What is the difference between direct and indirect fired water heaters?
Direct fired water heaters are solely dedicated to the job of hot water generation, providing a faster heat up and response time compared with an indirect system which is in fact ‘heating water to heat water’. This increases the chance of heat losses in the boiler,...
What is the difference between direct heat and indirect heat when grilling?
There’s a big difference between direct heat and indirect heat when you’re grilling, and knowing when to use each can really affect how your food turns out. In a nutshell, direct heat means cooking your food directly over your source of heat, while indirect heat means cooking food adjacent to your heat source.
What is the difference between direct heat transfer and indirect heat transfer?
The main difference between direct and indirect heat transfer systems is the expenditure of air required to achieve heat transfer. Chilling, heating, processing and cleaning air results in high energy consumptions in direct heating processes. While no air is required in indirect heat exchangers, reducing energy costs and allowing for ...
What is indirect heat technology?
INDIRECT HEATING TECHNOLOGY. Indirect heat transfer results in a higher quality final product, as the bulk solid does not come in direct contact with air or fluid, eliminating the risk of contamination. The slow, controlled downward flow through the indirect heat exchanger plates also prevents abrasion and degradation to the material,...
What is direct heating and indirect heating?
In a nutshell, direct heat means cooking your food directly over your source of heat, while indirect heat means cooking food adjacent to your heat source. This photo is an example of direct heat, since the lobster is being cooked directly over burning coals.
What is the difference between direct and indirect water heating methods?
A direct-fired water heater heats up with propane, oil, or natural gas and has its own burner. Indirect water heaters use a boiler or furnace to supply the heat needed for the water.
What is better direct or indirect water heater?
Benefits of separating the heating and hot water systems Direct fired water heaters are solely dedicated to the job of hot water generation, providing a faster heat up and response time compared with an indirect system which is in fact 'heating water to heat water'.
What is the difference between direct and indirect central heating?
Direct and Indirect A 'direct' cylinder is heated via an electric immersion and does not work with gas, oil or heat pump systems. An 'indirect' cylinder has coil running through the cylinder. 'Primary' heating water (not fresh water) passes through the coil and is heated by the boiler to around 70 degrees C.
Is indirect water heater worth it?
An indirect water heater, if used with a high-efficiency boiler and well-insulated tank, can be the least expensive means of providing hot water, particularly if the heat source boiler is set to "cold start." Indirect water heaters are a more efficient choice for most homes, even though they require a storage tank.
Do indirect water heaters need to be flushed?
Indirect vs Tankless The most obvious difference between an indirect and tankless heater is the existence of a tank. Indirect water heaters have a limited hot water supply and require flushing, two issues a tankless heater is less prone to.
What is the most efficient hot water heating system?
Uses renewable energy: Solar water heaters are the most energy-efficient water heater options available today.
What is the most efficient way to heat hot water?
Put simply, heating your water via your central heating gas boiler is your cheapest and most efficient option, if you have it.
Are indirect water heaters more expensive?
Higher Installation Costs: Often, indirect water heaters are more expensive to install than many traditional water heaters.
Do I need a direct or indirect cylinder?
In fact, in simple terms : You need a DIRECT hot water cylinder if you want the cylinder to heat the water itself, and… You need an INDIRECT hot water cylinder if you have a separate boiler (such as a gas boiler or an oil boiler) and will be using that to heat the water.
What is direct heating system?
In direct heating systems, heat is generated directly within a material by passing electric current through it, or by causing controlled exothermic reactions, or by exciting atoms or molecules inside the material by electromagnetic radiation (e.g., microwaves).
What are the advantages of indirect hot water system?
The greatest advantages of the indirect water heaters are the significant reduction of flue losses. Less maintenance – no additional burners to maintain. Less cost – no additional venting required or fuel lines to run. Better performance – more available hot water with quicker recoveries.
How do I know if my hot water cylinder is direct or indirect?
1:566:55DIRECT & INDIRECT HOT WATER CYLINDERS - Plumbing tipsYouTubeStart of suggested clipEnd of suggested clipNow that is the main things that differentiates. It from a direct cylinder. The water comes up fromMoreNow that is the main things that differentiates. It from a direct cylinder. The water comes up from the boiler. Through our control valve according to the thermostat.
