Boiler Question

[timmy2734]

As I stated earlier anything built 1981 or prior usually has a full central plant system including steam or HW heat provided by boilers, district steam, and heat recovery chillers. Anything built after about 1982/3----to the present seems to utilize electric heat, hence the examples I listed. I could show you brand new properties and you would see DX units and electric heat.

Dude, once again, you're wrong. I posted about 4 buildings last page, with the oldest being 2008. No electric heat in sight.

The funny part is, that I'm not annoyed one bit nor do I think anyone else is.

[GT Jets]

As I stated earlier anything built 1981 or prior usually has a full central plant system including steam or HW heat provided by boilers, district steam, and heat recovery chillers. Anything built after about 1982/3----to the present seems to utilize electric heat, hence the examples I listed. I could show you brand new properties and you would see DX units and electric heat.

The highlighted area is where you lose me completely... This information is wrong for MOST areas of the country... The DX units you are mentioning are more than likely going to be heatpumps.

Look up FHP (Florida heat pumps) these are water to water heat pumps. Also look up CHP (California heat pumps) these are water to air systems. Both considered DX when loosely translated.

When done correctly, these systems can be crazy efficient and provide an almost perfect environment.

As stated before, you would never get a building permit here in Silicon Valley for all electric heat... Not in a million years. This is why I am so passionate about letting you know that what you are saying is not accurate. If you ever move out of Dallas you will be totally lost.

GT

[MHall]

The highlighted area is where you lose me completely... This information is wrong for MOST areas of the country... The DX units you are mentioning are more than likely going to be heatpumps.

Look up FHP (Florida heat pumps) these are water to water heat pumps. Also look up CHP (California heat pumps) these are water to air systems. Both considered DX when loosely translated.

When done correctly, these systems can be crazy efficient and provide an almost perfect environment.

As stated before, you would never get a building permit here in Silicon Valley for all electric heat... Not in a million years. This is why I am so passionate about letting you know that what you are saying is not accurate. If you ever move out of Dallas you will be totally lost.

GT

What about heat recovery chillers for hot water heating? I am being completely honest, when I say that this application seems quite rare. I have only heard of one building in my area, (and it is an older building), that utilizes this type of system.

[timmy2734]

I've never seen one.... Surely you could use it to preheat your water, but I think that you'd still need a dedicated hw heater.

found some reading material

http://www.mcquay.com/mcquaybiz/lite...er-HeatRec.pdf

http://www.johnsoncontrols.com/conte..._%28510%29.pdf

[GT Jets]

What about heat recovery chillers for hot water heating? I am being completely honest, when I say that this application seems quite rare. I have only heard of one building in my area, (and it is an older building), that utilizes this type of system.

This is actually the beautiful part about WSHP systems, lets say I had twenty heat pumps heating and 15 heat pumps cooling, I would not have to inject any heat nor would I have to reject any heat. I would simply be taking the heat from once space and moving it to another.

I know that is not what you are referring to, but it works out the same.

It is not (as far as I know) a widely used system because of the small window of utilization versus the expense and maintenance involved. You need to have really warm condenser water to be able to get much use out of it, and that takes most modern chillers out of their "comfort level" as far as efficiency. Think about it this way, most newer chillers like the coolest water possible for the condenser (in the low 70's), raising that temperature enough to gain much sensible heat out of it (high 80's) would likely negate any gains from recovering the heat.

Hope I didn't con-volute the crap out of that, I get the feeling I did.

There are chillers specially designed for this use and I don't think the total efficiency is there yet.

What seems to be on the cutting edge these days is in the refrigerant side for economizing with liquid refrigerant. The biggest issue so is the vast quantity of refrigerant required to accomplish it.

GT

[MHall]

This is actually the beautiful part about WSHP systems, lets say I had twenty heat pumps heating and 15 heat pumps cooling, I would not have to inject any heat nor would I have to reject any heat. I would simply be taking the heat from once space and moving it to another.

