old radiator system

bauer

Hello...

I have posted here in the past regarding my heating system, but haven't settled on a plan of action as of yet. I have read "pumping away" and successfully re-piped other boiler systems and just recently received 'classic hydronics' to help in my plans, but I am looking for advice as to the best course of action.

Current set-up:
- 3000sq ft farmhouse (built in parts between 1830-1860)
- cast iron radiators on floors 1 and 2, piped as a single zone to a newish well-mclain boiler. Many of the pipes in the basement are what I assume to be from a gravity system as they are fairly large (two-pipe). At the boiler, these large cast iron pipes are reduced to 1 1/4" copper
- 3rd floor is electric resistance baseboard heat only

I am looking for better efficiency and heating -- we use a ton of fuel right now without much heat. I am planning on air sealing the entire attic,replacing or re-sealing windows and replacing old exterior doors. What I am trying to settle on is how to best upgrade the heating system. We are planning being here for awhile.


In reading classic hydronics, I see that Dan notes that new condensing boilers work very well with old gravity-piped systems --- so I am confused as to whether it would make more sense for me to plan on replacing my boiler with one of these, or re-piping my gravity system to a home-run manifold system with pex-al-pex. If I did decide on eventually replacing the boiler, I would prefer to do a heat-loss calc and buy a boiler that would be capable of serving the 3rd floor as well.... but again this comes back to whether or not to use the existing gravity pipe layout or re-piping the entire system.

any thoughts are greatly appreciated!

Paul48

First.....I'd be looking at why the existing system doesn't heat well. I'd do the heat loss now and check radiation against that.

icesailor

Those old farmers in 1830 to 1860 were more interested in getting the rock weeds out of the fields. If they didn't have a lot of rocks growing in the fields, they did without the cellar. They usually had rubble foundations on the ground and wood stoves. Fueled by the trees they cut down so they could find the rockweeds. If you take a ride in the farmland country and you see a lot of rubble rock walls, thats where they put the rockweeds. Most of those pre-civil war cribs had the wind blowing through them like a cheese cloth Curtin on an open window. And they dug tunnel/trenches in the crawl space to run the heating pipes.

The biggest improvement that you can make in your heating system is to keep the heat inside the envelope.

Buy a infra-red heat gun thermometer and shoot the floors and walls. If the floors and walls are cold, OPEC and the Wall Street Crime Syndicate salute you. For doing your part by wasting energy to their benefit.

Snowmelt

Bauer, your boiler is still a baby, most likely your lacking insulation and drafty windows, you mention the newer condensing boilers. I would recommend outdoor reset with a bypass to keep boiler from condensing.

bauer

i'm not dismissing the effect that my drafty windows & doors and insufficient attic air sealing & insulation have.... just looking at a plan for the heating system as well.

I'm heating way too much of my basement with those huge cast iron supply pipes - I was just curious as to which was a better option for them. I'm heating way too much extra water and iron that I am not using...

Paul48

Yeah.....Kinda like a big radiator under your floor. Who would want all that warmth coming up from the floor?

bauer

Hmm, sarcasm. clever, thanks.

The boiler & accompanying cast iron piping is located under a portion of our first floor that gets heat from our wood burner. The floor was also mistakingly insulated by the previous owner and removing that insulation is on my list. So as wonderful as a radiating warm basement/first floor sounds, I am trying to get more heat directed to other parts of the house.

Steamhead

Insulate the pipes.

Paul48

Just make sure you're not creating a condition that starts freezing domestic pipes.

icesailor

Steamhead said:

Insulate the pipes.

ABSOLUTELY.

And if you live in a State (like Massachusetts) where the building codes require that all heating and potable hot water pipes be insulated. check with insulation contractors. They can often insulate the whole job, installed, for less money than you can buy the insulation at a big box store.

Gordy

What's the boiler temp set at?

bauer

190 I believe.

My total plans include insulating basement walls as I do not want my basement outside the envelope of the home, so I'm not planning on insulating the heating pipes.