What is direct heating?
Direct heating can fundamentally be defined as the control of thermal energy absorbed or rejected through manipulation of exogenous factors. In other words, it involves placing an SMP into a hot environment.
What is a direct hot water system?
A direct fired hot water system is fed via a direct fired water heater where the heat source for the water is physically located within the unit. This heater, such as an integral gas or oil burner, heats the water directly.
What are the advantages of direct system of hot water supply compared with indirect system?
Energy is saved as pumps are not required to pump water to cistern/tanks. Installation cost is reduced compared to indirect water supply because no storage tank is required and even reduces maintenance cost of tank (underground as well as overhead). It reduces the chances of bacterial contamination.
How much energy is needed for direct contact heat transfer?
In direct contact heat transfer systems large amounts of air are required for the process to achieve sufficient heating, cooling or drying. This requirement results in the need for air handling systems, large fans, extensive ducting and emission stacks. Pre-heating the air, as well as processing and cleaning the air, requires high energy consumption. Rotary drums and fluid beds can consume over 600kW of energy for a direct heating application of 100 tph to achieve a 25°C temperature change. While these direct heat transfer systems have been in place for decades, they are proving to be an inefficient use of resources, with a high energy consumption.
How does a bulk solid heat exchanger work?
Direct bulk solid heat exchangers utilize vertical, enclosed hopper bins or silos that allow for the injection of gas, commonly air, to directly heat or cool the free flowing material passing through the equipment. The gas and bulk solid (ex. powder) are both fed into the heat exchanger in two streams, at different temperatures. The gas can either flow counter-current to the bulk solid, fed from the bottom upwards, as the material flows down or cross-current, in a perpendicular fashion across the material as it flows down. For successful operation, adequate heat transfer, uniform flow, proper outlet size, reliable gas flow and sufficient unit volume are required. Unlike rotary drums or fluid beds, bulk solid direct heat exchangers have no moving parts, lowering installation and maintenance costs.
What is the difference between direct and indirect heat transfer?
The main difference between direct and indirect heat transfer systems is the expenditure of air required to achieve heat transfer. Chilling, heating, processing and cleaning air results in high energy consumptions in direct heating processes. While no air is required in indirect heat exchangers, reducing energy costs and allowing for ...
How does a fluid bed work?
This technology works well when a precise control of temperature and residence time is required such as in polymer, chemical and pharmaceutical industries. Fluid beds force air through perforated steel beds that fluidizes free flowing bulk solids. As material is added to one end of the fluidized bed, it moves gradually from one end of the bed to the other. Air or gases are introduced in this process, moving between the material particles, removing the moisture and changing the final temperature. Air has two functions in fluid bed technology; first it creates the fluidized state of the material enabling the product to flow and second, it either heats or dries the material through direct contact.
What is direct heating?
Quite simply, direct heating technology involves a bulk solid material coming into direct contact with a heating gas to change the final temperature of the material. On the other hand, indirect heating technology does not allow the product to come in contact with air or gas or any other heating agent to change the final temperature.
Why is indirect heat transfer important?
There are numerous advantages to using indirect heat transfer systems: Increased energy efficiency, as there is no need to use air in this process, eliminating redundant equipment. This process uses up to 90% less energy than traditional technologies.
How do rotary drums work?
Rotary drums are commonly used to remove moisture content from a free flowing bulk solid, by bringing the material in direct contact with a heated gas, commonly air. A rotary drum is a cylindrical tube, that slopes slightly downwards and rotates rapidly. As the product (ex. powder, fertilizer, sugar) enters the drum dryer, the rotating mechanism lifts the material up onto a series of internal fins lining the inner walls of the dryer. As the material flows toward the discharge end, it falls off the fins and passes through the hot gas stream within the rotary drum, removing moisture. The gas flowing through the drum can flow in either a co-current or counter-current direction.
What is direct heating?
Direct heating above the use of some type of book material that will come into direct contact with a heating gas. Basically, it directly transfers the heat from the internal burner to the general airflow. These units will usually convert about all of its fuel into heat.
Do all furnaces use indirect heat?