I know that is not what you are referring to, but it works out the same.

It is not (as far as I know) a widely used system because of the small window of utilization versus the expense and maintenance involved. You need to have really warm condenser water to be able to get much use out of it, and that takes most modern chillers out of their "comfort level" as far as efficiency. Think about it this way, most newer chillers like the coolest water possible for the condenser (in the low 70's), raising that temperature enough to gain much sensible heat out of it (high 80's) would likely negate any gains from recovering the heat.

Hope I didn't con-volute the crap out of that, I get the feeling I did.

There are chillers specially designed for this use and I don't think the total efficiency is there yet.

What seems to be on the cutting edge these days is in the refrigerant side for economizing with liquid refrigerant. The biggest issue so is the vast quantity of refrigerant required to accomplish it.

GT

Thank you for your informative post. I greatly appreciate you taking the time to explain the system’s operation. Tomorrow I will post some more questions.

[GT Jets]

Thank you for your informative post. I greatly appreciate you taking the time to explain the system’s operation. Tomorrow I will post some more questions.

You are very welcome.

Just one last jab before I go do a high intensity light filtering eyelid performance check...

If you have a heat recovery chiller (duplex condenser) you have to have a hydronic heating loop regardless, so technically speaking this would be a great retrofit to an existing building with separate systems. Especially if there is a really consistent load on the chiller (like a manufacturing facility with office space).

GT

[Gus-Herb94]

As I stated earlier anything built 1981 or prior usually has a full central plant system including steam or HW heat provided by boilers, district steam, and heat recovery chillers. Anything built after about 1982/3----to the present seems to utilize electric heat, hence the examples I listed. I could show you brand new properties and you would see DX units and electric heat.

You have said this a couple times but you can't be more specific as to WHERE your referring to? Is this a blanket statement for the whole country or are you referring to your city Dallas? and have you actually seen these electric heat strips your talking about or are you taking somebodies word for it?

I can think of at least one building built before 1981 that does not have a "full central plant" and that would be the Sears tower (Or Willis tower as you probably only know it as at this point). It has water source heat pumps (I haven't seen this for myself, but have heard this from quite a few techs around this area). That was completed in 1973.

[ckartson]

Requirement is based on boiler horsepower. 30 hp and greater. hense the ohio special only 29 hp

[MHall]

I've never seen one.... Surely you could use it to preheat your water, but I think that you'd still need a dedicated hw heater.

found some reading material

http://www.mcquay.com/mcquaybiz/lite...er-HeatRec.pdf

http://www.johnsoncontrols.com/conte..._%28510%29.pdf

My question concerns the operation of heat recovery chillers for hot water space heating. Not domestic hot water.

[timmy2734]

No worries. It is performing the same function though. It's all just going into a heat exchanger.

Have you ever checked out tecogen chillers?

[MHall]

Another question that came up; "Are heat recovery chillers used in any new buildings for space heating?"

The application seems so rare altogether, that it seems unlikely. As I stated earlier, I had never heard of them until I read about a system that was installed in an older building in my area. I have never seen any in person. Given their obscurity, perhaps they fell out of fashion because a boiler is used as a supplement? Or perhaps they fell out of use for the same general reasons that boilers and hydronic heating have.

I no others stated otherwise, yet I believe one reason hydronic heat has fallen out of favor is because of the piping. With electric strips, you have no steam or hot water supply/return piping.

Comments are appreciated.

[meplumber]

Another question that came up; "Are heat recovery chillers used in any new buildings for space heating?"

The application seems so rare altogether, that it seems unlikely. As I stated earlier, I had never heard of them until I read about a system that was installed in an older building in my area. I have never seen any in person. Given their obscurity, perhaps they fell out of fashion because a boiler is used as a supplement? Or perhaps they fell out of use for the same general reasons that boilers and hydronic heating have.

I no others stated otherwise, yet I believe one reason hydronic heat has fallen out of favor is because of the piping. With electric strips, you have no steam or hot water supply/return piping.

