RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

I do not mean that I know enough and do not need to read more.

What I meant was not to read Wiki links, but to spend more time with the EPlus manuals.

I am still reading the EPlus manuals.

I mentioned that the example files are not as good as the old ones for a beginner, because the team wanted to cover more new features in the new examples.

Your question on SmallOffice building has been answered. There are more ref. buldings in the example files folder. The SmallOffice building in the OpenStudio is slightly different. The windows are combined into one big one. The slooped roof has a flat top.

These files are also available for many different locations in US. I looked at a few and did not find much difference in the building mterial construction and material for different states.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Fri, 17 Feb 2012 23:13:02 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Saturday, February 18, 2012 1:28 AM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

T.T

See my reply below'

Mark all the names used in the IDF on your schemetic. Every item you need are there. One part that is not shown in your schematic diagram is the coil in the DHW tank. There are others. Doing this exercise will help you to understand the process and design.

Do not worry of the the names, heater, boiler, water tank, intermediate tank, heating tank. They may be called differently in different part of your diagram.

The boiler is a furnace with a fire. The gas fire boiler object is in the hotwater plant loop.
If the furnace has a water jacket, that is part of the HW tank.. The temperature of this is monitored with a thermostat and controls the gas fire.

The HW boiler plant loop is a closed water loop. This loop feeds all the radiators and the coil in the DHW tank. This is shown correctly in your simulation. The reason why you do not see the result is simply you did not ask them to be displayed in timestep interval and the schedule values may be wrong. Do not add any more setpoint manager,etc, because you are not in the position to use them yet. EMS parts are not in your real system.

I suggest that you should identify all the names in the IDF and mark them on your schedule. Then find all the values for each representative time step at a certain ODT. (Night, morning, noon, afternoon, etc.) If you cannot find the name or values, ask again using one IDF only.

The DHW tanks has a float valve, as you turn the tap, the hot water is used, and the tank is filled from the water main at a low temperature. You never mentioned this, and I assume that you do not know how this is done. You never mention where the DHW tank is. I assume that it is at the roof top. All these details, you must find them and add them to your schematics.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Fri, 17 Feb 2012 18:47:34 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Dear Dr.Li

i read this :

A hot water heater is the storage tank of water that is responsible for the supply of hot water to the many fixtures in the house, such as showers and sinks. I know that, that is why I always refer it as the DHW tank. You do not realize the difference because you did not show the HW heating coil in the tank.

It does NOT supply heat for the home itself. There are two basic types of water heaters, one that runs on gas or some other fuel and one that runs on electric. The electric heater is probably in the DHW tank and is called the auxiliary heater in the EPlus simulation. This is not in the IDF yet. When the boiler is turned off in Summer, the DHW can be supplied using this electric heater. The rating is usually about 3Kw for a 10 gallon tank. The electric heater has its own thermostat, and will turn on and off at a lower water temperature. This may be the 65°C you were talking about.

A boiler on the other hand IS responsible for the heating of a home itself. Water or steam in a boiler reach much higher temperatures than the water in a hot water tank and therefore its used for heating and not drinking water or potable water. Portable water is never supplied from the DHW open tank.

In a steam system for heating, pipes run throughout the house from the boiler carrying steam that eventually gives off its heat at the many radiators. In a hydronic system for heat, smaller pipes carry hot water to various baseboards around the house that release the heat using circulator pumps to push the water through and back to the boiler. Are you talking your real system or another system? If the thermostat is set at 80°C it is not a steam, although they are referred to as "steam" radiators so that people would not place their hand on it. This why EPlus has a separate low temperature hydronic radiant model.

the building that i modeled : the boiler has thermometer and the heater that includ portable water doesn have thermometr it is heat exchanger that has two coil one for hot water from boiler and another for shower ,sink,... Thermometer is not thermostat.

could you please help me

thanks

I do not need to read more from Wiki. Read the EPlus manuals.

You do not have a clear picture of your system.

Boiler means it can boil water into steam. In EPlus, a boiler in a plant loop need not run at 100°C to produce steam.

Heating tank is definitely designed not to produce steam.

Heater is the heat source, which can be gas, oil, electric, etc.fired.

Immersion heater, is a heater inserted in the tank.

You can call a coil in a tank a heat exchanger. There are many other names.

Dear Dr.li i say read this i mean i read this in internet , and i m sure your are well in knowing this dear Dr.Li,

in my building there is tank with natural gas heater in tank and has thermostat in its tank that measured hot water temperature in its tank and control heater , that provide hot water to radiator , and also provide hot water to closed space like heat exchanger that there is coil,

DHW heater can be inline, open tank, storage, etc. These can simulated in EPlus and are described in the reference manual.

Read more: http://wiki.answers.com/Q/What_is_the_difference_between_a_hot_water_heater_and_a_boiler#ixzz1mfMQO7m7

From: Tooran T <t.t111ir@xxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Friday, February 17, 2012 6:59 PM
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Dr.Li now i found one thing i dont know is that correct or not

i found that what i mean from boiler is water heater You have both boiler and water heater. If you do not turn off the gas, the water will boil. The DHW tank will never boil.

in my building boiler has burner or heater and has tank and thermometer that measured the water in the tank and if its temperature is greater than 80 then boiler will be on ,..

what i mean from water heater is coil exchanger that one side is connect to hot water and another is connect to cold water from main pipe , then this two tubes exchange Q from hot water and cold water ,...

The coil of the furnace or boiler exchange heat with the DHW tank. The water main provide the water to the shower taps. It is controlled by a float valve to keep the DHW tank full.

but now i dont know from what class object i can simulate this heat exchanger ? This is already done in your IDF as two water loops. The only item need to be verified to make sure that the names of the objects are correct for the DHW system. There are examples in the examples folder. I use the one for solar collector, and for storage tanks.

thanks

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Friday, February 17, 2012 12:42 AM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

T.T

I do not know how you add the schedules, etc.

If you use a text editor, all the manager and schedules can be kept together.

After you have written the manager and the controller, you will immediately follow by the set point schedule by copying the name from the controller to the schedule compact.

Then you will do a check, whether there is a schedule of the same name in the IDF.

If you follow these steps, you will be a good programmer as well.

Using the third party GUI will start your fast and the very difficult to expand your scope later on.
====================
This is my additional remarks for all the users of EPlus. Pay more attention to the IDF program entries and not just having pretity building pictures with many warnings and errors.

Dr. LI.

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