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Newbie Radiant Install

I'm set on installing a radiant heating system in an old house (i.e., some, but poor insulation -- lots of heat loss). LP tanks.
From inside the basement, I have open access to the 2x10 16" OC floor joists under the 1st floor.
I understand Uponor pex and heat plates are very good, and I understand (I think) the looping process and runs under 300' and insulation under (lower) the pex/plates.
I understand a boiler is much smarter than a hot water heater (even a tankless), and I'll need an expansion tank, pump, gauges, sensors, drain/fill spigot.
The first floor is about 22x38, and I think 1 zone would be just fine. I'm having a very difficult time doing a heat loss analysis because the first floor extends past the borders of the basement -- that is, there are rooms that are supported by piers outside the footprint of the basement. I was going to just ignore those for now, and leave those for additional zones.
But that's about as far as I got (not that I've got that down pat).
I'm trying to understand the piping at the boiler, and reading lots of posts here and getting more and more lost. Specifically, using the straight through vs. bull (Tee) side of a tee, mixing valves and control circuitry is not something I have any grasp of.
Anyone have any advice on how to proceed? It's January and it's cold and the electric heat is working very hard and costing me a lot of money.
Thank you!
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Comments
Where in NY are you located?
We just wrapped up a full house radiant project in Queensbury (Lake George Area).
Lic #12683
Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
Marketing & Operations: Dawn Drescher
201.499.0223
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I'm in Sullivan County, NY. Basement is 22x38 (836 sq-ft) but first floor is ~$1,700 sq ft (irregular shaped bump outs on all sides, constructed at various times over the past 60 years).
The exterior of the first floor has varying levels of insulation.
There is a 2nd and 3rd floor also, each 836 sq ft. But, the house is renovated, so I'd like to install the radiant just under the first floor (and probably just under the the main (over basement) area.
Thanks!
Lic #12683
Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
Marketing & Operations: Dawn Drescher
201.499.0223
Follow us on Facebook.
Check us out on Instagram: creative_solutions519
Lic #12683
Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
Marketing & Operations: Dawn Drescher
201.499.0223
Follow us on Facebook.
Check us out on Instagram: creative_solutions519
Lic #12683
Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
Marketing & Operations: Dawn Drescher
201.499.0223
Follow us on Facebook.
Check us out on Instagram: creative_solutions519
The job in Lake George we just did two of the rooms required supplemental heat besides the radiant so we installed panel radiators along with radiant in those rooms.
Lic #12683
Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
Marketing & Operations: Dawn Drescher
201.499.0223
Follow us on Facebook.
Check us out on Instagram: creative_solutions519
A few pics of the underfloor would help. If there are a lot of nails protruding it will not be an easy plate installation.
You may end up with a hybrid radiant and panel radiator system.
There are some assumptions that need to be made when calculating an existing building, someone that does load calcs knows how to estimate those unknowns.
trainer for Caleffi NA
The magic is in hydronics, and hydronics is in me
What can I do if I don't know those numbers? I know lots of the walls have a single layer of paper backed fiberglass batting, and the windows are just cheap big box store windows.
If we guess, and then oversize the boiler but use a modulating one, use 300' pex runs, would that work?
I wouldn’t rely on the just the maximum 300’ loop length method, we rely on a system design and play around with numbers once that’s all been squared away.
Lic #12683
Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
Marketing & Operations: Dawn Drescher
201.499.0223
Follow us on Facebook.
Check us out on Instagram: creative_solutions519
It was easy and worked great. Just wear eye protection and have some water in windex bottles, just in case.
It takes time and experience to accurately do what you want and people get paid to figure out the things you want to know. This is a site to help and and people do get lots of help on here, but spilling the beans about every aspect doesn't help the business side of things. Not that everything is about business all of the time.
Keep in mind I'm new here but that is my opinion. I'm sure @ChrisJ will comment and tell me I'm way out of line, lol.
My local distributor has generously offered to the analysis, but unless I can provide the data, he would be just guessing.
I do really want to learn this stuff.
Lic #12683
Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
Marketing & Operations: Dawn Drescher
201.499.0223
Follow us on Facebook.
Check us out on Instagram: creative_solutions519
I used the slant/fin (as best I could).
I made room 1 the area over the basement and room 2 is one additional area/extension and room 3 is another additional area/extension.
Here's what I got (and I probably erred on the high side of the heat loss):
Floor 1 TOTAL FLOOR BTUs: 20820
Room 3 SELECTED BASEBOARD: BTUs: 7524
Room 2 SELECTED BASEBOARD: BTUs: 1541
Room 1 SELECTED BASEBOARD: BTUs: 11755
Does that mean that room 1 (836 sq-ft with 11,755 BTU/HR loss) needs 14 BTU/Sq-ft? And if so, that's not too difficult to achieve?
If my calculations are in the ballpark, and I eventually would like all 3 "rooms" heated, then I'll need a boiler/heater that can provide 21000btu/ht, which is the net amount after taking into account boiler efficiency, right?
And, a modulating one (Lochinvar 10:1?) means that I can't go very wrong getting one that can handle 50000BTU/hr, right?
