Heating Help

How about both?

@ May 14, 2012 12:03 PM in Commercial Garage Heat

DISCLAIMER:  I am not a heating professional.

Since you will have large peak loads from when a cold truck comes into the garage, why not install right sized both systems?  Use the high mass slow changing radiant floor to maintain the building temperature and use auxillary overhead radiant to provide the rapid heat to warm up the large trucks when they initially return.  The floor will provide some comfort when working under the trucks and act as a baseline load for the heating system.  The overhead radiant can be a seperate redundant system for peak heating needs.

Bumpedy Bump Bump

@ April 24, 2012 4:49 PM in Steam Heat Not Reaching certain areas in old building

156,

Anything new on the update or survey fronts?

Larry C

Same idea but different.

@ April 19, 2012 11:27 PM in need a reasonablly-priced tankless water heater as a temp

Same idea but different.

Temp in a oil or propane unit that is installed in an enclosed structure on a trailer.  Basically a water heating system on wheels.  Somewhere on the wall I saw a picture of someone who put a furnance on some pallets and used it to keep a concrete slab warm during a winter construction project.

If the load is big enough, you can rent entire heating plants on semi-trailers for temporary installations, but of course you already knew that.

Didn't somebody else asked about putting a steam boiler in a box truck for a portable kitchen?

Dirt on the radiators?

@ April 16, 2012 10:30 AM in Steam vs hydro air for allergies

Another possible explanation is that the air currents set in motion by the heated radiator, is lifting dirt that was sitting on / behind / below the radiator and sending it airborne.  Try blowing air under the radiator and see how much dust and dirt goes airborne.

A different possibility is that the radiators have something on them that outgasses when the radiator is heated.  Was the previous occupants smokers or were the radiators painted sometime in the last several years?

Do not know if this would work.

@ March 31, 2012 7:05 PM in cleaning baseboard elements

I do not know if this would work. 

How about removing the covers and using a tank garden spayer with a soapy water mixture to mist spray down the fins, followed by a clear water rinse?  Obviously towels would be required to collect the runoff, and care is required to not excessively wash down the wall and floor.  Minimal airborne particles and with plenty of towels, no puddles.

What is the dust from?  Smoking, soot, animal fur, house fire, cooking fumes. or other. 

409 Cleaner is great for cutting oily  or greasy dirt.

Questions

@ March 29, 2012 10:05 AM in Steam or water system for old Hotel

Location of building?

Design temperature and need for modulation of heating plant?

Does the landlord want individual room temperature control?

Fuel preference?

Any future plans for adding other heat sources like solar, geothermal, wood, or other solid fuels?

Desire for A/C in retail space or rental spaces?

Limitations on time of day when the building is occupied? 

Please do not give up the steam system.

@ March 21, 2012 5:03 PM in 1940's Steam System - Oil to Gas Conversion -- Thinking of Going to Forced Air

"1) We will switch from our our old oil steam boiler to a new natural gas steam boiler. Replace all the pipes with copper. Remove the old boiler. Run a gas line from outside the house (the house already has natural gas for the hot water heater). Cannon would be the brand for the new boiler replacement."

Why are you replacing all of the pipes with copper?  Are you talking about the steam lines?  It is not recommended to pipe steam lines in copper.  The coefficient of thermal expansion for copper and steel are much different.  When the piping heats up, the greater expansion of copper could put alot of stress on the boiler piping and lead to significant mechanical problems.

"Issues we have. If we replace the boiler downstairs we need to have the boiler and the pipes abated because they are asbestos before I can replace it."
I don not know the law about asbestos abatement requirements, but perhaps they can just seal the asbestos insulation without removing it. If the sealing could be done, then I ASSUME the only asbestos that would have to be removed is the insulation up to the point where the new boiler mates with the existing steam piping.
It may make sense to get a steam pro in there to determine if there are any other issues that need to be fixed when the boiler is replaced.

Have you done significant upgrades to the building as far as insulation, new windows, house wrap, and other energy conservation activities?  Having a heatloss calculation performed could show that the existing system is much to large.  Perhaps the amount of radiation can be downsized and therefore a smaller boiler be installed.  Right sizing the boiler will also reduce your ongoing energy costs.

Good luck on the upgrades.

Duplicate

@ March 20, 2012 1:27 PM in Water not going to boiler

Any updates?

@ March 20, 2012 1:27 PM in Water not going to boiler

156,

Any updates?

Did you check out the condensate receiver water level?

Larry C

At least two issues. Slow condensate and water loss.

@ March 15, 2012 4:08 PM in Water not going to boiler

156,

It sounds like you have at least two issues.  Slow condensate return and water loss.  If it was just slow condensate return, I would assume that most of the missing water would show up by the next morning.  Since the system apparently shuts off due to low water and the sight glass still remains empty the next morning, I assume the water is "lost".

