In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Scott's radiant heating project
I’m designing and installing a wall radiator hydronic system in my home and am hoping to get some advice along the way from the pros on this forum. I have an extensive background in kitchen/bath remodeling and have adequate plumbing skills. I’ve done a considerable amount of reading on the subject of hydronics, and recently purchased “Modern Hydronic Heating” by Siegenthaler as a reference. A good friend with 20 years experience installing hydronic systems is helping with the project. The area where I need the most help is system design and pipe sizing.
My home is 1,550 sq feet, single story SOG with a T&G built up roof. I live in the San Francisco Bay Area (warm summers, mild winters) and my house is very well insulated including dual glaze windows. In short, my heating requirements are minimal. I’ve done a preliminary heat los calc using Slant Fin’s Heat Loss Explorer software. I plan to attempt a more thorough heat loss calc using the MHH book as a reference.
I have a 1960’s AO Smith Copper boiler that was installed when the house was built and is still running strong. Here’s the rub: the boiler has 80,000 BTU output @180 degrees, far in excess of my needs. I'm fully aware that using this oversized and inefficient boiler will result in frequent short-cycling. I also understand that frequent short-cycling will increase my fuel consumption. I’m selling this house in 18 months and am not interested in spending $5K + to upgrade the boiler at this time unless presented with evidence that keeping the over-sized boiler will cost more than the extra few hundred dollars/year in natural gas expense. It has been suggested that I install a buffer tank to minimize the short-cycling. I would be open to any suggestions on how to improve efficiency using this boiler.
The preliminary plan is a simple no-manifold 2 loop system (one loop for the front rooms, another loop for rear bedrooms). I’m installing wall mount Runtal rads with TRV’s. I’m not interested in series looping, and am deciding between parallel direct return or reverse return piping. Since I have no crawl space, all piping will have visible exposure, either over the roof or under the eaves (with pipe insulation of course). I'm leaning toward direct return to minimize the copper.
I’ll be posting more after I've had time to review the MHH book, which will no doubt raise more questions.