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Patrick Presti
Heating Suggestions for Second Floor Addition
Patrick Presti

Hi Guys,

I recently added a second floor addition to my cape on Long Island. I am starting to think about heating for the second floor. I am considering hot water radiant heat. Is there any preferred method of radiant heat such as above or below the sub-floor? I will have access to either side of the sub-floor. Any feedback would be greatly appreciated.

Thanks,

Pat

NashuaTech
Re: Heating Suggestions for Second Floor Addition
NashuaTech

Pat,

What type of heat do you have on the 1st floor now??? You would have to have an existing radiant or hw heating on the 1st floor, with a boiler in the cellar/utility room if you plan to easily expand the same system to the 2nd floor.

Have you considered expanding your existing system to the upstairs section???

Sub-floor radiant is usually much more expensive to install than, for example HW baseboard or other types of heating.

Patrick Presti
Re: Heating Suggestions for Second Floor Addition
Patrick Presti
NashuaTech wrote:

Pat,

What type of heat do you have on the 1st floor now??? You would have to have an existing radiant or hw heating on the 1st floor, with a boiler in the cellar/utility room if you plan to easily expand the same system to the 2nd floor.

Have you considered expanding your existing system to the upstairs section???

Sub-floor radiant is usually much more expensive to install than, for example HW baseboard or other types of heating.

My current first floor has a gas fired boiler with hot water recessed radiators in the walls. I plan on gutting the first floor and will be replacing that heating system too...

Thoughts?

Pat

MichaelInOr
Re: Heating Suggestions for Second Floor Addition
MichaelInOr

Run the tubing on the top of the sub floor and flood with a self leveling cement. The cement acts as a huge heat sink that comes up to temperature then radiates the heat slowly over several hours. Very comfortable and quite efficient!

Put each room on its own zone. We have a couple rooms that we don't use often and having them on their own zone allows us to only heat the room when we use it. I have electric floor heat but the principal is the same. I wish I had gas fired hydronic floor heat!

Pelton
Re: Heating Suggestions for Second Floor Addition
Pelton

Patrick,

I would agree with Nashua Tech in that you should 1st consider hot water baseboard for your addition (and perhaps for the refit of your 1st floor unit, when the time comes); see bgm supply site below for photos of standard baseboards.

It is also very easy to install 1 or 2 zone valves on the existing near-boiler piping; this would enable you to use your existing boiler/heating system to heat both the 1st & 2nd floors using separate T-stats for the 1st & 2nd floors, using the same boiler.

How do you now heat your domestic hot water (for showers, shaving, dishwashing, etc.)??? If you don't have one already, consider installing a 30 gal or 40 gal INDIRECT HOT WATER HEATER---these run off your present boiler as a separate zone & represent the least expensive way of heating your DHW---you'll never run out of HW with one of these long-lasting units!

Baseboard gives a good heat response. is attractive in appearance, & is a dream for the DIYr to buy at low cost locally & easily installed; in addition it is widely available locally at Home Depot, Lowe's & numerous other building materials dealers.

I notice by your previous posts that you seem to be doing most or nearly all your remodeling projects yourself as diy projects, and this is a good thing---more the reason I think you should strongly consider hydronic baseboard as the best way to update your existing heating system & expand it to the upper floor.

This would require soldering skills & tools if you decide to go with copper tubing & fittings; if you decide on PEX (plastic tubing) you would have to learn to select the right brand & application of PEX, along with the needed mastic or crimping tools to attach the PEX to the various fittings---follow the You Tube videos for info on selecting the correct tools and supplies for this aspect of the project.

You would have to calculate the winter heat loss you are experiencing especially on your 2nd floor, so that you install an adequate amount of baseboard to replace the amount of cold air that exists in the 2nd floor apt. as well as designing the amount of baseboard installed for the coldest days of the winter heating system---Google "Simple Heat Loss Calculators" to get an idea of how much heat is being lost thru the 2nd floor exterior walls & windows to the outdoors each hour, according to the square footage (length X width of the 2nd floor apt.), the height of the ceilings, the square footage of all the windows, the insulation (if any) in the exterior walls, the type of material used to build the exterior walls, etc.

First take a look at all the 2nd floor windows to see that they are all (hopefully) double-pane, relatively new, & without any cracked or loose panes of glass---any old single-pane windows should especially be examined for age, as well as any loose-fitting panes, etc., & should be replaced if not absolutely tight---extensive heat loss & fuel bills result from old, loose-fitting windows; likewise, determine if the exterior walls of the 2nd floor apt. have blown-in insulation, or had been insulated in previous years---if not, it is money well-spent to have insulation blown in, which is money well-spent & saved on future heating bills.

Google "Modern Hydronic Heating-Google Books" to get access to an outstanding book on hot water heating design & installation systems---most needed info & topics is available at this site without having to spend $300 for the book!

Also Google "How to create zones in a hot-water heating system video by Richard Trethewey"

You should also read a previous TOH post that was posted on this topic on 10-27-15 in the Plumbing section entitled "Help Needed Amount of Baseboard and Circulator Pump Size" by Greggdiy.

Finally, while at the You Tube site, scroll down & click onto all the other sites there that have to do with hot water heating topics.

www.bgmsupply.com/baseboard-radiation.php
https://www.youtube.com/watch?v=Q4_Oshg1XXo

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