Heating Help

How low can you go?

@ February 29, 2012 10:55 AM in Mod-Con with Convectors?

I know there are to many variables to be exact. What kind of numbers are you guys using for the heating curve with baseboard. I am assuming the coldest day would be 150 to 180. Are number like 100 working on the warmest?

high numbers

@ February 29, 2012 8:21 AM in radiant heat loss because of pex placement?

A do not believe the 50 degree numbers are correct. I use "radiant precision" as a reference on this kind of stuff. The 2" insulation is going to provide a good protection against downward heat loss. The lack of perimeter insulation will have some impact, less it is below the frost layer. With good downside insulation the heat is not lost, It just takes more time to get there. I would estimate a 10 degree water diff. It would take considerable brain damage to guestimate the energy savings, A SWAG would be a couple of percent of the total heating bill. I don't believe that from a cost savings point of view the tile is worth it.

Indirect

@ February 28, 2012 5:31 PM in Indirect tank proximity to boiler

Indirect is the right move. You will have abundant hot water at a cost of a least 1/2 of electric.
Make sure it is set up as priority over the heating load and piped so it will get the full output of the boiler without causing the boiler to condense.
I think I would install it next to the boiler. You would have to run 2- 1" lines 40' and have a floor drain at that location to move it across the house.
I am not a fan of the "comfort" circulator. I have one in my house and the cold water is always warm (were do you think the warm water from the hot water line goes).
If you have access, why not run an insulated 1/2" pex run and use a grundfos regular circulator with a timer and aquastat?

Turn it off

@ February 28, 2012 5:01 PM in A question about Circulators on Packaged Boilers

I do not know the reasoning behind "always on" hot water boilers and pumps. It make tank stratification impossible and tend to wear the pipes, pumps and boilers.
I recently put a tekmar 150 setpoint controller on the tank and used it to turn off the boiler which in turn controls the pump. The nice part is you can set the differential to get the optimal cycle time.

A couple of thoughts

@ February 28, 2012 12:23 PM in Lochinvar Knight boiler problems

Bob, as usual has this problem accurately evaluated.
It appears as though the service tech may be attempting to troubleshoot by just replacing all the parts. Has he been working with Lochinvar to determine the problem?
I think that is is very likely the problem is being caused by something like,poor combustion,2" intake, overpumping, oversized boiler. and the tech is convinced the controls are at fault.
How long does a typical boiler cycle last?
Does this model have a combustion test port?
Is there a hole drilled for one?

Dead Subject

@ February 17, 2012 5:23 PM in New Lochinvar Knight Installation

If "unhappy" is "unwilling" to post a picture, I think this subject is dead. Installation has a huge impact on both efficiency and longevity. If a boilers electronics are designed for a certain number of cycles, A severely short cycling boiler will greatly reduce the life of the boiler. It is impossible to blame lochinvar without more info. I am working on 4 boilers now that are 5 years old and short cycle horribly.Many control parts are malfunctioning.

Boiler Control

@ February 17, 2012 3:34 PM in Buffer Addition

I am heading out on vacation for about a week. I am assuming your mixing valve will be adjusting for outdoor reset. The target water in the tank and the water flowing to the tank from the boiler will mixed to outdoor reset. This temp will have a target and differential.

On the other side The boiler is going to be set up to run with a return no lower that 135 and a supply of say 145 to 185. Because the boiler is returning some of the water back to itself, it can have it's own temp and diff.

If I were trying to get an accurate buffer size, I would calculate the boiler+water and it's delta T and add it to the buffer tank+zone piping and it's delta T. Then I would figure the extra boiler heat not being absorbed by the heat load and go from there.

Sounds Close

@ February 17, 2012 2:29 PM in Buffer Addition

The boiler turndown is higher than I would have thought.It is hard to get it exact without all the system volumes.It sounds like 40 or 50 is appropriate. In a perfect world your boiler will fire on a fairly wide differential (145 to 185?)and your tank  will have a tighter one maybe 10 to 20 degrees and based on outdoor reset. Make sure you boiler pump stays on anytime you have a call for heat. If it is controlled by the boiler and the tekmar turns the boiler off, you won't be utilizing the mass of the boiler and its water.

Looks like

@ February 17, 2012 1:06 PM in Buffer Addition

It looks like you are using the 3 way valve with controls to prevent condensation, good. Do all your zone use about the same temp? What is the Btu requirement of your smaller zones(or give a description). What is the minimum BTU out put of your boiler. I am thinking the buffer tank may be a bit large.I would personally figure a minimum boiler cycle at about 10 minutes and design the buffer around that. 

