When is a high efficiency condensing boiler not a high efficiency condensing boiler?

Post by **Rob R.** » Thu. Jan. 14, 2021 7:23 pm

That is a big project Larry. Radiant heat does not transfer well through carpet, and I don't see much benefit to using it in the bedrooms and hallways anyway. I think you would enjoy it the most in the bathrooms and kitchen, followed by the dining and living room.

The amount of pex you need is based on the spacing, which is determined by the heat loss of the room and flooring material.

lsayre · Post by **lsayre** » Thu. Jan. 14, 2021 7:27 pm

Rob R. wrote: ↑
Thu. Jan. 14, 2021 7:23 pm
That is a big project Larry. Radiant heat does not transfer well through carpet, and I don't see much benefit to using it in the bedrooms and hallways anyway. I think you would enjoy it the most in the bathrooms and kitchen, followed by the dining and living room.

The amount of pex you need is based on the spacing, which is determined by the heat loss of the room and flooring material.

Currently only 3 bedrooms have carpet.

Would we have the capability of each room being on its own thermostat with under-floor radiant?

lsayre · Post by **lsayre** » Thu. Jan. 14, 2021 8:10 pm

I'm toning down my need to 7 x 300 foot under-floor radiant zones. If each foot of 1/2" PEX has the potential to emit 22 BTUH, that would put 7 x 300 x 22 = 46,200 maximum BTUH into upstairs heating. For comparison, our old 13.5 KW resistance boiler had 46,062 BTUH output.

For baseboards this comes to 46,200/81 = 570 BTUH per foot of baseboard. For my current baseboards this requires 170 degree average water temperature, and for Haydon 958-2's it would require 150 degree average water temperature.

I think simply going with the Haydon HWB's and a kickspace heater in the kitchen would be much cheaper and easier overall. It won't give us the potential for 100% condensing conditions such as under-floor radiant would likely do, but it may switch my current 20/80 condensing situation (as for the 'Inverse Pareto Principle') into more of an 80/20 condensing situation.

McGiever · Post by **McGiever** » Fri. Jan. 15, 2021 10:19 am

At some point after pondering on numbers readily available you may want to consult with a professional radiant designer...not an installer.

Post by **Rob R.** » Fri. Jan. 15, 2021 1:06 pm

lsayre wrote: ↑
Thu. Jan. 14, 2021 8:10 pm
I think simply going with the Haydon HWB's and a kickspace heater in the kitchen would be much cheaper and easier overall.

The new baseboards and toe kick heater will definitely do the job, you just get a little fan noise instead of warm floors. It is always a compromise of features and cost.

There are also heaters that are made to be recessed in the floor. Typically they are placed in front of big windows or sliding doors.

https://www.slantfin.com/products/hydronic-floor-box/

Berlin · Post by **Berlin** » Fri. Jan. 15, 2021 3:22 pm

did you look at the panel radiators? they give heat through radiation and convection, they mount on the wall, and are attractive. I've sold a ton of them. much better than baseboard and, sized properly, they allow lower water temps. They're also fairly reasonable.

lsayre · Post by **lsayre** » Fri. Jan. 15, 2021 6:54 pm

Berlin wrote: ↑
Fri. Jan. 15, 2021 3:22 pm
did you look at the panel radiators? they give heat through radiation and convection, they mount on the wall, and are attractive. I've sold a ton of them. much better than baseboard and, sized properly, they allow lower water temps. They're also fairly reasonable.

Is there a brand you recommend?

Berlin · Post by **Berlin** » Fri. Jan. 15, 2021 10:30 pm

I like the myson units with the thermostatic control. The importer is out of vermont, but, most supply houses in the northeast can get them.

lsayre · Post by **lsayre** » Sat. Jan. 16, 2021 9:20 am

Berlin wrote: ↑
Fri. Jan. 15, 2021 10:30 pm
I like the myson units with the thermostatic control. The importer is out of vermont, but, most supply houses in the northeast can get them.

