Steam vs. Hot Water vs. Heat Exchange in an Inn

amiebe

Thank you in advance for any advice! I have an old 3-story inn with an existing one-pipe, one zone, steam heating system. The radiators in the bedrooms do have adjustment knobs to (somewhat) regulate the temperature in each room, but I find that throughout the winter many of our guests are either too hot or too cold - often at the same time. I am considering switching to a hot water system so that we could zone the rooms, but this is very expensive. I have also looked into installing the Mitsubishi heat exchange AC units because they would let us remove the window unit air conditioners in the summer and can provide some level of heat in the winter - maybe enough to provide guest comfort? I can only afford to do one - if I should do either!

Brad White

Let's start

by working with the steam system. Let's not start by tearing that out until we have explored the causes, hows and whys of the current operation.



That you have (apparently), thermostatic radiator valves is great. But if the pressure has been running over 3 psi (many run more than that), that may exceed the valve ratings, hence they may not work as they are intended to.



Can you post pictures of a typical guest room radiator? The boiler including near-boiler piping from a few angles?



There are a lot of good people here, some of the best, in fact.



Where are you located?

Jamie Hall

As Brad...

(who is one of the best!) notes, your least expensive option is going to be getting your steam system working as it was meant to work -- which will provide nice even heat for your guests (they will even be able to control it!) and cause you the least headaches.



But... we do need those photos, and as much info. as you can give us on the system!

amiebe

Thank you and photos

Thank you for your responses - here are some photos! All of our radiators are different sizes - sort of depending on the size of the room, but not always.



In quoting for a new hot water system, the plumber spec'd for (2) Buderus G215/5 cast iron boilers with a two stage Taco reset. He also included a 119 Super Stor indirect water heater in addition to the 90 gallon Solar tank we already have that stores the warmed water from our 3 solar panels.



Currently both heat and hot water are served by the same boiler. The reason for the two boilers would be to separate the hot water from the heat so that we would not be running a big boiler all summer long just for hot water.



Thank You!

nicholas bonham-carter

steam at the inn, repair or replace

that boiler seems to be 1,200,000 btu, just a little bigger than mine, which supplies 55 radiators. i also began to think that our 1-pipe steam would never be comfortable. after a new boiler, this time with proper piping, and a number of changes, such as those we will suggest to you for your boiler; we are burning a third less gas than before. the additional benefit is the high level of comfort-no more freezing or roasting!

how old is your boiler?

can you post some pictures of the pipes coming out of the top of the boiler?

are you burning gas or oil?

when firing, can you tell us your pressure?

you will be amazed how nice steam heat can be when all the deferred maintenance has been performed, and you will save enough fuel money soon to buy those mitsubishi a/c's!

can you show us a closeup picture of the boxes in the last picture probably labled "pressuretrol", or "vaporstat"--nbc

amiebe

More photos

Hi. We burn Oil and use about 4000 gallons a year. I would love to save 30% on that bill - and that is what I was hoping a switch to hot water would do for us! I think we have around 22 radiators, but some of them are huge. After cranking it for about 10 minutes it got up to a "4" on the main gauge. It usually takes about 25 minutes for the steam to get up to the 3rd floor and it is a very "all on" or "all off" feeling all around. The basement where the the boiler is located is always very warm - so much so that there are very few radiators actually on the floor above it.



Here are photos of the main gauge, the vaporstat and pressuretrol, the pipes coming out of the side and the two big pipes coming out of the top.

nicholas bonham-carter

steam for the inn

only time for a short reply for the moment.

a changeover to hot water is not advised, as the pressure in the system will be much higher, and give rise to leaks. also the radiators may not be big enough to give off heat from water which is 170 deg, instead of 212 deg. you would have to change the radiators, and supply pipes to be safe.

1. as far as i can see from the photo, the supply pipes at the top are not piped as the burnham manual would require, which no doubt is pushing water up into the mains along with the steam. we'll find a picture of your model piped properly, and post it, if you tell us your model no.