I'm also interested in the possibility of a combi to produce DHW.
Okay, fire away -- how many errors have I made (;-)?
Load calcs are only as accurate as the data that's entered.
If need be, post the square footage of your walls, Windows, doors, exposed ceilings and floors with their respective construction data, as well as your locale, and we'll see how close your numbers look.
You can choose to do what you want, but you cannot choose the consequences.
I would stay away from a combi unit and go with a boiler and indirect tank.
Lic #12683
Co-Owners: Fred Drescher, Jr & Eliezer "Ezzy" Travis
Marketing & Operations: Dawn Drescher
201.499.0223
Follow us on Facebook.
Check us out on Instagram: creative_solutions519
Room Height (ft) 9
Room Length (ft) 38
Room Width (ft) 22
Door (sq ft) (Add manually OR click arrow to calculate) 3
Doors Factor (Add manually OR click arrow to calculate) 0.75
Glass (sq ft) (Add manually OR click arrow to calculate) 150
Glass Factor (Add manually OR click arrow to calculate) 0.65
Exposed Wall Length (ft) 100
Exposed Wall Factor (Add manually OR click arrow to calculate) 0.1
Cold Partition Length (ft) 0
Cold Partition Factor (Add manually OR click arrow to calculate) 0
Ceiling Factor (Add manually OR click arrow to calculate) 0
Floor Factor (Add manually OR click arrow to calculate) 0
Infiltration Factor (Add manually OR click arrow to calculate) 0
Indoor Temperature (F) 72
Outdoor Temperature (F) 5
Room Height (ft) 8
Room Length (ft) 8
Room Width (ft) 10
Door (sq ft) (Add manually OR click arrow to calculate) 21
Doors Factor (Add manually OR click arrow to calculate) 0.75
Glass (sq ft) (Add manually OR click arrow to calculate) 40
Glass Factor (Add manually OR click arrow to calculate) 0.65
Exposed Wall Length (ft) 20
Exposed Wall Factor (Add manually OR click arrow to calculate) 1
Cold Partition Length (ft) 0
Cold Partition Factor (Add manually OR click arrow to calculate) 0
Ceiling Factor (Add manually OR click arrow to calculate) 0.1
Floor Factor (Add manually OR click arrow to calculate) 0
4064 BTUH
Room Length (ft) 40
Room Width (ft) 16
Door (sq ft) (Add manually OR click arrow to calculate) 44
Doors Factor (Add manually OR click arrow to calculate) 0.75
Glass (sq ft) (Add manually OR click arrow to calculate) 200
Glass Factor (Add manually OR click arrow to calculate) 0.65
Exposed Wall Length (ft) 20
Exposed Wall Factor (Add manually OR click arrow to calculate) 0.1
Cold Partition Length (ft) 0
Cold Partition Factor (Add manually OR click arrow to calculate) 0
Ceiling Factor (Add manually OR click arrow to calculate) 0.1
Floor Factor (Add manually OR click arrow to calculate) 0
indoor 72
outdoor 5
13641 BTUH
18097 BTUH
Total:
35802 BTU/H
I don't know how to account for window or door infiltration.
Basement is not heated -- mineral rool between joists.
Thank you for pointing these out.
Here's the long and short of it: it's generally recommended to keep the supply water temp at 120* or less for wood floors. Using good aluminum heat transfer plates, you'll get about 20 btus per square foot output from a radiant floor at 120* SWT, depending upon your floor covering. This was proven by a scientific study at VA Tech about a dozen years back and we have means of calculating it now too.
So, the output of a radiant floor would fall short of heating the house from the lower 20's and below. If you choose to door the floor, you're gonna need supplemental heat when it's colder outside. Panel rad's or low temp baseboards are a couple of options.
You can choose to do what you want, but you cannot choose the consequences.
As far as insulation in the joist bay under the pex, this is what I do. I use a polyurathane 1" solid insulation board with the foil side up against the pex which creates about a 1" space between the insulation and the sub-floor and then put fibre glass insulation under the insulation board. This spreads the heat pattern over the whole joist bay and not just where the plates are and it really prevents backloss.
You really have heat energy resistance thru the subfloor and flooring. Spreading the heat across the whole joist bay would increase the radiation into the room thru the flooring. Am I being redundant?
The 1" foil face up rigid insulation is a great idea.
I can't say I understand exactly what happens to the heat emitted by the pex/plates as it passes through the flooring, but my basic research shows the plywood-oak combination is about an R 1.5. Not that that fully explains (to me) what happens to the energy emitted by the pex/plates, but I understand that directing/reflecting as much as possible upward is best.
I would not worry as much about the foil, it will dust over in short order and not add much value. It needs to be clean and shiney to do any reflecting. I'd spend more money on r-value under the installation, at the very least 6" of batts.
The end of the joist bay, the rim joist is the biggest concern. I'd spray foam and put blocks of foam board there. You have both temperature and infiltration concerns at rim joists, a high heat loss detail.
trainer for Caleffi NA
The magic is in hydronics, and hydronics is in me
I put 1-1/2" Rmax or Celotex against the rim joist and blocking.