System control suggestions?

Grant_4

I've been reading the wall for months as I've been working on designing my new heating system. I'm doing a gut renovation on my house, replacing pretty much everything but the frame and brick. It's heat time. I'm in the Chicago area (zip 60098).



This forum/site is amazing, what an awesome group! I'm hoping you have some ideas and knowledge that you could share with me.



I've done per room heat loss calcs for my whole house and based my design on those numbers. I'm in a ranch with a walkout basement and soon-to-be-finished attic so I have three levels to heat. I'm going to be using Warmboard on the main level and panel rads in the basement. Still up in the air about the attic. My current concerns are my design temp and how to control flow/temp. A 120* temp for the main floor looks ideal based on my Warmboard design vs. heat loss. I'm hoping to just stick with one temp and make 120* work for my new rads in the basement.



Decisions I've made so far: Triangle Tube PTE-110 boiler + Indirect DHW (Smart 60), home-run each rad to a manifold using 1/2" PAP, using the same manifolds and PAP for my Warmboard upstairs.



A few questions...



1 - Can I run a fan coil @ 120* ? I want to run 2 of them in my garage... I'm having a hard time finding any info on running them at low temps. Obviously I can plan on oversizing them like I would my rads vs. 180* temps... Even the smallest I've found are too big for my small, well insulated garages. Again, it seems to me that keeping the whole system on one temp with outdoor reset from the boiler is an ideal plan.



2 - How should I deal with zoning the system and pumping it? One pump plus a zone valve per manifold? Same thing plus valve actuators on the manifolds for Warmboard and TRVs for the rads? Or... One pump per manifold plus the actuators/TRVs?



Any thoughts?



Thanks in advance!

Grant_4

Never mind on the first question

I found Modine's performance data and the specs for lower temp operation, looks like I'll be fine sizing a fan coil/unit heater for my garages @ 120*



Any thoughts on my main question?



Thanks!

Steamfitter66

A couple of thoughts

and a few questions before i can answer.

Whats your heat loss by radiation type?

Whats your DT and pressure drop for each type of radiation?

The Excellence does not put out a lot of hot water.

I'm in the Chicago area so I can base my recommendations accordingly.

Rich_49

Panel Rads

Will they have TRVs or be controlled as a zone by other means ?

  Also sounds like you will have several different zones , How many and what will the BTUs of each be ?

 Be mindful of how you zone your radiant , the following is not a rule of thumb , some will disagree I am sure .   To zone rooms together in a radiant system the following 3 conditions must be met (all three)  .   1. Rooms must have similar BTU sq/ft requirements .  2.  Use patterns should be similar.  3.  Finish floor R values must be similar .   This is particularly important if you are using wood products . , you would not want to put the end room with 3 outside walls on the same zone with a room with only 2 walls , odds are the room with only 2 walls will exceed maximum safe temperature for the wood product or the other room may never reach desired temp dependent on which room the thermostat is in .

  

   Smiths environmental has some really well designed Fan coil type emitters that either be recessed in the wall or not at floor level where they can do the most good They have lower temp stuff .

http://www.emersonswan.com/ckfinder/userfiles/files/High%20Eff%20%20Guide(1).pdf . 

Grant_4

More info

Basement = 22,445 Btu/hr (10,969 of which is garage, planning on Modine or similar, 11,476 of which are going to be serviced by panel rads). I've estimated 750' 1/2" PAP to connect them.



Main floor = 38,241 Btu/hr - this is my Warmboard floor (3000' 1/2" PAP spread across 15 loops)



Attic = 8,076 Btu/hr - this is likely going to be Warmboard, I might decide on panel rads if we love them in the basement. Future decision, I'm adding a manifold for it based on Warmboard's loop design (1400' 1/2" PAP spread across 7 loops)



I have not figured delta T or pressure drop yet... my homework for tonight.



Thanks for the reply!

Grant_4

Thanks!

Panel Rads

Will they have TRVs or be controlled as a zone by other means ?