And general, all home furnaces rely on indirect heating. These units rely on an enclosed heating cheaper to heat up the room. Cool air is passed over this heat exchanger and will become more and more hot. Indirect heating sources tend to be a bit more expensive to operate. They are also a little bit less efficient. However, they are ideal for tightly sealed, indoor spaces.
How does carbon monoxide kill?
Carbon monoxide poisoning kills workers every year. Victims are usually using fuel-burning equipment in spaces without adequate ventilation , according to the Occupational Safety and Health Administration. Indirect fired heaters do not produce carbon monoxide, carbon dioxide or nitrogen dioxide, so they are safe to use in tight spaces, although they still need an exhaust outlet. In addition, since the air is emissions free, operators can use duct systems to transfer warm air from an indirect fired unit to other nearby spaces.
What is indirect fired heater?
Indirect fired heaters deliver cleaner air with less humidity. Excess humidity can create drying and curing problems during some operations and lead to mold development in extreme cases. Indirect fired heaters can actually help some wintertime processes, like the curing of concrete, along.
How does a fire heater work?
Fired heaters do just as the name implies: generate heat via the use of combustible materials. In direct fired heaters , air is forced across an open flame. In an indirect fired heater the flame is contained in a special burner, which warms up a heat exchanger. Air is then forced across that exchanger to heat up the area.
Can you use an indirect fire heater in a tight space?
Indirect fired heaters do not produce carbon monoxide, carbon dioxide or nitrogen dioxide, so they are safe to use in tight spaces , although they still need an exhaust outlet. In addition, since the air is emissions free, operators can use duct systems to transfer warm air from an indirect fired unit to other nearby spaces.
Who is Kim Slowey?
Kim Slowey is a writer who has been active in the construction industry for 25 years and is licensed as a certified general contractor in Florida. She received her BA in Mass Communications/Journalism from the University of South Florida and has experience in both commercial and residential construction.
Is a direct fired heater more efficient?
Direct fired heaters may be more fuel efficient overall , but since indirect fired heaters do not have the fresh air requirements of direct fired heaters, they can save fuel when used in recirculation mode or to warm nearby spaces.
Do direct fired heaters require electricity?
Some models of direct fired heaters are less expensive than their indirect counterparts and don’t require electricity, but since direct heat over an open flame can add carbon monoxide to the air, their use is limited typically to larger, well-ventilated spaces like warehouses or open construction areas. Deciding whether to use an indirect fired ...
Why are direct fired heaters used?
Since direct fired heaters have an exposed flame similar to a stovetop or grill, these units should be reserved for areas where there is plenty of ventilation and less foot traffic. Direct fired heaters are ideal because they are cost-effective, efficient, and easy to transport. Common applications include:
What is indirect heating?
Indirect Fired Heaters. Indirect fired heaters are just like your home oil or gas burning furnace with a chimney. With propane or natural gas heating units, the flame is contained in a burn chamber which heats a “heat exchanger”. The cooler air passes over and around the heat exchanger, thus heating the air.
What is priority rental?
At Priority Rental, we offer a broad variety of direct and indirect fired heaters for rent or purchase. For a more general overview of the heaters we offer, visit our portable heaters page.
What is direct fired gas?
With propane or natural gas heating, units force air directly through the flame to heat the air.
What are the positives of indirect heating?
Indirect fired heaters offer some positive points, like: 100% clean, dry air – The air being circulated never comes in direct contact with the flame. Built-in thermostats – Almost all indirect fired heaters use a thermostat. Can operate in tightly sealed spaces – Indirect fired heaters do not release carbon dioxide into the space.
What is a built in thermostat?
Built-in thermostat – On most models, a thermostat is used to control the temperature
Can indirect fired heaters release carbon dioxide?
Can operate in tightly sealed spaces – Indirect fired heaters do not release carbon dioxide into the space.
Why do you use ductwork for a heater?
The heater re-circulates air, which saves fuel. You may use ductwork to deliver hot air into different areas of a project site without the risk of fuel-hazardous byproducts, such as carbon dioxide. Because the heaters don’t release harmful gases, you can use them in tightly sealed spaces.
How efficient are direct fired heaters?
Advantages. Direct-fired heaters use 100 percent of the combustion gases to heat air, making them more efficient than indirect-fired heaters. Some heaters can operate in areas with temperatures as low as -30°F. You may use ducts to carry hot air throughout a site or facility without worrying about fumes or exhaust.