I can't see how reducing the size of those mains wouldn't result in faster heat response at my radiatiors, especially with the addition of TRV's. Going from 3"-4" mains down to 1/2" home runs (assuming that is enough after checking BTU of radiators) is almost a half gallon per foot of water less....

icesailor

Your understanding and my understanding are different. Especially when it comes to spending money and a ROI.

In a cellar, from grade down to the floor, the heat loss average is equal to a 2" X 4" frame wall with 3.5" of R11 insulation with plywood, paper and shingles with finished gypsum board on the inside. From the sill to grade is equal to X8 in heat loss.

bauer

Really not sure what your point is.... that insulating my basement walls is a waste of money in your opinion?

icesailor

Only that the major heat loss is from grade up. Grade down is almost inconsequential in the scheme of things.

Insulate all the pipes. There's a better bang for your buck and a faster ROI.

Jason_13

As steamhead stated "insulate those mains". That will keep the heat in. As icesailer stated ROI. Water volume is not always a bad thing. It is kinda like a built in buffer tank. When you get things tightened up and use ODR your water temp will never need to be 190f. The CI rads are a great source for low temp heating.

bauer

While ROI from an energy perspective is obviously one factor I consider, it isn't the only one. That being said see below ---


"If you live in Climate Zone 3 or anywhere colder, it’s cost-effective and wise to install basement wall insulation. This advice applies to those who live in most of New Mexico and most of Alabama, as well as all of Oklahoma, Arkansas, and South Carolina, and anywhere colder than these states. (Click here to see a climate zone map.)" - See more at: http://www.greenbuildingadvisor.com/blogs/dept/musings/how-insulate-basement-wall#sthash.e3kAywFM.dpuf

Aside from that, as I said I'm not really interested in the alternative...if I decide to instead insulate the heating pipes, I would then need to insulate and air seal the entire basement ceiling and weatherize the basement door to the first floor as the basement would then be treated as outdoor space.

icesailor

bauer said:

While ROI from an energy perspective is obviously one factor I consider, it isn't the only one. That being said see below ---


"If you live in Climate Zone 3 or anywhere colder, it’s cost-effective and wise to install basement wall insulation. This advice applies to those who live in most of New Mexico and most of Alabama, as well as all of Oklahoma, Arkansas, and South Carolina, and anywhere colder than these states. (Click here to see a climate zone map.)" - See more at: http://www.greenbuildingadvisor.com/blogs/dept/musings/how-insulate-basement-wall#sthash.e3kAywFM.dpuf

Aside from that, as I said I'm not really interested in the alternative...if I decide to instead insulate the heating pipes, I would then need to insulate and air seal the entire basement ceiling and weatherize the basement door to the first floor as the basement would then be treated as outdoor space.

That and less than $5.00 will get you the biggest of your favorite coffee at Starbucks. Including a decent tip for the Barrister.

In my experience. some of those writers that write for these homeowner/DIY magazines, don't have the sense that God gave a goose. Some of their "green ideas" actually cost more in the long run to operate, and repair the damage that it causes.

Common sense is not a monetary valve.

Cellar wall heat loss is a long established and peer reviewed subject. Show me the proof that you need to insulate the walls, and not the pipes. I'm not saying don't do it. But don't insulate the walls and not the pipes. Insulating the pipes is the priority. Not the other way around.

My last house in Massachusetts had 10" poured concrete walls, in a 28' X 50'+ cellar with one end open to floor grade with a big double 7' door and a standard 36" door. All my heating and water pipes were insulated. There was not an inch of insulation on any wall except the end wall which was a 2" X 6" framed wall with 4' X 10" concrete return walls. There was maybe 16" exposed above grade. When it was 10 degrees outside and howling from the NW, the cellar never went below 50 degrees, ever. The cellar floor is 50 degrees, because that is the heat of the earth. The opposite wall from the end opening was the garage. Which because I always had the doors closed, nothing ever froze in it. So, it was an average on the coldest day, above 35 degrees. And the floor stored heat and was above 45 degrees.

