forced air to hot water

adam9367

Hello, I’m a DIY’r and I’m doing a complete remodel of my house. I want to switch from forced air to hot water heat and I have a minimal amount of heating experience. However, I have a good working knowledge of plumbing and electric.



I have a two story, 3600 sq. foot house (1800 sq. ft) on each level. The first floor is sitting on a 4” concrete slab with the back half of the first floor under ground. The second floor is 2x4 construction with 3.5” insulation. Before buying all of the parts/boiler I was hoping I could get the opinion of a few professionals to make sure I have a good game plan. I attached some drawings to make the discussion easier.



My plan is to use a combination of Buderus radiators and Ultra-fin in floor heating (180 degree layout). I would like to have five zones: zone 1 for indirect water heat, zone 2 for the first floor, zone 3 for the second floor, zone 4 for the in-floor heat for the first bathroom and zone 5 for the in-floor heat for the second bathroom. For each radiator in zone 2 and zone 3 I plan on using ½ pex with home runs to the zone manifold. So here are my questions and thanks for the help in advance.



1. I used the slant-fin btu calculator to determine that my house needs 79,000 BTU; 56,000 for the first floor and 23,000 for the second floor. Does that seem reasonable that I could heat a 3600 sq ft. house with only 80,000 BTU?



2. I’m trying to determine if I should go with a high efficiency boiler or cast iron. Can someone please share pros/cons other than the obvious cost savings?



3. Can someone recommend a particular boiler? I have only used weil-mclain in the past (which I liked)



4. If I buy radiators that are rated for more BTU than the room calls for (aesthetic purposes) can I use thermostatic radiator valves on each of the radiators for regulating temperatures?



5. Would you recommend using a single circulator pump and zone valves or circulating pumps on each zone in place of zone valves?

Rich_49

Ultra Fin

 Do not use it , you will be making a HUGE mistake .  Suspended tube systems are for interior areas that need very little heat ,SOMETIMES.   The idea of Buderus Panel rads with TRVs is a good one , why not use them everywhere ? Only the areas that require heat will get it , you will be extensively zoned without wires , and you will save a ton of fuel money .  I would run them all as homeruns from a central manifold and use a variable speed ECM circ capable of handling the volume and pressure required if they are all calling at once , unlikely . As far as boilers go , there are many good ones out there . If you want to use a condensing boiler you will have to upsize the Panel rads a bit to insure the High efficiency boiler is getting low enough return water temps for you to receive the rated efficiencies for a good portion of time every year . I would be inclined if budget is a constraint to go with an 85% boiler , a 3 way Taco I series mixing valve with outdoor reset and boiler protection and sit back and enjoy the comfort and savings . Just my .02 .

adam9367

mixing valve with outdoor reset

I like the idea of using the standard cast iron boiler but I wouldn't know how to configure the mixing valve with the outdoor reset/boiler protection. I heard they can be very trick to configure correctly. Do you offer consulting?



I wanted to use the ultra-fin to warm the ceramic tile floor. (I hate walking on a cold floor.) I was also going to install a radiator to supplement if the in-floor wasn't sufficient.



How would I determine how big of a circulator I need for the zoned manifolds?



Thanks for the feedback!

Rich_49

Ultra Fin

is not the way to go . Please tell me the exact situation you are looking at and how you intend to install the Ultra Fin and maybe we can tell you about better alternatives .