Water radiator with condensing boiler?

[brucewayne]

the only thing i know is how to calculate edr, mine is 175. with 6 cast iron radiators
i just about had it researching this stuff, way too complicated. Now im not even sure if my radiators use water or steam. but if i turn the knob at the top, its a small skinny top, it leaks water when its turned on, and hot to the touch.


my heat exchanger is cracked, so i cant risk turning on long this winter.
i keep getting offers for condenser boilers. Are these contractors trying to scam me? isnt the water temp supposed to be higher to be efficient enough?
what would my minimum efficiency be in this case?

 

[Dana]

The red thing on the pipe coming out of the boiler is a pump, ergo it's hot water (not steam) for sure!

Placement of the expansion tank (blue, above the pump separated by a couple of tees) it pretty lousy. Ideally it would be on the intake side of the pump, which prevents cavitation on the pump, improving flow & longevity. See the location of the expansion tank relative to pump P1 in this diagram:

 

[Sponsor]

 

[BadgerBoilerMN]

Your atmospheric boiler has a potential efficiency of 85%. Any condensing boiler will start at 86% and have a potential of 95%.

Cast iron or radiators?

The heat load in a hydronic (hot water) heating system properly determines the size of the boiler with radiation used as a reference with the zones if any.

 

[Dana]

Morgan- this was covered (in painful detail ) on his other thread.

 

[BadgerBoilerMN]

Thanks

 

[brucewayne]

Morgan- this was covered (in painful detail ) on his other thread.

wait it was hard sometimes understand, painful ahh? so far, i only know as much a real estate agent, maybe less . Ive gotten alot of bad deals, im sure whatever i get now, will be better. Feel like i understand these boilers better, what to look for. and i thank this forum for that and you especially.

the only problem now is the plastic pipe.

so far, all contractors offered plastic pipe via chimney.....is there acceptable alternative instead of a side vent. Im sure the chimney is cheaper, cutting corners maybe.

 

[NY_Rob]

Actually, using the chimney for venting is more expensive than a side vent option.
You don't just use straight inexpensive PVC in the chimney, you install an approved chimney venting kit... which is several hundred dollars plus a couple of hours install time.

I'd rather have a chimney vent if possible because it gets the moisture rich exhaust away from the sides of the house where it can collect and freeze on the house during the winter. It also keeps the CO gasses away from doors & windows so there's no chance of it getting back into the house or being drawn back into the boiler which could cause combustion problems or in severe cases an explosion.

 

[Dana]

Plastic pipe the runs the full length of the chimney is a viable option, and a good one. As I understand it there are some locations where that is disallowed (on some theoretical basis that a future contractor will install a non-condensing burner in that flue or something), but if local contractors are proposing it, yours is probably not one of those juridictions where it is disallowed.

Venting through the roof using a new vent chase works too. The plastic vent diameter for these boilers are usually 3" at the boiler, but in most cases the vent run can be reduced to 2" if need be. That can often share a chase with a plumbing vent stack or an electrical chase. Review the venting requirments in the manual for Westinghouse badged version of the HTP-080W. (It's identical under the paint.) With that boiler if you reduce it to 2" you're limited to 50 feet of vent, which will still work with most homes, whereas if it's 3" the full run it's good for 100 feet.

 

[brucewayne]

ty i just found out via manual, boiler shouldnt be next to laundry, detergents cause damage. My washing machine is 5 feet away in same room.
i dont suppose its bad for todays boilers. its been this way for at least 30 years, with old cast iron gas boiler.

 

[BadgerBoilerMN]

There are no problems, as described, with a properly installed side-vent installation. It is the perfect solution and eliminates the long obsolete chimney with all of its' obvious faults e.g. convection of conditioned air, leaking and unnecessary penetrations of the house envelope and roof.

I have installed both vent and intake, and on occasion vent out the chimney with intake from the outside wall where the manufacturer allows.
There are some good arguments for this but few.

The truth is, most chimneys should be knocked down and will fall down on there own if not maintained.

 

[Dana]

The chimney will fall down even sooner if you keep venting the hot water heater into it after side-venting the boiler, eh?

If it serves no other purpose, (no fireplaces ?) demolishing it from the attic floor on up then air sealing over the top of the chimney & chase is usually the "right" thing to do. Gutting walls just to get rid of it only makes sense if you're doing a MAJOR rehab, and in some cases can buy you another square meter of living space.

The combustion air should be taken from the outdoors, away from clothes dryer or kitchen exhaust vents. Some chemicals such as fabric softeners can crud-up the flame sensors pretty quickly, and constant exposure to chlorine bleach in the combustion can damage burners and heat exchangers. With a sealed combustion boiler pulling ducted air from the outdoors (say, from above the roof top in the old chimney chase) there is no concern about mounting it near the laundry. The combustion air intake duct is also a 3-incher on most boilers, and can be reduced to 2" if necessary (with shorter maximum distances, as with the exhaust vent.)

If side vented it's important to keep both the intake and exhaust vents above the historical maximum snowpack depth, even if it involve a bit of a snorkel:

 

[NY_Rob]

^ That's a unique implementation of a side vent kit

 

[Dana]

Yup, but it definitely illustrates the "snorkel" aspect.

Here is another typical snow-snorkel vent example, but for lower snow depths than the prior:

The air intake has to be protected from slurping up falling or windblown precipitation, so it's usually directed downward, whereas the exhaust can be directed horizontally.

 

[NY_Rob]

I ended up going with a snorkel vent for my mod-con- pretty much right out of the HTP manual.
The only minor change was to add a down facing street elbow to each end of the intake Tee for protection. I cleared it with HTP support... they said it's absolutely fine.

 

[Leon82]

I can't imagine that top venting picture being printed in an install manual. Lol