Designing your hydronic heating system to function with multiple boiler stages by switching on/off multiple smaller capacity boilers will save money, energy, limit potential wear and tear and add a higher degree of comfort to your building.
Large heating loads supplied by one or two very large boilers typically don't make sense when the heating plants full capacity may only be required for 5-15% of the entire year. A smaller boiler may keep up with the demand 50% of the time in most cases. Staging controls allow you to take full advantage of the benefits derived from a series of smaller boilers/stages cycled on as the heating load dictates. Overshoot and undershooting of desired room temperature can be reduced, while saving money.
Multiple boilers provide an inherent backup in the event of a boiler failure. Quality staging controls also allow for automatic rotation of all boilers with various options to equalize runtime. download drawings (ZIP - 186 files)
Hi-temp boiler supply water can be mixed with a lower temp distribution system. Valves or pumps can be used to temper the distribution system water temp. As part of a closed loop system the mixing valve or injection pump is designed to divert a calculated amount of hot water into the distribution system, at the same time the distribution system gives up the same amount of returning cooler water back to the boiler side to be re-heated and re-circulated. Thermistors in the boiler and distribution loops provide feedback to the Control, which regulates the distribution water temp.
Large distribution loops can return very cold temperatures back to the boiler. If unabated, this cold water creates condensation in the flue. This condensation mixed with exhaust from the combustion process creates sulphuric acid, corroding metallic components in its path. High temperatures released from the boiler may crack concrete and warp floor coverings such as hardwood. Correctly installed mixing systems compensate for this. download drawings (ZIP - 40 files)
Domestic Hot Water (DHW) Theory
Larger commercial and industrial users often choose to run independent boiler systems from the existing space heating boiler system. Several advantages support the theory of independent boiler plants/systems.
Dedicated DHW loads can be sized to optimize the efficiency with boiler selection options. Options exist to use potable water through the boiler as would apply to direct forced systems, and eliminate the potential for internal ingress of glycol through heat exchangers. DHW systems tend to exhibit both very large temperature drops and very subtle temperature drops depending on time-of-day and usage. Short cycling of boilers and pumps can be problematic which may lead to large overshoot or undershooting of target temperatures. download drawings (ZIP - 8 files)
Dual System Theory
The principle of the Dual System ID Card is to control 2 traditionally separate boiler staging applications via one controller:
- A hydronic heating system, staged on indoor/outdoor reset control.
- A dedicated and hydronically isolated domestic hot water (DHW) boiler package staged by either a DHW setpoint thermistor or an aquastat.
The heating system takes full advantage of boiler temp reset based on outdoor temp and controls the main heating/boiler system pump, as well as staging/rotating the heating boilers. DHW can be turned on independently of the heating boiler when the heating boiler is not required. Glycol and non-glycol systems can be separated and controlled in the example of direct fired systems. These 2 systems may also be monitored and controlled as one when the optional Computer Interface Software is purchased. download drawings (ZIP - 7 files)
Dual Mixing Theory
The Dual Mixing application will allow for mixing capabilities in multi-family dwelling applications (and certain industrial buildings). Two separate mixing systems (ie. In-joist heating and in-slab heating) are able to be controlled via a single HBX Control, giving each independent heating characteristics. download drawings (ZIP - 4 files)
Solar energy is the most abundant energy resource in the world. Every day, more sunlight is available than the world can use for all of its energy needs. Collecting the sun's clean energy and transforming it into practical forms of heating is the focus of the rapidly growing solar energy industry. Optimizing the control strategy in a solar system is key for achieving optimum BTU return. Whether utilizing solar panels or solar tubes, the ECO-1000 can improve tanks, pumps and panels in the system to draw maximum heat from the solar devices; thus increasing efficiency and effectiveness of your solar application.
A multiple tank feature provides you with the ability to run numerous storage tanks simultaneously, allowing for the added benefits of continuously keeping the lead tank as hot as desired. As well as a backup feature, the ECO-1000 Control has the advantage of controlling overheated occurrences by turning on a pump or valve to dump/shed excess heat from panel or tank. download drawings (ZIP - 38 files)
The earth's temperature a few meters below the ground is relatively constant everywhere in North America while the air temperature can change from summer to winter extremes. Geothermal heat pumps combined with a dedicated geothermal control (ECO-1000) can tap into this natural heat source and provide a positive energy return to your residential, commercial and industrial applications.
The HBX Control Systems ECO-1000 will allow you to take advantage of the benefits derived using outdoor reset to improve compressor efficiency. The ECO-1000 control combined with the Computer Interface Software (CIS) allow for features such as monitoring and troubleshooting parameters accessible to the installers/end-users with simple but sophisticated fine tuning characteristics. download drawings (ZIP - 28 files)