Oh, and my entire first floor floor space was insulated with 12" fiberglass. So, the cellar was insulated from the conditioned space.

Knock yourself out. Insulate it. Those crappy foundation vents needed to ventilate the space will be infiltrating enough cold (actually, they let enough heat out) that your cellar/crawl space will be the same as if you didn't insulate it at all.

And the same applied to all my other houses I built and lived in.

Another thing. There is more heat loss in the rim joist space if not properly insulated in the whole entire cellar or crawl space wall. I've seen professional insulators insulate cellar walls with Styrofoam (the only kind you can use because of combustibility) and leave out the proper rim joist insulation, and pipes froze.

bauer

green building advisor is hardly a homeowner/diy site, and Martin Holliday is far from the type of writer your suggesting...

anyway, I agree with you, rim joist insulation is often missed and extremely important. Not sure what your referring to with venting; I've never seen venting of a basement, and the vents for crawl spaces are no longer an advisable way to install/use & shoud be covered up anyway (along with proper crawl space insulating & 6mil plastic on the ground etc...)

if I was planning on keeping these huge cast iron pipes, I would do as Paul48 was alluding to... I would insulate my basement walls/rim joists, remove the insulation from the basement ceiling, and use the heat generated by those pipes to help heat the first floor.

The situation you describe in your old house seems completely appropriate --- you insulated the basement ceiling with 12" fiberglass, placing your thermal barrier there. I am just choosing to define my thermal barrier at my basement walls.

I'm still not convinced that my excess water in those pipes isn't a waste - I'm willing to be the guinea pig here and keep copius energy records to update on whether or not I saw a decrease in fuel usage. Honestly, even if it doesn't help I'm fine with it because I have smacked my head on those stupid things way too many times....

nicholas bonham-carter

When you talk about faster heat recovery being affected by the larger size pipes, are you concerned about temperature setbacks in your house. If so, then have a search here for setback, and draw your own conclusions about the advisability of them for short periods of time. If you are working on a church, where the heat must be up one time a week, then that is a different situation.
As regards various articles in the green movement magazines, and websites, I think the authors have commendable enthusiasm for energy conservation, but less practical knowledge/ experience in achieving their goals sometimes.
Use the app from the Slantfin website to analyse your heatloss, and play around with the R-value for the basement walls, to see what difference it makes in your situation.--NBC

icesailor

Some States (like Massachusetts) have built in regulations that increase heat loss with the idea of saving energy/heat. The requirement to ventilate soffits, roof slants and attics is about the most wasteful thing to ever come along,

Many, many regulations and practices work well in the Spring & Fall. In Summer and Winter, they are totally counterproductive. And the same applies in all parts of the country where you have high seasonal temperature swings. In New England, the requirement of soffit and ridge vents is totally inappropriate for energy savings in winter. Because instead of the unconditioned enclosed space being 1/2 the outside temperature, it is often the same as the outside. Which will double the heating load in the conditioned space. The same applies in Florida or other hot weather areas where the same requirements for soffit and ridge vents again make the unconditioned spaces hotter, and also increase humidity levels which will pass through the envelope and add to the cooling load.

I've never seen any of your green hero's discuss this issue. If brought up, they would probably ignore the question. I've read The Journal of Light Construction for years. They have discussed about every issue pertaining to energy codes there is. Many of them are totally wrong from a cross purpose situation. Those of us who have been stung by these dreams of the energy product manufacturing and their sales minions, leave us in the mud pie.

You don't have to look any farther than where the IBR/GAMA eliminated the part where the old IBR had set up lower OAT design temperatures to allow for infiltration in high wind areas. Where I used to live and work, (along with a similar place) they raised the maximum(minimum) cold outside design day by 15 degrees. That may be fine on paper, but when it blows daily well over 30 MPH, and the designing wind factor is only 15 MPH, you better make it up somewhere. And with all the cold buildings I have seen with people coming to this web site, someone screwed up. No one will own up.

Everywhere I go, the only thing brought up is "Manual J" By ACCA. Air Conditioning Contractors of America. An air conditioning program, adapted to heat. Heat as a secondary issue.

