Heating Help

No mesh

@ May 26, 2012 9:35 AM in concrete overpour over wood floor - reinforcing

Mesh in concrete only works if it is imbedded. Laying it on the subfloor will do nothing. if you could center it in the slab it would help, but you can't, it is to wavy. If you are concerned with cracking, fibermesh would help. Also do not use "lightweight" concrete as it will resist the heat transfer. The product you want should weigh about 105# per cubic foot. I would consult the batching plant to be sure you are getting the correct mix for your application.

BTU calc

@ May 25, 2012 10:42 PM in What's best: Replace Radiator with Heat pump/HVAC or...

Here is the like to that spreadsheet http://www.eia.gov/neic/experts/heatcalc.xls
You may get a better handle on pricing by contacting someone in the "find a contractor" section. It sounds like Ironman is nearby. You can send a contact request to any user by clicking their name.

This will work

@ May 24, 2012 11:53 PM in DPDT Aquastat

The 003 has 8 terminals. 2 energize the coil. The others are, 3 for one contactor and 3 for another. The contactor is common, NO, NC. If the aquastat (powered by any transformer with extra capacity) closes, it will energize the coil. When this happens you can close one set of contacts and simultaneously open another( one boiler is wired c and nc the other c and no).This will turn off one boiler and on the other.
2 separate poles that can throw both ways
Voila
I have used this on wood boilers with gas backup, it works great.

http://tekmarcontrols.com/accessories/003.html

Questions

@ May 24, 2012 11:34 PM in replace undersized radiant demand with boiler

Is the existing demand heater also doing domestic hot water (open system). If not how are you heating the DHW? A modcon boiler is best for in slab radiant. I would use low temp radiators upstairs when the time comes. I would not be to concerned about being oversized prior to expanding. Modcons can turn down to 20% and are most efficient under light loads. Don't do a conventional boiler with radiant, you end up heating water just to mix it down. you will see 20-30% better efficiency with condensing.

That's it

@ May 24, 2012 10:56 PM in What's best: Replace Radiator with Heat pump/HVAC or...

Ironman's post is right on. Everyone has there favorite boiler. I prefer firetube hx types like the dunkirk and triangle tube. If you have the cost of your fuel options it can be pretty easily compared. Generally, it goes nat gas, propane, heating oil, electric (that's low to high) It can vary by region.

Potasium Cyanide?

@ May 24, 2012 9:45 AM in Choosing an Indirect Hot Water Heater

If you are filling your boiler with toxins you have larger problems. Bacteria will not live in a non-o2 environment. In all likelihood the failure will happen on the outside of the tank causing flooding.
Did I miss some irony or are you really worried about nonexistent toxins going from low pressure to high?

Sounds good

@ May 23, 2012 11:13 PM in What's best: Replace Radiator with Heat pump/HVAC or...

I think your approach is solid. Some smaller A/C units upstairs and restore the radiators to their former glory.
What are your fuel choices? You mentioned oil and electricity. How about propane or natural gas? What is the local cost of the fuels you are considering?
How are you heating your domestic water? Should this be part of the solution.
Post some pics of that beautiful old boiler!

Thanks Bob

@ May 23, 2012 10:54 PM in Electrical question

Bob,
Thanks for the explanation. I knew the how but not the why.
Multi branch will soon be a thing of the past since it is incompatible with arc fault breakers which are required on most circuits.
Carl

Cube relay

@ May 23, 2012 10:31 PM in DPDT Aquastat

Why not use a regular aquastat and a cube relay. Tekmar 003 is one but everyone makes one. You have 2 separate dry contacts with NO/NC. Truly DPDT

Recovery Rates

@ May 23, 2012 12:15 PM in Glass Lined versus Stainless Steel - Indirect HW Heater

Pickypro,
Thanks for the info on chlorides. It makes for good "brain food". I think we need more GC's with your interest in the details.
Have you looked at heatflo stainless indirects?
I think State makes a lined model with a non stainless coil.

As for the recovery rate subject. Most of the indirects that are coming out today have a bigger exchanger than the boiler powering them. If you take the input BTU rating of the boiler and derate it for efficiency you will get your output BTU's. If you divide that number by 500 and then divide that by your delta t you will get the max gpm the boiler can produce. 
For example, A 100,000 btu 80% efficient boiler  (at sea level) heating water from 60 degrees to 120 degrees would look like this 100,000x80%=80,000  80,000/500= 160    160/60=2.6 GPM

2.6 GPM is the max this boiler can produce no matter what exchanger you hook it to. One problem that arises when using an oversized indirect is that if the boiler is not piped correctly it can drag the boiler temps down and cause condensation. This great for condensing boiler and horrible for non condensing.

Beyond that the only variable is how much water does the indirect store.