Does the condensate receiver have some sort of sight glass where you can check the water level? 
If the receiver water level is low, that means the water is not making it back to the tank.  Where is the water?  Stuck behind trap(s) perhaps?  Lost up the chimney?  Hiding in radiators with bad air vents that do not let air back into the radiators?
If the receiver tank water level is high, why can't the water leave?  Bad pump, bad pump switch, clogged flow path, excessive boiler pressure?
Do you have a bypass valve around the trap feeding the condensate receiver?
If you open the condensate return piping drain valve, do you get an excessive amount of water?
Excessive water out of the condensate return piping drain valve could indicate a stuck shut or clogged trap between the drain valve and the receiver.

Any progress with the trap survey and repair?

You are making steam.

@ March 2, 2012 11:00 PM in Expansion tank issues

" While the boiler is running at +- 18psi, all on a sudden within 2-4 seconds the pressure raises to 30psi and blows the pressure relief.  Temperature doesn't appear to have any bearing.... "

I am guessing you are making steam in the boiler.  The expanding steam bubble raises the pressure and pops the relief. 
Is a Taco 014 a small pump?  Is that pump recommended for the boiler circulator in a primary secondary set up?
If that is the correctly sized pump, then I would look for a hot spot.  Perhaps a blocked water passage, improper firebox conditions, or improper flame size.

Be aware I am not a heating professional and my advice is worth exactly what you paid for it.

Good Luck.

Cruise control analogy

@ March 1, 2012 4:06 PM in Actual heat loss vs. calculated heat loss....

Ice,

Your heating system has cruise control !  That is what the thermostat does.  When the house is below the setpoint, it turns on the heat.  When the house is at or above the setpoint, it turns off the heat.  It maintains the house at or around the setpoint.

I think what you want is a heating system that controls the rate of heat being added to the house depending on how far away from the setpoint the current temperature is.  You could have a quick responding system if you had a high firing rate system, but then people would be complaining about short cycling.

ODR curves, and high mass storage are ways to limit the temperature variations.

How did they control water level in the steam generators?

@ February 24, 2012 10:47 AM in Using a shell & tube heat exchanger as a steam generator.

Jim,

How did they control the water level in the steam generators?

This is definitely not happening in my house.  I am just trying to determine a safer way to generate 90 psi steam than welding heating coils into an existing tank.  I am thinking the quantity of steam they will be needing is no more than one BHP (Boiler Horse Power) or 34.5 lbs of steam at 212 F.

Larry C

Safety concerns.

@ February 23, 2012 5:43 PM in Using a shell & tube heat exchanger as a steam generator.

Ice,

I agree with you 100% about the safety concerns.  That is why I suggested using an appropriately rated heat exchanger to start with.  I also mentioned the need for safety valves for both overpressure and underpressure situations.  Safely maintaining correct water levels is a major hurdle to solve too.

I am thinking this method is a heck of a lot safer then their original plan of using a non rated tank and just using a copper coil to pump heat transfer fluid thru it.  I understand their desire to create a functional steam boiler to drive a steam engine and I am trying to visualize a safe manner to do so.

As far as the 1700 times volume liquid to gas expansion concern, that is why I am thinking of using an oversized shell to hold the tube bundle to provide room for expansion along with room for the steam to dry out.

Anybody else have any comments?

@ February 22, 2012 10:20 PM in Using a shell & tube heat exchanger as a steam generator.

Does anybody else have any other input?  Am I pursuing a very expensive scrap metal sculpture?

Thanks,

Glad to hear you are making progress.

@ February 22, 2012 3:43 PM in Steam Heat Not Reaching certain areas in old building

156,

I am very glad to hear that you are making progress with the neglected / knuckle headed system. 

Have you contacted Barnes and Jones about performing a trap audit yet?

I am sure there will be more replacements.  Good luck in finding and fixing all of the failures so you end up with a quiet efficient comfortable building heating system.

EDIT 1:  Have you checked out the air vents on the steam mains and vertical risers?  Checking out means verifying proper vent operation and that they are correctly sized.

EDIT 2:  Any progress on finding or getting an accurate system diagram made?

First reply.

@ February 21, 2012 12:53 AM in Using a shell & tube heat exchanger as a steam generator.

Thanks for the responses.

From my understanding of boilers, the two basic forms of tubed boiler design are fire on the outside of tubes full of water to make steam inside the tubes, or running heat thru tubes to boil the pot of water.  The first method confines the steam to pipes, which are easier to make strong enough to hold the force of expanding steam.  Problem with the second method is that the boiler needs to be able to hold all of the force generated by the expanding steam. 

In a previous life I used to operate Pressurized Water Reactors (PWR) nuclear power plants for the US Navy.  Our boilers or Steam Generators are vertical shell and tube heat exchangers that used a inverted U shaped tube bundle.  The hot water that circulated thru the core of the nuclear reactor was pumped thru the tubes.  Secondary or steam plant water was pumped into the shell side, circulated around the tube bundles, where it boiled off into steam, went thru a moisture separator to dry out the steam and then it went off to the turbines.

My thought is to do the same basic idea.  Mount the HX vertical and pump 400 - 500 F working fluid thru the tubes, while maintaining a water level about half way up the tube bundle.  That might give enough of a steam chest to minimize the amount of water carry over coming out of the steam exit.

