not build up in the water piping loop. To do this we need a few devices to help purge the air before it becomes a problem. This will prevent nuisance problems such as hydronic air block in branch circuits of the loop. It will also prevent and damage that may be caused by pump cavitation as a result of too much air in the system.
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
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 a 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 - Controls - All hot water boilers must have an expansion tank. Water expands when it is heated. There must be a place for it to expand to so that the pressure in the boiler loop remains constant. Without a hot water boiler expansion tank the pressures in the boiler loop system would vary wildly. Most likely, the pressure will exceed the maximum pressures designed for the boiler hot water loop system. This will result in setting off the pressure relief valve. (more…)