The panel radiators idea (which I actually liked) is out, as my wife doesn't like them. She is OK with Haydon 958-2 baseboards throughout, plus a single toe kick in the remodeled kitchen, or with under-floor radiant for the entire upstairs, with Haydon HWB's for only the basement and garage zones.

lsayre · Post by **lsayre** » Thu. Feb. 18, 2021 5:43 am

Since I've tracked my NG boilers usage performance vs. HDD's from the day of its install, I have just computed that its overall "system" efficiency with regard to HDD's is (to date) 74.7% via using the same all electric heating baseline data originally used to conclude that my S-130 Coal Gun was 70.7% overall efficient with regard to HDD's. I'm finding (as has been discussed above) that there is a gross mismatch between my old "high mass philosophy" hot water baseboards and the modern day ultra-low mass boiler design philosophy. And I believe efficiency would rise quite noticeably (due to condensing criteria) if I replaced my baseboards with newer "high output" baseboards that are advertised to be a match for the low mass boilers of today which utilize outdoor reset, and which deliver as much heat with 150 degree water as do my current baseboards with 170 degree water.

Where the NG boiler is really proving to be on the winning side has been in its efficiency and cost to provide DHW as opposed to either a standard old electric HWT or the coil in the Coal Gun. From June through August when the only demand upon the NG boiler was to provide for DHW the efficiency of "on demand" vs. sitting loss incurred for electricity or fire maintaining coal consumption loss for the S-130 gave me well over 100% DHW BTU efficiency "by comparison" to either of these two baselines. This is not to imply that actual DHW efficiency is greater than 100%, but rather only that relative to coal or resistance electricity there is an apparent "ratio based" (or relative) efficiency of greater than 100%.

lsayre · Post by **lsayre** » Thu. Feb. 18, 2021 6:56 am

Relative fuel cost comparison from April 1st, 2020 through yesterday:

NG = $1,114
Coal ~= $1,003
Electricity ~= $2,170

Qtown1835 · Post by **Qtown1835** » Thu. Feb. 18, 2021 10:42 am

lsayre wrote: ↑
Thu. Feb. 18, 2021 6:56 am
Relative fuel cost comparison from April 1st, 2020 through yesterday:

NG = $1,114
Coal ~= $1,003
Electricity ~= $2,170

Extra $111 for no moving coal, ash and dust. I'd say that's a win

Keepaeyeonit · Post by **Keepaeyeonit** » Sat. Feb. 20, 2021 7:47 am

Qtown1835 wrote: ↑
Thu. Feb. 18, 2021 10:42 am
Extra $111 for no moving coal, ash and dust. I'd say that's a win

100% on that one!

But you need to revisit this a year from now Larry and see if the cost different is still that close.

lsayre · Post by **lsayre** » Sat. Feb. 20, 2021 9:00 am

Keepaeyeonit wrote: ↑
Sat. Feb. 20, 2021 7:47 am
100% on that one! But you need to revisit this a year from now Larry and see if the cost different is still that close.

I will be tracking it. Due to certain recent events I expect the price of NG to rise. What is the outlook for anthracite?

I will say however that I'm paying quite a bit more for NG than my daughter who lives only about 4 miles north of me in Medina, OH. She is supplied by a major, and may also be benefiting from city negotiated pricing, and I'm buying from a tiny rural Co-Op that specializes in bringing NG to users the majors wouldn't likely ever want to bother with. The co-op did run NG down our street at no cost to anyone, but for this they intend to recover their cost by jacking up the price of the NG. This is supposed to be the case for only the first few years, but (from reading various blog posts from other co-op members) I'm skeptical as to whether or not that will pan out to be truthful of them. Particularly since so far I appear to be the only one on our mile long street who has switched to NG. Everyone else is on electricity or propane. Hopefully those on electricity have heat pumps. An immediate neighbor to me just got done switching over to heat pump electric a year before the NG line went in, and now he is not all that happy about the 'changed' situation.

Keepaeyeonit · Post by **Keepaeyeonit** » Sat. Feb. 20, 2021 9:27 am

I will be watching it but I would suspect with the rise in fuel the coal will rise also, this is what I paid November of last year.

2400# of bagged Blaschak stove for ($329.00) $350.28 OTD
from Cherry Valley stove and 2700# of bulk Lehigh nut for ($227/ton) $317.94 OTD from Boslers.