>> I'm leaning towards TRVs... should I be considering something else? We are currently living in the basement (where are the rads are) while we renovate the upstairs. For now I think the TRVs will be great. Once we aren't using the basement as much it will be nice to leave a few of the rooms cooler... again the TRVs seem like a great idea to me.



Also sounds like you will have several different zones , How many and what will the BTUs of each be ?

>>I don't know that I'm trying to do a bunch of zoning. That's what I'm kind of trying to figure out here. We haven't lived in the upstairs of this house yet, so I don't know how we'll use it day to day. So... I was leaning towards a zone per floor and then balancing each floor with TRVs (the rads) and flow settings on the manifolds (warmboard upstairs). I figure I can always add actuators down the road if we find that we are unhappy with a single temp floor-wide and then get into a more ellaborate control system with a larger number of zones.



Be mindful of how you zone your radiant , the following is not a rule of thumb , some will disagree I am sure . To zone rooms together in a radiant system the following 3 conditions must be met (all three) . 1. Rooms must have similar BTU sq/ft requirements . 2. Use patterns should be similar. 3. Finish floor R values must be similar . This is particularly important if you are using wood products . , you would not want to put the end room with 3 outside walls on the same zone with a room with only 2 walls , odds are the room with only 2 walls will exceed maximum safe temperature for the wood product or the other room may never reach desired temp dependent on which room the thermostat is in .



>> That sounds like solid advice! If I go per-room with the TRVs in the basement, that's covered. On the warmboard floor(s)... most of the rooms are very similar in their BTU / sq/ft requirements, it's a rectangular house, all of the rooms are at the perimeter (i.e. there aren't any rooms with no outside walls). Floor-wise I'm going to lay the same teak floor throughout the whole main level, all over new Warmboard so it's identical everywhere.



That's where I struggle with how to control this system. I'm assuming that the heat patterns will be different enough from floor to floor that I should have a tstat on each one and therefore at least those three zones. But how do I regulate the water through those? A delta T-based system like Taco or delta P like an Alpha and do I just use a pump per zone or am I better off with a single pump with a zone valve per zone?



I've been doing a lot of my design based on the Modern Hyrdonics book. Per "Steam66s" advice I'll figure out my pressure loss everywhere and try to see how balanced those are... maybe that can help with a better plan.



Thanks!

Rich_49

Whose

tubing and manifolds will you be using ?  Aggressive zoning is not a bad thing , matter of fact its pretty good to do . This allows you to run a single temp to many zones even if they have a lower temp requirement , these rooms will be more responsive also .  When the finish floor surface reaches a certain temp the T stat will shut the zone and the flow down so it will not overshoot .  Uponor EP manifolds are very good , they come with flow meters on them .  Taco  Delta T pumps or ECM Bumble Bees are a real good and accurate way to insure designed for Delta T . Although others have said they won't work with ODR there is no logical explanation for this thought . Please see the following link   http://productfinder.wilo.com/en/GE/productrange/0000001b0000accb00010023/fc_range_description . No matter how much energy is being left in the panel the flow and pressure will change on a real time basis through the use of sensors adhered to the S & R devices .  Please also read the following , they make a lot of sense and eliminate some of the mystery ; http://jbblog.flopro.taco-hvac.com/ , http://jbblog.flopro.taco-hvac.com/rikki-dont-lose-that-number/ . These would be just 2 of many on lots of subjects .

hot_rod

some answers

You are on a good path with your study of Modern Hydronic Heating. Chapter 7 talks about circulator selection. If you have multiple zones with open/ close zone valves, or the proportional type TRVs then a constant differential pressure control circ is the perfect match.



Installed properly, and set to the correct mode it pretty much creates a perfectly flat pump curve, ideal for zoned systems.



These circs were developed to be used with typical TRV zoned systems common in Europe, and embraced by those looking for near perfect hydronic control. Not a new concept, the delta P circs have a long and proven track record.

PLUMMER

Love the delta T pumps

Love my bumblebee pumps, very responsive and accurate. Sensor placement on high mass can be tricky , but no big deal