Advice on tweaking my new system.

[tmudd]

Hello everyone. Glad to be a part of such a great site. I almost feel guilty for having gleaned so much useful information and not having anything to contribute. I have been watching from the sidelines for 1 1/2 yrs. Slowly making an outside shed for the 150,000 rated Omega gassifier, bringing in insulated 1 1/4" thermo into the house, running a primary secondary set up similar to Hot Rod Bob's recommended approach. So far completed is the following.... Outside boiler loop into house ( 1 1/4" thermo ) with it's own Grundfoss 3 speed circulator meeting inside primary loop( 1 1/4" copper )with a Grundfoss 1558 three speed circulator,r feeding 1st zone of ssecondary loop for heat exchanger in ductwork.(1" copper with a 15-58 grundfoss3 speed circulator. The 2nd. zone fed with a (1" copper main run through a Caleffi manifold 6 zone manifold with a Caleffi mixing valve feeding 3- 1/2" pex floor loops run in extruded aluminum emisson plates under main level. 3rd zone not complete with a( 1 1/4" loop) to future storage 1000 gallon propane tank to be set in another building 100' away. 4th zone is a another (1" secondary loop) going to a manifold for future radiators, or baseboards Taco 6 zone controller. The system is up and running and the boiler seems tobe operating like iit should.using alot of wood. The learning curve on firing the boiler has been steep, and still needs some tweaking. The heat exchanger is on line and seems to zap the heat out of the system real fast. The boiler is set on 170 and the aquastat on the primary loop keeps the fan coil from turning on until the water is 140. Is that to low? The delta between going into the heat exchanger and coming out of the heat exchanger is about 20. Is that normal? The floor heat will not satisfy the demands of the whole house but keeps the house more comfortable. the mixing valve is delivering about 120 degree heat to the under floor but is coming back at about 70. that seems to be alot of difference-may have a faulty gauge. My question is how to regulate the valves on the return side of the manifold to produce the most heat? What pump speed produces the most heat? I gues I don't quite understand the relationship between throttling down the valves at the boiler and at each primary seconday location and what impact that will have on the system.The house is comfortable but not overly warm considering the investment I have made so far. Some things that still need to be completed are storage, insulating underfloor(none presently) and hooking up my return air ducts( presently drawing return air at the side of the air handler.) I know these things will go a long way toward improving the system. Thanks in advance for any info you guys can lend and thanks again for such a great informative site.

T-boy

 

[Hunderliggur]

First question: How is your wood? What is the moisture content? If it is not about 20% or less you will not get maximum heat. It is not unusual to get behind on the wood seasoning front. Two years for most wood AFTER it is cut, split and stacked is the norm.

Second question: What kind of radiant floors? Radiant works best at a constant room temperature. Room temp return is not unusual until you get the mass warmed up. My floors run at about a 20F delta T but I keep my house a constant temp: 70 for us old folks, the kids like 68 upstairs (who am I to complain). Floors are 3/4 bamboo over 3/4 ply-subfloor with staple up plates.

Third question: What is your computed heat load and what is your rated boiler output?

Welcome to the club.

 

[tmudd]

Hunderliggur,
Thanks for the response. I have been burning wood for primary heat just short of 35 yrs. the wood is redoak-white-oak mix split and seasoned for a 15 months.
If anything, the wood is too dry when I get to the tops of the logs that were dried out. The wood has been stored under roof for the last 6 weeks.

The on paper load of my log house is calling for 79,000 BTU. this was done off the " build it solar site" heat calc and backed up by a local HVAC contractor in my area. Both load calcs are simple plug in values for roomsize, windows, glazing, ceiling heights. insulation values,etc. The house is not the tightest, and I do have a great room with high ceilings. My radiant is snapped into heat emisson plates sold by the "Houseneeds Company."

The furnace makes claims of 150,000 BTU's. I do know it is a large firebox and will hold at least 10 good split staves. 17 cu ft to be exact. I have not totally loaded up, but the weather is mid mid 20's -30's with daytimes warming to 40 degrees. No matter what I do with the valve on the manifold, the retun temp shows no change.

 

[stee6043]

15 months will not render most types of oak "too dry". Most will tell you it's not even useable yet. Oak seasons slower than most.

Did you say your in floor loops are not yet insulated underneath? The radiant experts will tell you this is a big issue that needs to be addressed ASAP.

 

[Hunderliggur]

Your basement (I hope) must be toasty "insulating underfloor(none presently) "! The first season I ran my system as a pre-heater since I did not have the $ for the in tank heat exchanger. I kept my basement at about 80 and really helped the first floor. I found (and calculated) I was loosing a TON of heat from the uninsulated supply/return between the boiler and the storage. I have radiant barrier below my underfloor radiant and that works well for the first floor above the basement. I do not detect significant heat loss down. Long term plan is a dropped ceiling in the basement with insulated ceiling tiles. Second floor has R-11 below the radiant barrier (on top of the ceiling sheetrock). You are probably loosing too much heat to the basement from the uninsulated underfloor system. Put something (almost anything) up there and see how it changes.

I also bough an IR thermometer (auto part store, reasonable and effective) to measure the surface temp of the floor. You can also spot check areas in the basement to see where your heat is going. As you describe it, the 70F return is probably what is left over after heating the basement. I see a 20F delta on my radiant. You may also whan to step up your circulator speed if you can to move more heat through the system (if you have any to move).

 

[goosegunner]

I do know it is a large firebox and will hold at least 10 good split staves. 17 cu ft to be exact.[/quote]

10 halves to fit in a 17 cubic foot firebox are some really big pieces. Most people here use playing card size splits especially if it's not well seasoned.

gg

 

[tmudd]

hello fellow boiler mates-

i have had a breakthrough on the delta issue on the radiant problem. Evidently air was trapped in the mixing valve area. When I initially put it on line I was concerned about not getting the floor too hot. I have read somewhere that 130 is tops so as to not dry out your wood and do long term damage. I have a hardwood hickory floor over tongue and groove sub-floor and was over worried about damage, so I did not purge the system with the mixing valve all the way open to the hottest temperature. Upon franitcally trying to show a change in the deltat between supply and return , I shut off the return and throttled open the mixing valve to it's hottest setting and immediatley noticed the flow meters started working. They had not initially worked . when I put that part of the system on line. I had to mount the manifolds upside down because they come configured for pipes coming out of the floor. My floor heat comes from the ceiling of the first floor to the basement. Before installation I was worried about this, which prompted a call to the Caleffi people. The engineer wase not positive the flow meters would work in the upside down position and recommended that I loop the down and then back up to the manifold. I did not have room for this arrangement. Long strory short and do I feel stupid- there was air in the line. The delta came with in 20 degree almost within 3 minutes. I totally agree that I need to finish off ceiling reflective barrier/insulation to move heat to the first floor. The wood I forgot to add was cut from mostly standing dead trees that were terminated old age,blight,or drought, oak seems to cure in the log stage at no more than 1" per year. Split to smaller chunks where seasoning can penetrate more surface area helps.

Thanks for all the support . I wll keep you posted on my progress.


T-Boy