Solar?

@ February 16, 2012 11:40 PM in Buffer Addition

What is the solar? Is the buffer tank  also your solar storage. If the boiler fires first thing in the morning it will heat your solar storage and leave you no place to store your heat.
Give some more details on the boiler panels and heat emitters.

confused

@ February 16, 2012 2:58 PM in Calculating cost of running electric motor?

So 1.73 is used to convert from line to neutral and then again in the equation?

Thank You

@ February 16, 2012 2:17 PM in Calculating cost of running electric motor?

Thanks Larry. I am just trying to calculate savings. That makes sense.

Tekmar

@ February 16, 2012 11:46 AM in Outdoor Reset

Tekmar makes great products for this application. I would put the DHW on priority then use a motorized mixing valve controlled by the tekmar for the radiant . Many manual valves can be adapted with a motor.

unhappy

@ February 16, 2012 11:42 AM in New Lochinvar Knight Installation

I think it would be helpful to know more about your installation. Could you post a picture and give a little more history? Was a combustion analysis ever done? Maintenance?Is it piped correctly? The knight uses a horizontal coil type exchanger (same as the munchkin) They can be finicky if they are not installed correctly. No manufacture of boilers warranties electronics more than a year.

Conventional boilers require less maintenance and can be installed by any creature with an opposing thumbs. Unless the are installed with a high level of skill, they generally short cycle and will never run at 80+ percent.. 70% is a fair comparison.
 

confused

@ February 16, 2012 11:23 AM in Calculating cost of running electric motor?

I am now officially confused. I understand that it is complicated figuring 3 phase motors off the name plate.
If I put an amp meter on the running motor.
Will volts x amps x square root of 3 get me there? Haven't the other factors already played out because I am measuring actual draw?

A typical light commercial circ might be 208 volts (120 x 1.73) x 10 amps = 2080 watt (2.08 kw) ?

Best of luck

@ February 15, 2012 6:14 PM in Radiant

I would put a fairly large pump on it and give it a shot. Dan Holohan has a method of reversing the pump flow direction on a timer in order to even out the system temps. It involves a motorized 4 way mixing valve. I think it is on the wall somewhere.

Good Product

@ February 15, 2012 6:08 PM in Switch Relay or control panel

These work nicely. If you are thinking of future hot water, I would get one with a priority function.

Combustion analysis?

@ February 15, 2012 5:59 PM in Buderus- Chimney Condensation problems

The GA 124 is not a mod con and should not be condensing, Is the boiler piped in a way that will prevent water less than 140 degrees from returning to the boiler? What is the operating temp set to? Is it running at that temp? Does the boiler shortcycle when it runs? How long is the average cycle?

Has a combustion analysis been done? Look for a small hole drilled in the flue.

Is it possible the boiler leaks? There could be a pinhole in the combustion chamber forcing steam into the flue. If you turn off the fill water does the system eventually lose pressure?

I would check these things in this order.

600?

@ February 15, 2012 5:43 PM in Radiant

I am assuming someone already installed this and you are just trying to make it work? If not you should do (3) 200' loops and a manifold.
To pump just 1 gpm through 600' of pex you need 24 feet of circulator head. 1.5 gallons will take 48'. With (3) 200' loops you could pump 3 gpm (1gpm per loop) and only need 8 feet of circulator head. The problem is even once you get the water through, depending on the installation (staple up, slab) there will be no heat left in the tube. This will result in noticeable hot and cold spots.
I am not sure what you mean by "you are just trying to warm the floor". By the time you get the floor noticeably warm (80 degrees or more) you are heating the house.
More details?

How hot?

@ February 14, 2012 11:16 PM in heatin guy

Iron man is absolutely correct. What temp water are you sending to the floor? What kind of outdoor temp swings do you get? Solar gain?
The outdoor reset should work well unless you big swings or solar gains.

Anyone tried this?

@ February 13, 2012 11:59 PM in Replacing baseboard radiator

Has anyone done this using diverter tees on the 3/4" line and a trv on the radiator? I think califfe has a new diverter valve that will do this.

Who's buyin!!!

@ February 13, 2012 11:25 PM in Heating Alert! - InSinkErator

HDE,
Ever wonder who pays for this great site?
Don't bite the hand.