When your Green Hero writers are sitting in a cool office, they put on a coat. When the office is hot and humid, they put in a larger Air Conditioning system. And they have been convincing some that the way to Valhalla is through smaller and smaller boilers and heating systems.

I'm glad that I don't have to try and explain that contradiction to anyone that might call me about their new cold house.

RobG

I don't know what type of boiler you have but in my opinion you need to tighten up the envelope, use an outdoor air reset, insulate the mains and go with constant circulation to put the water you are heating where you want it- in the house!

bauer

Thanks for the advice all, I'm definitely going to do an ODR and probably TRV's, and I still consider reducing the pipe size a low risk investment and as I said they are just plain in the way... I will report back any changes if anyone is interested...

icesailor I'm sorry you have such a negative view of building science, we will have to agree to disagree. I don't have the time to explain roof/soffit venting to you, however - contrary to what you said - if you do a quick search at my hero's website you will find a wealth of info on it.

Jamie Hall

If it cheers you up any, bauer, I have an even dimmer view of the Green Heros than Icesailor does... for many of the same reasons.

Gordy

True green goes much deeper than many things they try to achieve.

Harvey Ramer

One of the green things often overlooked is our habit of throwing away perfectly good, functional things to replace them with new things.

Just sayin...

bauer

that's the american way Harvey...

icesailor

bauer said:

Thanks for the advice all, I'm definitely going to do an ODR and probably TRV's, and I still consider reducing the pipe size a low risk investment and as I said they are just plain in the way... I will report back any changes if anyone is interested...

icesailor I'm sorry you have such a negative view of building science, we will have to agree to disagree. I don't have the time to explain roof/soffit venting to you, however - contrary to what you said - if you do a quick search at my hero's website you will find a wealth of info on it.

Sorry, but I have had to deal with far too many green dreams that cost me money and reputation over some misguided idea.

Far too much "Green" schemes are not consumer driven but manufacturer driven. With us in the middle. And the consumer is left with the bag of used cat box liter. Then, some get "Green"
training that is totally bogus and wrong. Like the guy in Florida that told me that cold flows to heat, and dryness flows to dampness. That in a "Green" Florida home, you should hang up round flex duct at least 2' off the floor. So the now hotter and more moist air heats the ducts and the cooling dew points make the ductwork sweat. Dripping down into the insulation below it.

Green ideas are like that little boy in a poem my mother used to read to me. When he was good, he was very, very good. But when he was bad, he was awful.

SWEI

Too many "green builders" we see have an obsession with spray foam and near-complete ignorance of dewpoint issues in wall assemblies. Building Science Corporation has done a lot of work on this issue, but far too few are actually reading.

Just like old heating systems, it really pays to take the time to understand how old building systems actually worked (and didn't.) Some of it sucked, but some of it was sheer brilliance. Let's not lose the brilliance in our quest for newer, faster, and more plasticized.

bauer

SWEI I completely agree with you, there is a ton of mis-information out there, especially with regards to insulation and home energy performance. Unfortunately much of it comes from companies just preying on joe homeowner to try and get him to fork over 30k worth of 'upgrades' to save x% on his energy bills. Finding information in the right places is critical, and the website I referenced above is closely aligned with Building Science Corp or at the very least approved by it. Outside of that, there is a TON of crap out there.

Although I am relatively young in the contracting trade, I am empathetic to those of you who have seen things come & go as far as technology and ideas for the next greatest thing. However, I do think that the core concepts outlined by a corporation like Building Science are important to the future and need to be communicated with those of us in the field....

anyway... not sure how we got on that just from some simple pipe insulation. Again, I wasn't really disagreeing with any of you above with regards to insulating my cast iron mains.... just simply that I want to get rid of them so, at the very least, I don't know my head anymore.

