iDRY Vacuum Kilns

Sponsors:

Accumulator tanks

Started by farlet, March 29, 2015, 04:08:42 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Holmes

The other option is to collect heat from the day time burn , store that heat in the tanks . That energy will be released thru the night extending by a few hours the cooling off of the house. If he can figure out how to make the storage tanks work  in a gravity feed system.
  What is the size of the heating main? 3 to 4 inch?  Do you have a side arm tank less heater?    Any handy usefull tapping on the boiler to connect to or on the main?
Think like a farmer.

John Mc

Quote from: Gary_C on March 29, 2015, 09:24:39 PM
John, as I understand the system, his firing rate in the stove is limited by boiling in the hot water system. Unless he can change the ratio of the heat going into the two systems, he is stuck with the same firing rate. So the only way to get more heat in the house is to fill the stove more hours in the day.

I thought he had more capacity during the day. From reply #12:

Quote from: farlet on March 29, 2015, 04:30:39 PM
I am pretty sure that during the day, there is spare capacity in the system as the house gets pretty hot. Actually, this is one of the downsides of the gravity setup in that it isnt very controllable, and you can get to where you have to open the windows in the middle of winter.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

John Mc

I wonder if there is a way to use pumps on the loop for the storage tanks, while still keeping your existing system mostly as it is, allowing for gravity/thermosiphon operation?

This would mean in a power outage, you are no worse off than you are now, but when the power is on, you could use your storage system. You could have electronic controls which put heat into storage when there was excess capacity, and drew it back out when the house or boiler started to go cold.
If the only tool you have is a hammer, you tend to see every problem as a nail.   - Abraham Maslow

Gary_C

Quote from: John Mc on March 29, 2015, 10:33:13 PM

I thought he had more capacity during the day. From reply #12:

Quote from: farlet on March 29, 2015, 04:30:39 PM
I am pretty sure that during the day, there is spare capacity in the system as the house gets pretty hot. Actually, this is one of the downsides of the gravity setup in that it isnt very controllable, and you can get to where you have to open the windows in the middle of winter.

He backed away from that claim in reply #15:

Quote from: farlet on March 29, 2015, 04:49:57 PM
I dont mean that we open the windows every day, its just now and then when you let the furnace burn too hot. What I meant was that once you have done this, it takes a long while for it to come back down to a sensible temp hence the open windows

Perhaps those too hot days were when the hot water system boiled?

It appears the bottom line is until you uncouple those two water systems, you cannot put more wood in the fire without extending the hours per day you run the system. The first law of thermodynamics (conservation of energy) tells us that you can't get more heat without adding more wood.
Never take life seriously. Nobody gets out alive anyway.

Holmes

John Mc I think that pump idea is a good one if he can't get the heat from the storage tanks by gravity. Placing a circulator in the wrong location could drive all the heat into the house very quickly.  I do understand how difficult this heating system is to control {perpetual manual dampering}, trying to get as much heating without boiling, not get to much heat in the mild days and control creosote.
One other item could be to give the house more thermal mass.  Can you radiant heat a concrete floor?
Think like a farmer.

farlet

Good morning from Sweden. Very interesting, and it has made me think some more.

The hot water for the taps consists of 100 litres in the furnace, so separate tank, and a mixer valve which limits the temp out of the tap to 60 degrees C. This is what limits our temp on the radiators because the 100 litres will boil if you go over 60 on the tap water circuit. What if I added more capacity to the tap water circuit. It would be very easy to add another 150 litre tank to this system upstairs and this would gravity circulate and take some of the heat away from the tap water part of the furnace.

This would mean that in the coldest parts of winter, we could burn hotter before going to bed and get the radiator circuit up to 70 or even 80. This I am sure would have a big effect through the night.

What do you think ?

Someone was asking about the triple glazing. Before the triple glazing, we had old fashioned double glazing. In Sweden they are called cassette windows, they are two single glazed windows sandwiched together. Whilst they work OK and are draft free, the triple glazed windows are totally amazing. We have friends in the village with modern double glazing and when it goes below -40 C, theirs have ice inside on the bottom corners. At the same time, our triple glazed were warm to the touch inside.

farlet

Sorry, its early here and I typed a few errors on that last post.

