Help a newb with diy design

tbrooks

Well, I'm doing as much planning and reading as I can in my spare time, but your inputs could help speed me along. This was originally a 28x32 duplex, that I have gutted. I just finished the foundation for a 16x28 addition, hoping to have it dried in before the new year. The garage will hopefully be built next fall. I did a design myself about 6 months ago, but alot has changed since then. I am planning a mod con boiler with outdoor reset, hopefully an htp, but not exactly sure yet. Wood framed floor with crawlspace on everything except garage, doing diy plywood strips above floor, with stamped aluminum plates, 1/2 pex, for my emmiters. I have a non-existent budget, and it will probably take me a few years to actually get all my components. I'm trying to keep everything as cheap as possible, but I don't want to sacrifice quality, or create an inefficient system.

I just finished all of my room by room calculations, and this is my crude zoning plan. Btw all btu/hr/ft calculations are based on unblocked floor.

I know its alot of zones, but there is reason for that.

-Zones 1&2 are my older kids' rooms, and they are only with me for half of the winter, so I would like to be able to throttle those down when they are gone.

-The btu requirements for zone zones 1 and 3 are so much higher, that I don't think its wise to combine them with 2 and 4 (respectively).

-I don't have any pipe planned for the hallway, I don't think its necessary, thoughts?

-zone 7 is the garage, and will be where my system is housed (blue box)

On my previous plan zone 6 will have 4 circuits. Zone 7 is new (from previous plan), and will be in slab, I still have some figuring to do there. All the other zones will simply be one circuit. I am thinking one manifold in the garage for zones 6 & 7, and one manifold centrally located, underfloor, for the rest of the zones.

I have alot more things to work out, but this is where I am at, at the moment, just wanted some input on zoning, distribution, etc. Thanks

Ironman

Mod/con's are low mass. Unless a buffer tank is used, it's gonna short cycle with all that zoning.

tbrooks

Thanks for the response. Nothing is set in stone here, as it will be awhile before my system goes in. Thats why I'm here, so you guys can show me a better way I was planning a mod con for efficiency, @Rich was pointing me in the direction of htp when I was trying to do my design this spring. They seem to have some really nice products, although you do have to pay for them lol. Would be nice to have thats for sure. Either way, whatever I have to get, I have to get.

I wish there was a better way to do the zoning, but I can't see it. I forgot to add I do want dhw through the system, somehow, either combi or heat exchanger, but it will be a closed system. Also hoping that I can get away with one variable speed delta-p pump, but not sure that I can.

j a_2

tbrooks said:

Thanks for the response. Nothing is set in stone here, as it will be awhile before my system goes in. Thats why I'm here, so you guys can show me a better way I was planning a mod con for efficiency, @Rich was pointing me in the direction of htp when I was trying to do my design this spring. They seem to have some really nice products, although you do have to pay for them lol. Would be nice to have thats for sure. Either way, whatever I have to get, I have to get.

I wish there was a better way to do the zoning, but I can't see it. I forgot to add I do want dhw through the system, somehow, either combi or heat exchanger, but it will be a closed system. Also hoping that I can get away with one variable speed delta-p pump, but not sure that I can.

Honestly go with what @RIch said...HTP is the true way to go....Select the product that fits your demands,the pioneer is awesome..no primary secondary required and it has a built in mass as a buffer

Gordy

Still,gotta keep zones to 8k with the UFT. Yes the pioneer. Low end 35k, but with mass make the 35k when you need to at your leisure.

tbrooks

Thanks guys. I've been thinking about my zoning all day. I'm thinking, its only 3.5 years until my oldest daughter graduates, then my youngest will get her room (zone 2). So long term, it maybe be wise, and better for my system to go ahead and combine 1 and 3, and also 2 and 4. And could I possibly combine 5 with 2 and 4 by decreasing pipe spacing?

I'm trying to learn with siggy's book, but there is just so much info in there. I'm on my second pass of reading it, but I just have so much going on right now, its really not sticking with me well.

Gordy

Tight tube spacing is your friend. It helps lower awt of the system. Emitter saturation is key.

tbrooks

Would this help the system function better? It will cost me a little extra on the bill for the first 4 years


If it helps efficiency/design than I think I should do it.

tbrooks

After looking back through my old post rich said in summary, t-stats are cheap and comfort is priceless.

That is a good point, maybe I will keep my 7 zones. I don't want a cold room, because the heat output/loss doesn't work exactly as planned

Ironman

Comfort is not an issue in a properly designed system and it doesn't require all that zoning to achieve it - especially in a house that size.

But all that zoning will result in lower efficiency and a very early death for mod/con boiler, unless a buffer tank is used. And it's really not gonna give you any benefit, though you may be perceiving it to.

Gordy

I'm not a zone fanatic in smaller homes. Maybe bedrooms.

