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Joined on October 13, 2004

Last Post on August 20, 2014

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Your exactly right

@ August 20, 2014 10:04 PM in Hydronic Baseboard Altitude Derate?

Not enough to worry about at 5000'. If your paranoid raise AWT to 170, or add more base board No?


@ August 20, 2014 7:58 PM in Hydronic Baseboard Altitude Derate?

Thermal Mass

@ August 17, 2014 3:40 PM in System's Architect

The control strategy could be tricky in that getting the btus when you need them, and where you need them, and keeping them at bay when you do not. the more high mass surfaces involved the higher the level of control needed.

I see seasonal transitions as hurdles for short periods of time. Fly wheel effect depends on how aggressive these seasonal changes happen.

I'm intrigued by this project, but Im wondering about actual real life marketing potential of such a dwelling once dialed into a production aspect. The more complex the more they run away. Lots of widgets to go bad, and replace over time.

Heck Mod/Con boilers were all the craze when they hit the front. Now we have certain people at all levels wondering about ROI for such a high maintenance complex piece of equipment as compared to a CI boiler.

Will the time come when they are the Norm yes, and its only when people dont have a choice in the matter is when these energy conservation products/structures become common place in society sadly it usually happens when its to late.

Just look at the missed opportunity from the last housing bubble. If some hard line standards for conservation were in place think of the potential that could have been.

Please dont take offense to my post Rod I see good potential with your project. But there is the devils advocate in me that sees how far the sucess will go in the market place.


@ August 17, 2014 10:55 AM in System's Architect

Is the way to go like Rich stated. More responsive than concrete floors, plus radiant ceilings in cooling mode have a little more output than radiant floors. Use RFH in some select areas baths. Tight tube spacing a must.

Use of less conductive floor coverings with radiant ceilings will give a neutral effect to the bare feet.

Thermostat for other reasons

@ August 4, 2014 10:26 PM in Oversizing hot water baseboard for efficiency?

In Ice's example would be a thermostat serving as a High limit control.

My solution

@ August 4, 2014 9:49 PM in Smart solution of outdoor shower

30Gal electric tank water heater, drained for the winter. Skip the PV panels to power the WH.

Just to give you an idea

@ August 4, 2014 9:01 PM in Pool heater

My Hayward pool heater is 150000 btu. It raises the pool temp 1/2* per hour for 15000 gal pool. Which is not bad if you plan ahead, or maintain a desired temp constantly.

So ice is pretty close in his calculations.

Those figures are by the book, and dead on real world.

One biggie will they cover the pool when not in use? Evaporation is the heatloss killer in the pool world.

And yeah keep the pool water out of the boiler eh. Like Henry said titanium HX.

Good read

@ August 4, 2014 8:51 PM in flow on system?

Gravity hot water systems have very low head.

Why not use TRVs instead of zone valves? A much better option then use a delta p, or t circ ECM flavor like the bee.

Regarding TRV control

@ August 4, 2014 12:18 AM in Micro-load Dilemma: Add Storage or Nuclear Option

It would be best to use constant circulation. TRVs control space temp ODR controls boiler/ water temp. Use a ecm circulator to curve power consumption.

Tubing in sand

@ July 27, 2014 10:48 AM in Radiant Heat Matrix Other Than Concrete.

Here is something to ponder if your going to do tubing in sand.

That is movement of the tubing expanding and contracting over time working its way to the surface. So an anchoring system needs to be implemented. I would be Leary of staking into soil as the same thing could happen over time working the staking out of the ground.

Thinking this through I would favor elevated beds with the radiant to the root system. Let solar gain heat the atmosphere with in the green house.

I would insulate the tank at all sides but the top backfill with sand allowing the tank temp to radiate into the green house. It may take some trial and error as to what tank temp would allow an acceptable air temp in the green house, and to the root system tubing.

The tank would be heated solar, and what ever alternate means.

I think a vapor moisture barrier on the floor before final floor media is laid to prevent additional water from plant watering in the green house to go in the tank area is critical along with a tank coating. Unless the tank will be plastic not a bad idea.

If this idea did not work out the tank only being a foot deep could be dug down to insulate the top in the future.

If tank is not yet purchased I would opt for a rectangular plastic tank. 67 cubic feet will give you 500 gal. A tank 6x12x1 yields 72 cubic feet or 538 gal. Insulate bottom sides cover top with sand one big emitter with probably pretty low tank temp. If my idea fails dig out the 1' of sand and insulate the top.

Polymetric sand

@ July 26, 2014 4:02 PM in Radiant Heat Matrix Other Than Concrete.

Expensive but once down and wetted when dry is hard and flexible. Main use in filling cracks for laying pavers. Polymers and cement are added to the sand for adhesion, and flexibility weeds won't grow through it.

Next thought would be a flow able fill sand with cement additive different mix designs usually richer (more cement) are the difference facilitate flow.

Your talking 1 cy 4" thick of what ever media you choose. Biggest hurdle is short load charge for redi mix
Mix it's gotten brutal around here.