Meant to say that there is no seperate tank for the tap water just the 100 litres in the furnace, and that the 100 litres will boil if the radiator circuit goes over 60.

beenthere

farlet
You can edit your post (click on "modify") and make it correct the way you wish it to read. Saves others trying to sort out the correction needed. No need to add another post. Have a good day.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

farlet

Been thinking about this all day, and the more I think about it, I can see it being a great solution. We have another problem with the current system which is in the summer. The furnace is our only source of hot water, so we have to light it each day in the evening which is a pain. I have wanted to have a solar water heater for a long time and it is perfect here in the summer as we have 24 hour sun for nearly 3 months.

I have done a very rough schematic of the hot water circuit for the hot taps, 3 scenarios, 1st is as we are now, then two options for a new setup. I can buy a hot water tank for upstairs which has either 1 or 2 coils in it. 1 will obviously be for the solar heater as this will be a standalone setup, but which would be better for the furnace, option 1 or option 2 ? I can see option 1 being more effective at taking away the heat from the 100 litres in the furnace which is what we want in the cold winter so that we can burn hotter.

What are peoples thoughts on this ? Hopefully the picture works !

Thanks

 

Gary_C

Gravity fed systems are more art plus trial and error than anything else. Just from looking at your options, I cannot see how the water will circulate without a pump.

How is your cold water fed to your house? Is it thru a pump or gravity feed system? How much pressure?

I have an outdoor boiler and what they call a sidearm heater on my hot tap water tank. But the hot boiler water is fed thru a circulator pump on the outdoor boiler. From what I know of solar panels they require a circulator pump also. So I believe you are at the limits of what you can do to improve your gravity system without adding some pumps.
Never take life seriously. Nobody gets out alive anyway.

farlet

We have a well with a pump for the water. It is at about 25psi in the system. When the power goes off, then we dont have any water, but the radiator system works just fine.

In option 1 or 2, I thought that if I have big pipes between the furnace and the tank/Coils in tank, then it should circulate by gravity, is this not right ? The tank will be about 3 metres higher than the top of the furnace

From what I have read online, you can have a thermosiphon solar system which works on gravity if there is a good height between your collector and tank.


Holmes

  I like option 2. With that you are not using/ drinking your boiler water.  You can pressurize your boiler and increase the boiler water temperature.
Think like a farmer.

Holmes

   They may make a non electric bulb controlled zone valve . You could install it in the feed line with the bulb/ sensor in the control well This would give you some control over the hot water so you could run the boiler hotter.
Think like a farmer.

stratton

Hilltop, what kind of boiler do you have????.. The reason i ask is i have a d.s. aqua gem 3200.. it came with a sampson valve.Super simple design!!!!


Hilltop366

Tarm, it was made in 1978. It was unused until 2000 when I bought it.

Holmes

I put in quite a few Tarm boilers back in the 80, s.  A good product.
Think like a farmer.

mapleveneer

In regards to the posted image of the domestic hot water setup above, i don't think option 1 or 2 will work as shown or if they do work it will move only very minimal heat.  They are both shown as having supply and return connections made to the top of the 100 litre tank.  This means that they will both be at the same temperature.  The hotter water is in the top of the tank and the cooler in the bottom.  A thermal syphon requires a temperature gradient to work.  The hot water is trying to rise through both pipes at the same time, so no circulation.  Check your existing connections on the gravity hot water heating system.  Does the supply connect to the top of the boiler and the return connect to the bottom?  I suspect so as this is how you get the gradient in that system.  My house had gravity hot air for 72 years so i know how to control the house temp by opening doors and windows also!

Circulator pumps draw very little current, typically 75-180 watts.  Equivalent to incandescent lights.  If your concern is loss of power to your circulator, buy a little DC to AC inverter.  Plug it into your car's power outlet and run an extension cord to your pump.  No need for big generators or even to maintain an extra battery.

I still think you are going to have a difficult time achieving a thermal syphon with storage tanks simply plumbed into your existing piping.  A few posts up someone mentions putting the tanks adjacent to your system and using a pump to circulate through them.  This suggestion might be worthy of further consideration.  You could manually control that pump to draw heat out of your system when it is too hot and to add heat to your system for those cool mornings.  And you can leave your existing system basically untouched so that it will continue to operate as it currently does.  You want to be careful that you don't shoot yourself in the foot by making a change that reduces or stops circulation.  The end result there would be little or no heat probably when you want it the most!

Thank You Sponsors!