She's A Brick House and Cold

FeelingColdColdCold

What's the right boiler? 1930 brick house 2700sf with uninsulated walls and 1930s windows. 4" of insulation in attic. Steam converted years ago to hot water with 6 foot+ cast iron radiator in every room all on 1 zone. Was told making another zone would be a fortune in new plumbing. Plumber reco was a Knight KHN155 - same BTUs as the Reagan era Burnham currently. Seems overkill. No heat loss calculation done but insists that the Lochinvar will just step down to accommodate if capacity is more than needed, will not short cycle, and will insure warmth on bitter cold days. House never comfortable in winter as interior walls are 10 degrees colder than tstat.

Lance

At least the right question is being asked. Proper application is a must. In the 30's air infiltration was not a concern. Brick did make for less infiltration but holes for mechanical, electrical still were not sealed. A heat loss J-calculation is a must. Yes one can guess the size and put in a step fire boiler, and all will be better, but why take the chance and waste money when the consequences can be too expensive? 4" insulation in the attic was below the minimum in the 60's. R-11 is at least 6". We want R38 today. But the real issue can be infiltration. It has been shown to be more important if it is bad. What good is insulation when the equivalent of leaving the front door open is still leaking heat out? A blower door pressure test would be recommended to see how bad it is.
We can pump a lot of heat in, but why should we if we can reduce the load? All this should be considered to make the best plan to build it right. But I can put this in perspective and say yes this is a decent plan, yes if the old did the job, staged firing and limit controls especially an outdoor reset control can make a decent job. But consider the life cycle plan for the building. If you want to keep it another 30 years, it is still cheaper to improve the building than build another house more efficient.

nicholas bonham-carter

Does the present boiler have a problem requiring replacement? Is the boiler correctly installed? That boiler may be 3 times oversized for the heatloss! Does it short-cycle?
Are you using temperature setbacks? A lower constant temperature will be more comfortable, and will allow the walls to warm up.
What purpose would the additional zone serve?
Download the SlantFin heat loss app, and see what the house needs in terms of BTU’s.
Lance is right about tightening up the envelope, and increasing the insulation, much of which you may be able to do yourself. Combination storm windows will cut down on the heatloss from the windows.—NBC

unclejohn

She might be a brick house but is she Mighty Mighty. Thats the question.

Canucker

unclejohn said:

She might be a brick house but is she Mighty Mighty. Thats the question.

Maybe it's cold because it's built like it's in the Amazon? Letting the insulation all hang out? (Hijack done)

Jamie Hall

As has been noted, the first step is a heat loss -- and tightening up the envelope (there are several excellent, inexpensive storm window options, by the way -- combination storms are one, but "innerglass" is another).

I am a little concerned, however, by your mention that this was converted from steam. The radiation may have been oversize for steam -- probably was -- but may be seriously undersized for hot water, which can only deliver about 70% of the heat that steam does for a given radiator.

Gordy

@Jamie Hall brings up a valid point, and concern. As he mentioned the radiation was sized for steam, and higher delivery temps. Throwing in a new boiler does not solve that issue.

A heatloss, and an edr survey of the existing radiation based on hot water btu output is in order here.

EBEBRATT-Ed

Back to the basics. Heat loss calculation and radiation sizing & pipe sizing after flow is determined.

Everyone wants answers, but they won't start at the begining

leonz

If the boiler is not leaking why change it out???????????????

If he is not willing to do a heat loss calculation find another contractor to fix the problems with the current boiler IF ANY and or tune up current boiler and then go from there to button up your home with window seal kits etc. and get through the winter with a lot of caulk and foam sealant in the obvious air leaks.

You have a lot of water in those radiators that can help with heating at a lower water temperature(if desired)once you have a handle on the air leaks.

nicholas bonham-carter

As Jaimie has pointed out, a radiation survey needs to be done to find out how much heat the radiators can supply with hot water, which is cooler than steam. That could be the limiting factor, and a new boiler will not overcome that.
In the meantime, keep a constant temperature, and record the interior/exterior temperature with an indoor/outdoor thermometer which remembers the highs, and lows.—NBC
One more thought: some old two-pipe vapor systems, which were the best and most comfortable, had orifices in the radiators to control the maximum steam inflow-maybe those are still in the valves, and will need to be dealt with.

Gordy

NOt really if once steam the edr is 210 btus sf.

Hot water with an AWT of 170 degrees comes to an edr of 150 btus sf.

The rads were sized for the output of steam, so a 40 btu per sf radiation deficit results from the conversion.

Probably why the brick house is cold.

This is why an EDR survey should be part of the heatloss audit. You never know what untrained professional thought they knew what they were doing.

leonz

I forgot to add this the other day but please keep in mind that the more you seal up the home the less the radiators will shed heat as there will be less air movement in the home and it will
be colder.

Rich_49

leonz said:

I forgot to add this the other day but please keep in mind that the more you seal up the home the less the radiators will shed heat as there will be less air movement in the home and it will
be colder.

Keep studying Leonz . Someday you'll put all the pieces together .