SWEI

We zone principally for two reasons:

1. Solar or other external heat gains (woodstove, big kitchen, etc.)
   
2. Intermittent occupancy
   

Most anything else is better handled by proper sizing of emitters and piping IMO.

Gordy

@ tbrooks if you take the cost of zoning with pumps or valves, and thermostats, or trvs times 3,5 or 7. Think of how much closer you would be to a step up from "cheapest" floor radiant.

Your only talking about less than 1600 SF. Also deep setback in a room will create a heat loss to adjacent rooms.

Gordy

Also,the main bath looks a little shy on emitter area for floor only. Don't forget the walls, and ceiling for some extra radiant output.

tbrooks

Thanks guys. @Gordy the bath calculations were figured by using the unblocked floor, so emitter size is already considered. That includes no pipe under the tub, cabinets, and leaving room around the toilet.

I haven't really considered solar heat gain in my design. Mainly because I will only have 1- 9sqft window per room. However, the bottom of my drawing will be the south facing wall. I plan to eventually have a large covered porch most, if not all of the distance. Until then, it will be exposed. I guess that heat gain may play a factor here although it maybe insignificant.

Something else that you guys, and I must also take into consideration as well is that I have 3 daughters and a wife. A few degrees difference in temp between rooms could be a big headache for me lol.

Also, I didn't mention it before, but I have also considered using a wood boiler. Originally, before I had even planned to do radiant, this was an option in my head for my future home. I am thinking that it would have more mass and help with short cycling. I like being less dependent on the utilities. I had a wood fireplace insert for many years, and I didn't mind the extra work, my wood shed was usually full by june at the latest. The only part I didn't like was the horrible heat distribution, which wouldn't be an issue with hydronic. I also am partial to the thought that it may be possible to run a steam engine from a wood boiler, and use that to spin a generator to power, at minimum the hydronic system, incase of power outages or zombie apocalypse lol. I didn't think of it much before on this because of prices I had seen years ago, but now I have a better idea of actual needs and maybe able to get a cheaper one.

Anyway, off to town. I get the day off because the jet pump for my well went out last night. Its an old monkey wards. I'm gonna go ahead and redo most of the old plumbing mess, new foot valve, etc so its going to be a fun day!

Gordy

I have daughters,and a wife.

Rich_49

If people like to have the option to zone to deal with differing conditions due to use , solar gain , wind direction they should be able to .
We as professionals must take that into account and adjust what we use and how we use it . At the end of the day what the customer wants will drive what we design . Not to say that some folks cannot be reasoned with and want to do stupid things . These are the customers whom I tell , " I am not your guy , Good luck ".
Tony's desire to zone because the loads from South to North and East to West will always vary based on unknown things like wind and sun is not one of those things . Varying tube spacing , and the many other strategies cannot ever account for these things . We can perform these things based on historical data and local knowledge but in the outside world of nature we never know exactly where , when and how things that affect our loads will happen . Zoning allows us to have properly sized emitters , total comfort , controlability , efficiency system wide and a happy homeowner . Who are we to determine what your comfort level should be and / or what you should tolerate . Comfort should be easily controlled by the users of the ares being heated . Many times this can only be done by zoning .

No reason with the present choices we have for boilers and mass storage devices or a combination of both that Tony cannot do this with more zones and not be in jeopardy of short cycling or efficiency hits at the equipment location . Think high mass combi Guys .

If you're hooked on a specific brand , strategy or something other I guess this can be difficult to grasp . The zoning argument is not really a valid one anymore in my opinion .

I know you guys know this to be so . Hey , we all love panel rads with TRVs . That's alot of zones and the emitter sizing is well , not that difficult as long as they are big enough , larger does not hurt either .

hot_rod

Run all the loops to a manifold. Select a manifold that allows you to add actuators should you decide to break up some zones later on, or combine zones. Wireless t-stats allow you to add additional zoning after the fact.

TRVs are excellent for zoning panel or standard CI rads and can run from manifolds, just leave the actuator off any loops you plan on TRVing. I'm not a huge fan of TRVs on fin tube baseboard, awkward location prone to damage.

The Oventrop Uni-Box is nice for TRV zoning of radiant if you can work within it limitations for cap tube length.

Tight tube spacing, for lowest supply temperature leverage. I'd suggest 6-9" spacing. Tube is cheap, and it is one area that cannot easily be upgraded. 1/2 pex 250- 275 max length to keep pumping head to a minimum and lessen temperature drop across the loop.

Some of my thoughts.

Gordy

I agree with both of you. Zoning can easily be done later if planned for. In the end my goal to the op is a better emitter surface now. Save the money for zoning later. One chance for a nice output floor. Yes tube is cheap. Easy to add zone valves to manifolds later,

Ironman

I have six daughters, a son, one wife and four grandchildren. Most of the girls are cold natured, but the wife is at the hot flash stage of life and wants to sleep with a window opened - no matter how cold outside.

Gordy

Hey at least it's consistent. My wife one time to hot, next time cold.. Hard to keep up with that.