Comments are appreciated.

Dude, you are reading but aren't listening. We have all tried to tell you the same thing. NOW PAY ATTENTION.

Every area of the country, and the world for that matter, has different heating and cooling needs. For instance, Bangor, Maine has extremely high heating needs and very, very low cooling needs, where Houston, TX has very, very low heating needs and extreme cooling needs. A heating system that works in Houston, will not even make a dent in Bangor. Your fascination with electric strip heat is horribly misguided. I have been doing this for twice as long as you have been alive, and I can count on one hand, the buildings both new and old that used strip heat. This includes a considerable amount of time working in Atlanta.

Heat recovery chillers are but one tool in an engineer's toolbox of tricks to heat and cool a building. Every type of system has its strengths and weaknesses. This means that there is no "one size fits all" HVAC system that can dominate.

For instance, take a brand new hospital that we are working on. It will be heated with a system that starts as 60 PSI steam and then is exchanged to 180* water through HX's. The cooling needs are primarily handled by chillers. Air handlers, commercial baseboard, and hydronic radiant panels will deliver the heat to the space. This is a brand new, state of the art hospital and I can guarantee you that there will not be a single electric duct heater in the building. Why? Because in Maine, electric heat is inadequate and expensive.

Please listen to those that are trying to educate you or we will all stop wasting our time trying to argue with a high school kid.

My $0.02 worth.

[MHall]

Dude, you are reading but aren't listening. We have all tried to tell you the same thing. NOW PAY ATTENTION.

Every area of the country, and the world for that matter, has different heating and cooling needs. For instance, Bangor, Maine has extremely high heating needs and very, very low cooling needs, where Houston, TX has very, very low heating needs and extreme cooling needs. A heating system that works in Houston, will not even make a dent in Bangor. Your fascination with electric strip heat is horribly misguided. I have been doing this for twice as long as you have been alive, and I can count on one hand, the buildings both new and old that used strip heat. This includes a considerable amount of time working in Atlanta.

Heat recovery chillers are but one tool in an engineer's toolbox of tricks to heat and cool a building. Every type of system has its strengths and weaknesses. This means that there is no "one size fits all" HVAC system that can dominate.

For instance, take a brand new hospital that we are working on. It will be heated with a system that starts as 60 PSI steam and then is exchanged to 180* water through HX's. The cooling needs are primarily handled by chillers. Air handlers, commercial baseboard, and hydronic radiant panels will deliver the heat to the space. This is a brand new, state of the art hospital and I can guarantee you that there will not be a single electric duct heater in the building. Why? Because in Maine, electric heat is inadequate and expensive.

Please listen to those that are trying to educate you or we will all stop wasting our time trying to argue with a high school kid.

My $0.02 worth.

Thank you for taking the time to offer an explanation. As I said earlier I am not trying to come across as disrespectful, I am just attempting to research my question thoroughly before jumping to an agreement with what one or two people say.

Those I’ve spoken to personally give the impression that boilers and hot water/steam heat are old technology installed in only older buildings. Those here, argue otherwise. I am just trying to look at both sides and discuss this intelligently.

Still, I find it very hard to believe that a brand new hospital would use live steam for heat. That would mean an operator has to be present 24/7. Are you sure this isn’t a renovation of a much older building??I thought the goal in today’s economy was to avoid a large onsite staff?

And with LEED certified buildings dominating new construction, steam seems the least likely choice for something new and efficient.

Again, I’m not trying to argue. It just seems I’ve now been told two things……..

[meplumber]

Thank you for taking the time to offer an explanation. As I said earlier I am not trying to come across as disrespectful, I am just attempting to research my question thoroughly before jumping to an agreement with what one or two people say.

Those I’ve spoken to personally give the impression that boilers and hot water/steam heat are old technology installed in only older buildings. Those here, argue otherwise. I am just trying to look at both sides and discuss this intelligently.