Your cheaper ordering the 5 1/4 cy cut off than ordering 1 cy

Another polymer modified cold patch sell it by the bag, or go to the state or county highway maint yard. I like this option


@ July 23, 2014 1:18 PM in Radiant Heat Matrix Other Than Concrete.

Underground tank temp? Typo 550*

Buried tank location? Under green house hmmm one big emitter
Or remote?
Plants grown elevated, or in the ground?

A 500 gal tank would be darn near the
Size of the green house.

6 of one 1/2 dozen of the other

@ July 21, 2014 11:22 PM in Electric Baseboard Vs Hydronic Electric Baseboards

Like Mark says a btu is a btu, and a watt is a watt. The water or oil in the baseboard spreads the heat out over a wider time frame. A little longer heating up, and a little slower cooling down because the water adds mass to the base board. Being electric I doubt either one is superior by much to the other for 4 times the cost is ROI there?

Diaphram tanks

@ July 21, 2014 10:46 PM in bladder tank total volume - who cares?

The diaphram, or bladder in the tank has to have room to flex with in the tank this is the exceptance volume. The total volume would there fore need to be larger than the exceptance volume.

There are calculations for sizing that take into account system volume, and temperature/ operating pressure. Thats why you do not see an across the board exceptance volume being 1/2 total tank volume. It all most starts that way with the small ones but as tank size requirements increase the total and exceptance volume ratio changes.

If you look at a tank style expansion tank its usually 2/3 water 1/3 aircushion, but total tank volume depends on the system volume, temperature, and pressure.

They both operate the same way except bladder types keep the air from being absorbed back into the system water


@ July 20, 2014 7:09 PM in Advice needed on heating system install

Is actually quite elegant, and others have mentioned ..........

System Air

@ July 18, 2014 6:07 PM in Constantly purging air in hydronic system

So Icesailors explanation of how pressure effects keeping air in solution is a good one. There is one other thing, and that is temperature.

The hotter the water in the system the more air comes out of solution. So upon filling a system with fresh ambient water the system is brought up to operating temperature air will come out of solution. The pressure helps keep the air entrained in small bubbles to get back to the air seperator, or auto vents as Ice explained.

So every time your adding fresh make up water to the system your adding more air to.

Expansion tank pressure

@ July 17, 2014 8:03 PM in Constantly purging air in hydronic system

Needs to be set isolated from the system. Set that pressure then bring the system pressure up to psi to match tank psi in this case 18psi

Envelope upgrades

@ July 17, 2014 6:45 PM in Complete new system on small house

I would calc a heat loss with those intended upgrades to see how much difference there is going to be in the load.

IF you are 100% sure those upgrades will take place. I would size the boiler to that heat loss. use the higher water temps until that upgrade happens then you will be poised for lower water temps after upgrading the envelope.

What im trying to say is IF the heat loss proves to allow lower water temps with out increasing radiation. Then you may not have to add more radiation the envelope upgrade will take care of that for you.

You wont know until you run the Futuristic heat loss. And only hang your hat on that IF you are sure that will happen.

efficiency and ROI

@ July 17, 2014 5:19 PM in Complete new system on small house

As far as the indirect you can make more hot water with the indirect verses conventional, and make it at the efficiency of which ever boiler you choose to use. So 80/85 I wont say 95% because a condensing boiler wont run in that range of efficiency while producing DHW.

About the boiler and ROI. We can plan our ROI with present day utility cost, and say the ROI is not there. But what you dont know is future utility costs, and if anything will steadily increase.

Your heating emitters are High temp 180 for now. You can decrease the required AWT by adding more radiation, or envelope upgrades, or both.

The trick to get high efficiency mod/con boilers to play well with high temp systems is to
get the emitter side of the system ready to recieve the mod/con. you dont need 180* but 1% of the heating season.

If this country is ever going to get green, conservative, what ever you think the path is we ALL have to get away from the frame of mind whats in it for me only.

ROI for high efficiency is not always black and white there is always some gray, and the gray is future energy costs. The question is does one want to be in a position to be ready for it, or wish they would have been.

Im sure you have lurked in some recent discussion about this choice.


@ July 16, 2014 9:23 PM in Do I need a chimney liner?


I will jump start the future wall format.
As far as Bob's post

exterior chimneys

@ July 14, 2014 9:24 PM in Do I need a chimney liner?

are the hardest to warm up, and keep warm between appliance cycles. unlike an interior built chimney. There fore flue gas condensation is twice as bad. Both still require liner.

Is the existing chimney clay tile lined? the mortar joints between the tiles may have eroded away causing condensate to run between the tiles, and the actual masonry finding its way into the interior space of the home.

Besides above

@ July 14, 2014 8:37 PM in Do I need a chimney liner?

With higher efficiency appliances exhausting into the flue the condensing flue gases are acidic, and will eat away at the mortar, and brick your chimney dieing a slow death from the inside out. This also has a lot to do with the NFPA codes.

In the old days with lower efficienciy appliances, and higher stack temps to warm the flue to prevent condensation it was not as bad.

Is this chimnet on the exterior of the home, or running up the interior of the home?
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