Tekmar

@ May 22, 2012 8:41 AM in Need help converting from oversized CI Rad to CI baseboards

I like what icesailor is saying. We have done this using a tekmar to control the boiler and the mixer. The boiler will fire to the temp of the highest temp load.When only the old system is calling the boiler will fire at the low temp and the mixer will be wide open

Trial and error

@ May 21, 2012 11:59 PM in Need help converting from oversized CI Rad to CI baseboards

If you had a home that was easy to do an accurate heat on and you had the calc tables for your radiators output at different water temps this would be a pretty simple thing to do. I am guessing you do not.
I would try a reset curve that supplies 150 degree water on the coldest day and 110 degrees on the warmest. If the t-stats are not being satisfied, I would raise the temp. Lower temps may also work.
Some would see this as guessing. I see it as a SWAG based on experience.It is not as if you are installing a system based on a guess. You will just be "tweaking" your curve based on real world conditions.

Tap it

@ May 20, 2012 11:15 PM in Cold showers?

If you tap the side of the tank with a screwdriver it should make a hollow ping for air and a dull thud for water.
Post a pic of the tank and the valve, if the tank has an isolation valve it should be an easy swap.

Cross Connect

@ May 20, 2012 10:39 PM in Cold showers?

It is certainly possible you have a malfunctioning mixing valve. Mixing valves are not all that common in homes and would not normally be concealed. I suspect you have a cross connect between the hot and cold somewhere in the house. I would look around for odd plumbing connections under sinks ect. A common one is hot and cold hose connectors with "Y"  hoses on them. I would start turning off the valves in suspect areas and try to eliminate the problem.
Expansion tanks would normally be around half full of water. You should be able to tap on the side and tell if they are bad. You can use a bike pump on the bottom and attempt to re pressurize. If the bladder is blown you will have to replace it.
You are certain the tank is heating to 120 right?

You have a Mod/Con

@ May 18, 2012 8:54 AM in Need help converting from oversized CI Rad to CI baseboards

You have a mod/con boiler that is capable of outdoor reset. If it is not already that feature should be functioning.

With a mod/con, oversized rads is a great advantage. You can run low temp and get great efficiency.

I would do an accurate heat calc, the rough ones you are doing sound high. With this calc size you new radiators for low water temps. Maybe 140 on the coldest day.

The main difference between the CI products and the flat panels is mass. The flat panels will react more quickly and are well suited for spaces with solar gain. I would use care not to mix and match within a zone , but would not worry about having a CI zone and a low mass zone. You may also want to consider TRVs.

Your near boiler piping is not primary secondary. This has likely been working fine because your old gravity piping is huge. If you begin to add smaller piping and zones, this will need to be addressed.
 

Are you?

@ May 18, 2012 12:14 AM in replacing heating distribution pipes with pex

Are you looking for a boiler bipass to prevent condensation, or a diff pressure bipass on the manifolds?
How is it piped now?
Due you know the minimum flow for your boiler?

TRV

@ May 16, 2012 11:00 PM in replacing heating distribution pipes with pex

I really like the system Slimpickins described in his first post.

 If you can I would certainly home run the rads.

If TRVs and outdoor reset are not in the budget today, You can manifold several rads together and have the floor by floor zoning you describe. You will have done the infrastructure needed for the perfect system down the road.Eventually a modcon boiler.

If your contractor was seriously planning 1/2" in series, I am not sure I would let him back in the house.

I like

@ May 16, 2012 10:31 PM in Heating n00bie

You can find all you need in the store here at heating help.
I have most of Dan Holohan's books and enjoy them. He has a very practical and easy to understand approach.
Modern hydronic heating by John Seigenthaler is a great one. It is written more like a college textbook. If you are intimidated by long mathematical equations, it might not be a good place to start.
Carol Fey is tops on the control side of things.
If you like webinars, take a look at taco's flow pro university. John Barba is a great teacher.

Best of luck,
Carl

Heat Loss Calc

@ May 15, 2012 10:14 PM in Hot water baseboard heat

You have to do a heat loss calculation. Once you have that you need to look up the output of the baseboards you intend to install at the water temp you intend to use.

Taco has free heat loss software on their website. The "Flow Pro University" section will even show you how to use it.

Demand heater

@ May 15, 2012 9:00 AM in how to lower water temp

I just noticed that you no longer heat with this unit (intentionally). A instantaneous heater might be a better call.

There is

@ May 15, 2012 8:57 AM in how to lower water temp

There is a high limit (don't touch) and an operating stat inside the gray box. If you decide to lower the temp you need to observe the boiler return temps under full load to be sure you are not condensing the boiler. Your returns should not be below 140. You may be able to go as low as 150 on the operating stat. If you are all uncomfortable with electricity or the operation of the stat, call a professional.
If I were you, I would start making plans for a new unit. Your setup is a very inefficient way to make heat and hot water. With little insulation and no flue damper so you are heating the room and the outdoors as well as the water.A new condensing boiler would save 30-50 percent easily.

2 pipe?

@ May 13, 2012 10:33 PM in basement hot water loop

I assume you have a 2 pipe system? Water in a typical 2 pipe closed system is unaffected by gravity. The additional piping will add some head loss to your system. Is this a separate zone or are you extending an existing?