What is indirect heating?
Indirect-fired heaters are similar to oil- or gas-burning furnaces with chimneys in homes. In such units, a flame in a burn chamber warms the heat exchanger. The device draws cool air into two different chambers. The air passes over and around the heat exchanger and gets warm. The air that the heater discharges is clean, making this type of heater good for applications that require sanitary conditions, such as health care facilities, food processing plants and areas with chemically sensitive products.
Why are direct fired heaters not appropriate for use in tightly sealed spaces or near flammable materials?
Disadvantages. Direct-fired heaters are not appropriate for use in tightly sealed spaces or near flammable materials because of the exhaust and fumes produced. The heated space must have some type of air exchange or an exterior window or door that you can open. The warm air produced is not always dry.
What are the disadvantages of indirect heating?
Disadvantages. Indirect-fired heat involves multiple working parts, making it less efficient than direct-fired heaters. Rental prices tend to be more expensive compared to direct-fired heater rental costs. Indirect-fired heaters use about 80 percent of the combustion gases to heat air. The heaters are larger than direct-fired heaters, ...
How much gas does an indirect heater use?
Indirect-fired heaters use about 80 percent of the combustion gases to heat air.
What is direct fire heater?
Direct-fired heaters are similar to barbeque grills or gas stovetops, as they heat the air that passes through an open flame. Internal components within the heater control the warmed air, making it an efficient heating solution.
What happens when you cook steaks on a ceramic burner?
In this photo, two steaks are being seared over intense direct heat on a ceramic searing side burner. When searing a steak, the intense direct heat will cause the surface of the cut to form a delightful brown crust that helps to keep juices locked in and contained within the meat.
What to cook on a grill with indirect heat?
Or dishes that require more time to cook at low temperatures, like roasts, ribs, and briskets. Just be careful opening your grill with indirect heat. When you open the lid, all that heat escapes, and it takes a moment for the firebox to come back up to temperature.
What does it mean when avocados are off the grill?
The burner beneath the avocados is off, which means they’re taking in heat from the hot air and smoke around them (not necessarily from the grates). With indirect heat, heat transfers to your food not from the grates beneath it, but from all the hot air circulating through the firebox.
What does it mean to set up a heat zone on a grill?
When you hear recipes talk about setting up “heat zones” on the grill, it usually means to set up half your grill for direct heat, and half for indirect heat. These different zones give you more command over your heat transfer.
What is direct heat grilling?
In a nutshell, direct heat means cooking your food directly over your source of heat, while indirect heat means cooking food adjacent to your heat source. This photo is an example of direct heat, since the lobster is being cooked directly over burning coals. Translated to the grill: When you place foods on ...
Can you cook steak on the inside or outside?
But just because it’s seared on the outside, doesn’t mean it’s cooked perfectly on the inside. That’s where you might move the steak over indirect heat. Indirect heat will be less intense, which is great for bringing your steaks up to the perfect temperature depending on your choice of doneness.
Is indirect heat the same as direct heat?
It’s a process known as convection heat, and it’s pretty dang similar to the way your oven works. Since indirect heat isn’t normally as intense as direct heat , it’s a good way to go for foods that are a little more delicate–like whole chickens and oily fishes.
What is the difference between direct and indirect plumbing?
The difference between direct and indirect plumbing systems concerns how cold water is distributed throughout the home. In an indirect system, the cold taps are supplied by the cold water storage cistern in the loft. In a direct system, they’re supplied by the mains.
What are the advantages and disadvantages of an indirect water system?
Advantages and disadvantages. The main advantage of an indirect system is that even if the water supply to the property is cut off, there’s still a reserve of water. For example, you’ll still be able to flush the toilet until the loft cistern is empty. Indirect systems also operate at a lower pressure than mains water.
What is a cold water storage cistern?
The cold cistern supplies cold water to everywhere else in the household, such as the cold bathroom taps, and the hot water cylinder. In a direct system, all of the cold outlets are supplied by the mains. The cold water storage cistern supplies only the hot water cylinder.
Why is it not recommended to drink from a bathroom tap?