2. your pressure seems much too high at 4 psi. that over-pressure may be the cause of the thermostatic vents on the rads not doing their best for comfort. and yet i don't know why the pressure is so high, as you have a vaporstat, which should be keeping the pressure well under 16 ounces. it must need cleaning. my system vents the air out by the time pressure is 2 ounces, and will only get up to the cut-out during very cold, plunging temperatures  i don't use set-backs].

can you take some pictures of your main vents which could be on the return piping coming back to the boiler. they are either tuna can shaped. or rocket-shaped.

now i believe that the vaporstat pigtail is mis-oriented by 90 deg. so that as the pigtail heats up it changes shape, and throws the vaporstat out of the horizontal, thus affecting its pressure range. maybe someone else will double check my diagnosis on that. what is your location?--nbc

nicholas bonham-carter

more thoughts

this may be the model you have, or similar. see page 34 of the link below of the installation manual.

http://www.usboiler.burnham.com/pdf/101269-01R4%20(web).pdf

see how the riser pipes extend up quite a distance to keep water out of the steam, unlike your installation. this piping layout is the minimum requirement for this boiler, and naturally an experienced steam professional could improve it even more.

has any sort of combustion test been performed on your burner recently to make sure you are getting all the heat out of the oil?

is your burner a 2-stage model, or hi-lo-hi, which would economise on consumption?--nbc

amiebe

Boiler specs

This is, of course, way more technically complex than I can understand, so thank you all for your patience! I couldn't find the main vents..... so I took another picture of the pipes at the top - would it be on one of these pipes?



The current replacement plan would be to repipe the entire system and put in new radiators (baseboard style or wall panels maybe) for all except I think 7 of the old cast iron radiators which can be re-used. (I have also been curious about the whole PEX vs. Copper debate - given the price of copper these days).



The plate on the front of my boiler has the following info:

Boiler Number: PF 508

Serial Number: 7584173

Gross Output MBH: 1282

Net IBR Ratings

Steam Sq Ft: 4016

Steam MBH: 963.9

Water MBH: 1114.8

Firing Rate

Lt Oil GPH: 11.20

Gas MBH: 1568

ASME Maximum Working Pressures

Steam: 15 psi

Water: 50 psi

Minimum Relief Valve Capacity: 1282 MBH



Thank you!

amiebe

I forgot my location...

is Arlington, VT which is in the Southwest corner of the state - just north of Bennington.

amiebe

This is my boiler....

http://burnhamcommercialcastiron.com/pdf/52009N-8-94.pdf



I don't know exactly how old it is. More than 15 years old I think - this manual looks to be 20 years old, but I don't know how many years they made the PF-5 series.

Steamhead

The pigtail underneath the Vaporstat

looks like it's steel. Steel pigtails tend to rust shut, and that would explain why the pressure is getting so high. The Vaporstat should be keeping the system pressure below a pound. Replace the pigtail under the Vaporstat with a brass one, and under the manual-reset Pressuretrol if it's also steel. 



For TRVs to work right, the pressure must be kept very low. 8 to 12 ounces is good. Higher pressure will simply cram more steam into the radiators by compressing the air that the TRVs have trapped therein, and the rooms will overheat.



The mains should be vented well enough so the air will vent quickly at an ounce or two of pressure. Measure the length and diameter of your mains and we can tell you what you need.



The sight glass looks like someone has jacked it up higher than it should be. The water level is thus higher than normal, and that's probably making wet steam. Add to that the short risers coming out of the boiler and the steam is even wetter. Wet steam is garbage- you can't really heat a building with it. The risers should top out at a minimum 24 inches from the boiler's waterline.



You can cut your fuel consumption without an expensive and dicey hot-water conversion. The return on your investment will be much better.

Brad White

The PF-5

was discontinued about 15 year ago as a model name as I recall, but is now still made as the V11 series. The PF stands for "pressure fired". I imagine the castings are the same, just re-branded, should you need a repair.