Still, I find it very hard to believe that a brand new hospital would use live steam for heat. That would mean an operator has to be present 24/7. Are you sure this isn’t a renovation of a much older building??I thought the goal in today’s economy was to avoid a large onsite staff?

And with LEED certified buildings dominating new construction, steam seems the least likely choice for something new and efficient.

Again, I’m not trying to argue. It just seems I’ve now been told two things……..

It is a new hospital. I was there yesterday, all day. The building is striving for LEED Platinum certification.

Hospitals and many buildings like it are moving toward Co-Generation. Meaning that they are producing their own electricity along with heating in the same plant. Steam is far from lost. Steam can move freely without the use of pumps, when designed and installed properly. Think of it thermodynamically. Steam is latent heat in its purest form.

[MHall]

It is a new hospital. I was there yesterday, all day. The building is striving for LEED Platinum certification.

Hospitals and many buildings like it are moving toward Co-Generation. Meaning that they are producing their own electricity along with heating in the same plant. Steam is far from lost. Steam can move freely without the use of pumps, when designed and installed properly. Think of it thermodynamically. Steam is latent heat in its purest form.

Interesting information. Would co-generation, require a boiler? Based on what others have said I always thought that emissions would be a great part of why new buildings don't want a boiler on the property. Isn't live steam dangerous as well?? I find it hard to believe that a new LEED hospital will use steam for space heating. Wouldn't that require a boiler operator on site 24/7??

[SolarMike]

Young feller. Not only is water heating still going strong but it is getting stronger. Floor heating and fancy European radiators have given it new life. So has state of the art boilers, that don't need to be monitored. Just so you know, there is almost no air heating systems in Europe (500,000,000 people) except for some commercial cooling and heat pump systems. You can move more heat in a 1" pipe than you can in a 1 ft2 duct and at less electrical cost to move it, so don't listen to people who tell you it is on its way out.

Steam has its place and there are some situations where almost nothing else works....bakeries, for example, commercial laundries as well. Each technology has its place and you have to separate the creation of the heat (gas, oil, electricity) from the distribution of that heat (forced air, water or steam lines).

[meplumber]

Interesting information. Would co-generation, require a boiler? Based on what others have said I always thought that emissions would be a great part of why new buildings don't want a boiler on the property. Isn't live steam dangerous as well?? I find it hard to believe that a new LEED hospital will use steam for space heating. Wouldn't that require a boiler operator on site 24/7??

Hospitals have to have process steam anyway. So operators are required onsite for those boilers. Their heat is most often pulled off of these boilers.

It is not hard to gain LEED certification with boilers. There are just stringent emissions standards. Those standards are already in place and the boiler manufacturer's are already building their equipment to suit those requirements. If you don't believe that steam is alive and well, take a trip to Maine and I will show you the beauty of the future of steam and hydronics. Yes, Co Generation requires a boiler to make steam to turn the turbine. The emissions standards that you keep referring to, only apply above certain BTU or HP levels. Live steam is dangerous, but so is natural gas and propane and high voltage electricity. R-410A operates at 400 PSI high side pressure, that is far higher than almost all steam systems with the exception of manufacturing process steam.

[SolarMike]

Interesting information. Would co-generation, require a boiler? Based on what others have said I always thought that emissions would be a great part of why new buildings don't want a boiler on the property. Isn't live steam dangerous as well?? I find it hard to believe that a new LEED hospital will use steam for space heating. Wouldn't that require a boiler operator on site 24/7??

Co-generation needs a flame and heat. some systems don't need steam but most do. There are small household systems that will supply hot water for the house and make some electrical power at the same time. In most western countries, new power plants are co-gen or combined cycle and some supply waste hot water to heat homes and businesses in the area of the plant. Combustion rules and emissions don't differentiate by the type of distribution so boilers are typically the same or less than gas forced air.

[rich pickering]

Up here in my part of the great white north, there is no such thing as strip heat in commercial.