Safety issues include maintaining a correct water level while steaming, over and under pressure safeties, etc.  Materials would have to be compatable for all working fluids.

One thought that just occurred to me was to swap a longer but same diameter shell with a shorter tube bundle to increase the steam chest volume. 

The logic behind using an existing heat exchanger is that the engineering and construction is already done.  If the shell side is rated for MAWP of 150 psi, then we should have enough of a safety margin for system that would use 100 psi steam.  I am assuming the max pressure inside the tubes would be less than 60 psi.

My limited understanding of thermodynamics is that heat travels from hot to cold so the amount of heat flow is primarily controlled by delta T between the heat transfer fluid and the saturated steam, transfer area, and conductivity of the material.  Assuming there is not a condition of excessive buildup of steam clinging to the surfaces of the tubing due to excessive nucleate boiling.

Does my reasoning have any significant flaws?

Using a shell & tube heat exchanger as a steam generator.

@ February 20, 2012 5:15 PM in Using a shell & tube heat exchanger as a steam generator.

Would it be safe and make sense to use an appropriately rated shell and tube heatexchanger to make steam?

The application would be as follows.  The HX is designed for low pressure steam (less than 150 psi) on the shell side and used for heating the fluid in the tubes.  I am thinking of running it in "reverse". 

Using a concentrating solar collector to heat up a suitable heat transfer fluid, pump the HT fluid thru the tubes of the Hx and supply water to the condensate output of the shell.  The generated steam would need to go thru a moisture seperature to create dry steam, and then the steam would be used to drive a small steam engine to generate electricity.

Obviously overpressure safety reliefs would be required.  Yes, this is an off grid application.  Intended steam pressure would be around 80-90 psi.  The thought is to run the heat transfer fluid thru a phase changing salt to store heat during the day and to use the stored heat plus solar collected heat to run the boiler when there is enough energy to run the steam engine for several hours.

HX would be something like a Bell & Gossett SU85-2 or similar.

Some additional thoughts are mounting the HX vertically or tilting it up at a steep angle to maintain half of the tubes under water to maximize steam generation and modifying the shell to add an external sightglass.

Assuming the math pencils out, would there be any major issues besides the steam being generated would be wet.

Thanks.

http://www.genemco.com/catalog/pdf/HDAF869bellgossettspecs.pdf

Faster heating to end of line. Increase venting.

@ February 17, 2012 10:13 AM in Insulating basement pipes

To speed up the steam reaching the end of the heating mains, generally you would increase the amount venting so that the air in the main is removed faster.  Insulating the mains will reduce the amount of heat lost by reheating cold pipes.  Reducing the heat lost will also enable the mains to fill up with steam faster.

Another place to add vents or increase their size would be at the top of the vertical risers, assuming your steam travels from the basement up to the top of the building and horizontally out to the radiators.  Again, the idea is to remove the air quickly so the steam can enter the piping.

Does the boiler have the ability to burn at two different power levels?  It is called Lo Hi Lo or something similar to that.  The system would initially fire at a high level until the system is up to pressure, then switch to a low level to maintain system pressure.  If the steam pressure drops, the burner will go back to high level.  This helps match the fuel consumption to the actual heat demand of the building.

Too much heat could also be an indication that the steam pressure is turned up too high.  The turn off pressure should be set to about 1 to 1.5 psi max with the turn on pressure set about .5 psi less than max pressure.

Does the piping make noise like people are hammering on it?  How clean is the water in the sight glass?  Does it bounce up and down alot (more than 1/2 inch) when the boiler is operating?

I hope this helps.

P.S.  the owner of this website sells books and one of them is "We Got Steam Heat"  It helps explain how steam heat systems work and what can be done to keep them and You happy.

Amp clamp readings.

@ February 16, 2012 12:48 PM in Calculating cost of running electric motor?

Zman,

Measuring the current draw of the motor will give you the current of the motor.  I know, profound statement.  For a balanced three phase load, phase current times the phase to phase voltage times the square root of three will give you the apparent power.

Apparent power IS related to actual power, but they are usually not the same.

Apparent power is the vector sum of the actual power, which does real work, and the reactive power, which is the power that the load stores for a moment and then gives it back to the power company.  The ratio between real power and apparent power is the Power Factor.

For what you are doing, I think the apparent power is probably close enough for estimating cost savings.  If this was a large motor, let's say greater than 20 HP, then it would make sense to calculate real power.

current X phase to phase voltage X sqr root 3 divided by 1000 = KVA  (KW).
KW X 24 Hrs x cost per KW Hr = cost per day.

Aside from energy cost savings, will starting and stopping the motor lead to increased maintenance costs and shorter motor and connected mechanical load life?

DHW temperature setpoint?

@ February 15, 2012 9:03 PM in Facility Manager

"The domestic hot water loop is circulated and maintained at 120 F." 

ME, I thought you would have made a comment about the need to maintain the DHW temperature at 140 F?

ANY UPDATES ?

@ February 14, 2012 2:38 PM in Steam Heat Not Reaching certain areas in old building

156,
Any updates?