Brad White

I know Arlington

Norman Rockwell's summer home. I used to have in-laws in Williamstown, MA and have too much Bennington pottery



Sorry this is a busy patch for me, I would otherwise be willing to take a road trip for the fun of it.

nicholas bonham-carter

Rx for steam system

here are a few simple things you can have done as soon as possible to make the system better. i suppose you are dependant on your oil company for maintenance, but any handy person [including yourself] will be able to do this.

1. find 2 new pigtails made of copper, if possible, and replace those now on the boiler. orient the "eye" of the pigtails 90 deg, so that you cannot see it. this will require some temporary unwiring [label the wires going to each]. if no new pigtail is available, then the ones you have should be cleaned to a blow-through condition. verify that they both work, by tripping the interior switch with a pencil while the boiler is firing. if your assistant is top-notch, he could put both pressure controls on 1 pigtail with a tee. at some point you will want to have a good low-pressure gauge  mounted along side the 2 controls, [gaugestore.com 0-3 psi], so you can verify your pressure to be within the range of the vaporstat [4-8 ounces] any higher pressure is not needed, and is a waste of fuel. unfortunately, the  0-30 psi gauge, useless for our diagnostics will have to remain somewhere on the boiler.

2. ask the tech to show you your main vents, and take pictures for posting here. if  he is capable of testing them, so much the better. they can sometimes be cleaned by soaking in vinegar and water, but are usually in need of replacement with new ones which are much more capacious. their job is to allow the air in the pipes to escape as the steam is rising. many misinformed people think the radiator vents can do this job, but they cannot. those rad vents will only take care of the air in the radiator and immediate piping. as a result, extra for the owner is paying the fuel company extra for forcing the air out.

if the tech is from the oil company, ask him to do a combustion analysis, using a piece of test equipment, known curiously as a combustion analyser, to make sure you are wringing all the heat from your oil.

also tell us where your thermostat is located.--nbc

Rod

Steam Pro Near You

There is a really good heating man and steam expert located fairly close to you in Lennox Dale, Mass. He is listed in the "Find a Contractor" section on this website.  Here is a link to his address and phone number:

http://www.heatinghelp.com/professional/221/Charles-Garrity-and-Son-Plumbing-and-Heating

Charlie from wmass

The vent on those TRV's is not what I use

We use much faster vents as when they open you need them to work fast. Yes 1/3 is a possible savings We all have stories of 50% savings but they were with systems in quite poor condition. I would be happy to survey your system and give you some concrete ideas and recommendations on getting better comfort and economy with out tearing apart your Inn. Looks like a nice place by the way.

Steamhead

I'll second that

Charlie's one of the best. 

Jamie Hall

And I'll third that...

Charles is one of the best in the business, and you are just a short drive away.  Do yourself (and your fuel bills) a big favour and give him a ring and have him come out and work on your system!

amiebe

Thanks - I have emailed him!

Thank you for all of your advice - I have emailed Charlie to see if he will come and give me a consultation!

Charlie from wmass

Amie I did reply to your email

I am not sure if you received it yet as I have not heard back from you.

tim smith

Re: boiler change

The least expensive way to get more comfort and save fuel costs would be do what all have said above and switch out the burner to a power gas or dual fuel burner if gas available. I am not sure what your local NG rate is but I am sure if you calculate it out you will probably save close to 30% to 50% on your energy dollars fore heat anyway.

Charlie from wmass

Who has priced

a dual fuel burner lately? I just priced one and The people definitely got sticker shock. Good one are very involve units to design and run. This being a Vermont Inn I am guessing the gas on hand will be L.P. not really a big savings there. The only big savings I see changing fuels for the long haul is getting properly piped and sized boilers connected. The fuel choice I do not see as being as important as the installation. That said I prefer installing and maintaining gas boilers. 

amiebe

Fuel switch?

Hi all,

We don't have natural gas available here and I do have one building on propane hot water right now, but my gut has been that the oil has been the better choice.