This is historically the reason why drinking from the bathroom taps in British homes is not recommended. In contrast, direct systems offer drinking water from every cold tap in the home. Their other main advantage is that their higher pressure means much greater flow rates.
What is direct and indirect water?
In this context, direct and indirect refers not to how the cylinder is supplied, but how the water is heated. For more information, check the hot water cylinder page.
Do you need a water tank in a loft?
Indirect systems obviously require space in the loft for a bulky water tank. Long, narrow “coffin” tanks are available, but in the case of a future loft conversion, a complete change of plumbing system may be necessary, for example, removing the cisterns in the loft and converting to a combi boiler system.
Do hot water cylinders need a cold water storage cistern?
In a direct system, all of the cold outlets are supplied by the mains. The cold water storage cistern supplies only the hot water cylinder. Alternatively, there may not even be a storage cistern if the property has a combi boiler or an unvented hot water cylinder. Both of these appliances are fed directly from the mains.
What is indirect fired?
Indirect fired units such as calorifiers have no integral burner but contain one or more heat exchanger coils that are filled with hot liquids (water or solar fluid) that have already been heated ‘indirectly’ by one or more external heat sources, such as a boiler or solar collectors.
Why are water heaters installed close to point of use?
Water heaters are often installed close to point of use, reducing the energy required to supply water over a long pipe run and minimising distribution heat losses.
What is direct fired water heater?
Direct fired water heaters are solely dedicated to the job of hot water generation , providing a faster heat up and response time compared with an indirect system which is in fact ‘heating water to heat water’. This increases the chance of heat losses in the boiler, and associated pipework between the boiler and calorifier.
What temperature does an indirect fired boiler operate at?
However, an indirect fired system will generally operate at 80/60, temperatures at which a boiler cannot condense consequently not actually operating at part load (which requires a return temperature of 30°C).
How does a Dorchester water heater work?
Direct fired units such as Dorchester water heaters for hot water generation have an integral gas or oil burner that directly heats the water in its storage cylinder by supplying hot gases through one or more of its heat exchanger fire tubes within the cylinder which then transfers heat to the surrounding water.
What is the efficiency of a boiler?
When producing hot water with return boiler temperatures likely to be 60°C or higher, the boiler is more likely to be operating at a gross efficiency in the region of 88% .
Can an indirect fired boiler be used for both the heating circuit and the DHW system?
Historically, indirect fired systems would have a dedicated hot water boiler for heating a calorifier but with modern highly efficient boilers, the same boiler can now be used for both the heating circuit and the DHW system.
What Is An Indirect Water Heater?
This water heating system uses a tank to store water and an external heat source to warm it up. Indirect models do not have any heating elements inside the water tank. Instead, they will use the home’s space heating system (a furnace or boiler) to heat the water. Utilizing the space heating system for your water is called an integrated or combination heating system – as the two different units work together.
What is the difference between a tankless and indirect water heater?
The clear difference between these two systems is that indirect heaters use a water storage tank, while tankless heaters have no tank at all. This means that indirect units are limited in the amount of hot water that they can produce, while tankless heaters can produce an unlimited supply.
What is indirect heating?
When combined with the fact that there are no heating elements being used in the tank, indirect heating systems can be the most energy-efficient solutions available. Indirect water heaters can be powered by electricity, solar energy, gas, propane, oil, or a combination.
Why is indirect water heating better than conventional water heating?
When using an indirect water heating system, you can save a great deal of energy. Thanks to the system vastly reducing the amount of standby heat that is lost , an indirect heater proves to be far more efficient. This is also seen in the reduced running of the boiler or furnace.
How much hot water can a tankless heater provide?
An important thing to note is that tankless heaters can only supply a certain amount of gallons per minute. Indirect heaters can provide as much hot water per minute as you like – as long as it fits within the tank’s holding capacity.
How does a water storage tank work?
Uses a water storage tank without heating elements. The water is heated through a heat transfer coil system. This is connected between the storage tank and a boiler or furnace. The tank stores energy, reducing the number of times that the boiler/furnace turns on. Indirect models can be incredibly energy efficient.
What is the name of the system that heats water?
Instead, they will use the home’s space heating system (a furnace or boiler) to heat the water. Utilizing the space heating system for your water is called an integrated or combination heating system – as the two different units work together.
