Multi-zoned radiant floor/baseboard heat

[whizeazz]

Hello All! I am currently replacing my heating system. I plan to install a 4 zone radiant heat and domestic hot water off of an unpurchsed tankless water heater. basically i plan to run 2 zones of pex radiant floor heat on the first floor (1300sf) and then baseboard in the master bedroom (entire 2nd floor 600 sf) and also baseboard in the soon to be half finished basement; 2 rooms, laundry (150sf) and office (250sf)
As far as installing the PEX tubing, baseboard, and water heater, I think i'm pretty good. I am getting a little over my head when it comes to the different pumps/controllers used for the different zones. I am told that all loops in each zone need to be almost the same size. I don't really see why there are so many different sized pumps. So....first round of questions:

What water heater should I get? I am looking at Takagi T-D2-IN but fear it may be an overkill

What pumps should I get? I have been looking at the Taco pumps, but don't know what size to get. Different for each zone size? i would assume

What controls the pumps. I know obviously a thermostat, but saw something about a zone relay controller or something.

And last for now; I have been doing a lot of research, and i have seen a few different set ups. most are similar, but some call for an expansion tank. I don't see the need in an open system. Either way i have a fairly new one from my previous, closed, oil fueled, radiator system.

It is starting to get cold, and my pregnant wife is being very patient. I am starting to pipe the gas in tomorrow and want to get everything i need. I would appreciate any help, even if just links to better guides.

 

[johnjh2o]

I suggest you get a heating contractor to help you with the design. There are a couple of statements you made that set of some alarms. 1- it's not an open system. 2- you can't run radiant heat and baseboard heat at the same temperature. That would make it very difficult to use a tank less in place of a boiler.

 

[chukar]

A couple of other considerations, typically your runs are like 350' max, and then fed back into a header, which has to be balanced, are you planning to put the in floor on ground level or upstairs because there are considerations for the weight of the light weight concrete to sit on the pipe, or is it going to be run in the floor joists below. For the boiler you need to size it off the heat loads, pulling a model outa thin air isn't something you want to do.

Further more your starting the gas line you save have you sized it correctly, are you going to get 200,000->400,000 at the end of your run depending on your boilers needs.

I'll be honest it's best to use a proper contractor for this kind of work the prices will not be cheap, but it's not a small under taking.

 

[whizeazz]

I know it's always in everyone's best interest to hire someone to do the installation. Unfortunately it's not always in the budget. I will look into it to see about having someone at least lay it out. I was under the impression that this is an open system because i plan to run my domestic hot water off the same system. Maybe i wasn't clear in my explanation.

 

[whizeazz]

chukar: the reason for the different types of heat is because everything is finished. I am running the radiant on the main level through the joists and wanted to do baseboard on the 2nd floor and basement because of lack of access. I was not aware of the different temperatures of the two systems. seeing as I am starting with a clean slate, my first option was to do forced hot air, but i thought the radiant would be less destructive. I guess i'll have to have someone come in and go over my options. As far as the gas goes, I will be fine. I am running 1" pipe into the house. The pressure from the street was supposed to accommodate a lot more than it will be.