The more you seal the building the less infiltration you have , the less infiltration , the lower the heat loss , the lower the heat loss , the lower the temps required are . R value makes much less a difference in heat load calcs than does ACH .

EBEBRATT-Ed

@leonz If what you said is true we should all open all our windows to increase the airflow and enjoy the heat

Steamhead

With radiators that big, is it possible this was originally a gravity hot-water system?

Take a picture of a radiator and post it here- also the piping in the basement. Let's have a look.

Brewbeer

Since brick is such a poor insulator, the brick is always going to be cold when it's cold out. Four inches of brick has an R value of 0.8. A 12-inch thick wall would be less than R-3, and five times lower than a typical insulated wood frame wall assembly.

@FeelingColdColdCold If you want the wall temperature to be close to the thermostat setting, you will need to insulate them.

I wonder if the conversion from steam to mod-con hot water was an attempt to reduce heating bills - which must be astronomical in a 2,700 sq. ft. house that has R-3 walls.

Getting back to your original question "What's the right boiler ?", a steam boiler would probably provide greater comfort when it's chilly outside and the walls are cold.

Gordy

Steamhead said:

With radiators that big, is it possible this was originally a gravity hot-water system?

Take a picture of a radiator and post it here- also the piping in the basement. Let's have a look.

Op stated it was steam converted years ago to hot water, But you have a point.

Steamhead

Gordy said:

Op stated it was steam converted years ago to hot water, But you have a point.

Never hurts to check.

leonz

Speaking from my experience and having grown up with steam heat and owning a converted school house home with hot water baseboard which I hate that is now heated with a Keystoker KAA-4-1 coal stoker boiler.

As a layperson I think your better off with converting back to steam heat as the operating pressures are lower and returning steam heat to the home will be more efficient and the new boilers are much more efficient.

From what I have seen of videos on you tube some folks are using the heavy grade refrigerant grade soft copper pipe that comes in rolls to feed steam to panel radiators with the TRV controls.

Perhaps you should look at replacing the basement mains with hard copper pipe, and then go about cleaning the radiators and replacing the radiator valves and perhaps adding a panel radiator here and there to deliver steam heat by using refrigerant grade soft copper pipe to the existing radiators from the new mains??

As a first step in the coming summer months-
perhaps servicing the boiler burner and the boiler controls and just doing a good cleaning the old horizontal mains with the good boiler tube brushes from Mcmaster Carr and adding unions at the same time where needed and making use of the heavy refrigerant grade soft copper to deliver the steam to the radiators from the old cleaned steam mains using new threaded Tees would be worth considering.

FWIW:
We had a very small open flame gas fired steam boiler the size of a typewriter table that heated our huge apartment above my parents business with single pipe steam.

Gordy

Mini tube steam is what you are referring to.

jumper

Were I repiping home for steam,I'd try to put main in attic and then run individual soft copper pipes to each terminal. Leave some bend in those pipes to deal with thermal expansion.

leonz

Hello jumper,

In using the attic; would or should the soft copper still be positioned to rise from the main at a 30 or 45 degree angle and then drop to each radiator in the top tapping to keep dry steam coming to the radiator and then having the bottom tapping for the return pipe to the boiler sump?

RomanGK_26986764589

Probably a very silly question but could one run a hot water system at temps higher than 180 degrees? Maybe 215-220? The water won't boil since it's under 15 psi of pressure?

Jamie Hall

RomanGK_26986764589 said:

Probably a very silly question but could one run a hot water system at temps higher than 180 degrees? Maybe 215-220? The water won't boil since it's under 15 psi of pressure?

Not a silly question at all. It would work just fine; your truck's radiator does, after all. So long as you kept the pressure at the highest point well above the boiling point -- 5 to 10 psi above (so 25 psi running 220) you'd not have a problem. From that standpoint.

However... why? For one thing, you'd have the probability of leaks in the radiators. For another, you'd certainly want really good safety valves. Valves. Plural. I you were to suddenly release the pressure when you were above atmospheric, most or all of the water in the system would convert to steam immediately (a volume factor of about 1700, if I recall) which would result in very loud noises and falling objects. Not recommended.

Robert_25

RomanGK_26986764589 said:

Probably a very silly question but could one run a hot water system at temps higher than 180 degrees? Maybe 215-220? The water won't boil since it's under 15 psi of pressure?

You certainly could, and sizing systems for 210F water was not uncommon at all when builders were trying to minimize the amount of radiation in each house. I am pretty sure my old IBR manual for hot water systems goes up to 215F for the sizing worksheet of hot water radiation.

Back to the original poster - the first thing I would do is see if there is even enough radiation to carry the load. if the system used to be steam, and it was converted to hot water without any insulation improvements to the house, you very likely do not have enough radiation to do the job with water temperatures that most us are used to running.

Gordy

My god just convert back to steam.....

I think the OP has been scared away.

leonz

I hope he has not been scared away, I wonder what is going on with this heating system now.

EBEBRATT-Ed

Probably put scorched air in