Thanks again

nicholas bonham-carter

Here is why many would have you keep those large pipes, but insulate them thoroughly: Thermal Mass.
This large body of water in the pipes, stored in your system at the temperature set by the outdoor reset, can even out the disparity between the lowest firing rate of a mod con boiler, and the rate which is needed to maintain the loop temperature. This is more useful in the shoulder seasons of winter, and not the coldest days.
The aim is to have longer periods of firing, and longer burner off periods, and this requires heat storage.
I hope I have been able to make that clear, or if not that someone else can help out.--NBC

bauer

Completely serious question/not being a smarta**...... Why aren't new rad systems designedly/installed with large pipes then?

Abracadabra

bauer said:

Completely serious question/not being a smarta**...... Why aren't new rad systems designedly/installed with large pipes then?

smaller pipes are cheaper?

SWEI

Waaaaaaaaay cheaper. 3" screwed steel versus 1" PEX?

Gordy

It boils down to how gravity systems were designed. In those days pumps for these systems had not been invented yet, and the dead men relied on gravity for circulation. The large diameter piping was designed to facilitate the flow.

Fast forward to the invention of the circulator, and the implementation into these systems changed the game. Smaller diameter piping is now possible. Where the gravity piping exists why replace it if it is in good shape. That is why we can use smaller diameter piping for same size systems. And yes cost plays into it. Along with the labor of threading big pipe.

nicholas bonham-carter

The same hot water storage can be accomplished with a "Boiler Buddy" tank, if you are installing a new system, and need to lengthen the firing periods.--NBC

icesailor

bauer said:

Completely serious question/not being a smarta**...... Why aren't new rad systems designedly/installed with large pipes then?

One word: COST.

BA Radiators cost more money. It takes time to thread pipe. They used to use Sch. 40 threaded steel pipe for fire sprinkler systems. Now, it's all Sch. 10 with rolled groove victraulic couplings. The water collects where the grooves are inside the pipe and rust through the tissue paper pipe.

Progress, not perfection.

icesailor

Gordy said:

It boils down to how gravity systems were designed. In those days pumps for these systems had not been invented yet, and the dead men relied on gravity for circulation. The large diameter piping was designed to facilitate the flow.

Fast forward to the invention of the circulator, and the implementation into these systems changed the game. Smaller diameter piping is now possible. Where the gravity piping exists why replace it if it is in good shape. That is why we can use smaller diameter piping for same size systems. And yes cost plays into it. Along with the labor of threading big pipe.

And the development of cheap, high head/high volume circulators has lead to smaller and smaller pipes to do the job of what Mother Nature did without assistance. Only a 7 1/2 degree rise in temperature.

SWEI

icesailor said:

It takes time to thread pipe. They used to use Sch. 40 threaded steel pipe for fire sprinkler systems. Now, it's all Sch. 10 with rolled groove victraulic couplings. The water collects where the grooves are inside the pipe and rust through the tissue paper pipe.

CPVC fire pipe doesn't rot, and in fact allows you to use smaller branch lines as a result. Aquatherm sells a PP-R fire pipe system that's actually recyclable. Both are mostly for ordinary hazard areas unless covered.

icesailor

SWEI said:

icesailor said:

.

CPVC fire pipe doesn't rot, and in fact allows you to use smaller branch lines as a result. Aquatherm sells a PP-R fire pipe system that's actually recyclable. Both are mostly for ordinary hazard areas unless covered.

Aquatherm is the greatest thing that has come along since copper tube.

As far as using combustible materials like CPVC & PP, someone had to pay a lot of money to lobby and get it approved.

I can't wait for the reports of the private residences burning down and there was no water because there was no power to run the 10 GPM water pump.

You can't get people to change the dead batteries in their CO/Smoke Detectors, how you going to get them to keep up on air pressure in dry systems that are run in unconditioned space? A lot of effort to give some union sprinkler fitters a toe in the door.

You can't fix stupid.
You can't educate stupid.
You can't legislate against stupidity.

You CAN license it though.

SWEI

Lack of MIC is a huge deal in wet pipe systems. Anyone who has ever watched a steel piped fire sprinkler system being drained will not likely forget either the sight or the smell.

CPVC sprinkler pipe breaks down somewhere around 700°F IIRC.