Munchkin Help

JDemme

Hi,

Do I really need primary/secondary piping with a Munchkin wall hung 80? I will be using the Vision 1 controls.

My goal is to have near constant circulation and want to minimize pumping cost.

There will be three 3/4" baseboard zones. One is for garage and will be used very little. The house is an open floorplan so the downstairs zone will run almost all the time and the upstairs runs only in the coldest weather.

Most of the pictures of installations on the HT website do not look like they are piped primary secondary.

Input from experienced Munchkin installers would be helpful.

Thanks!

Alan(CaliforniaRadiant)Forbes

Primary/Secondary (1°/2°)

piping is essential for the proper operation of your Munchkin boiler. Follow the diagrams in the Vision I booklet and you will save yourself a lot of grief.

"Near constant circulation" to me means that you may only have one zone calling for heat; if you don't have 1°/2° piping, your Munchkin will complain; it will rumble and eventually cause damage to the heat exchanger. It likes good flow through the boiler to pick up all the heat and carry it out and 1°/2° piping accomplishes that.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

JDemme

Thanks for the quick response.

I would like to have both "main" zones circulate constantly, but I am not sure how good comfort control could be accomplished.

With my existing boiler I have two thermostats and downstairs runs almost all the time and upstairs hardly ever cycles. Open floor plan and open doors upstairs.

How can I do constant circulation and not cook the upstairs?

Steve_35

You can get by w/o primary secondary if you use a pressure actuated bypass valve. This is shown in the Munchkin installation. You don't mention if you're going to use an indirect fired water heater.

If you are using and indirect WH you need to have a pump(s) capable of delivering the required flow against the developed head which will NOT be insignificant. This is one of the biggest reasons to go primary/secondary. If you don't and you don't use a PABV the water is going to be smoking through the space heating zones. Way too fast.

I think you need first to decide what you REALLY want out of this system and to prioritize the importance of installation cost, operational cost and comfort. Once you do that it becomes much easier to design the system to accomplish your goals.

JDemme

Thanks Pitman9.

I will be using two SS30-LB since they will fit in crawlspace. They will be piped parallel. Pressure drop is 6' at 8 gpm. I have a call into HTP for pressure drop at 4 gpm. I calculate 1.5' at 4 gpm but I am not sure if my formula is correct.

My main goals are in this order. 1. My wife's comfort, 2. Efficiency, 3. Reasonable cost. I do not mind paying extra even if not cost effective. I am an energy efficiency consultant/inspector for New Jersey Clean Energy Program. We work with Solar Electric systems and ultra high efficiency projects. Now you see why I have to over analyze everything. Been contracting to the state for too long!

Thanks for your help!

Chuckles_3

P/S piping is simpler than the alternatives. It is true that there is one extra pump, but not necessarily a higher operating cost, because each pump only has to do its own loop. With regular piping you would need bigger pumps for all three zones, to force water through the boiler, and still the zones will affect each other giving unpredictable flow rates. Plus the Munchkin needs a steady 8gpm through it at all times.

Get 3-speed pumps such as the Grundfos 15-58 (almost the same price as a 1-speed pump) and run each zone pump as slow as possible. (The boiler loop pump MUST be on speed 2.)

Rely_2

nice web site

by the way you guys have a nice web site njcleanenergy.com

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

chuck shaw

Why

are you asking such a dumb **** question? Just follow the book they give you. Do realize how much they pay for engineeing. How much education they have. Why are you trying to re work it. It has already been done for you.

Read the instructions!!! Why is that so hard???

Rebel

Wayco Wayne_2

One way

to get constant circ on 2 zones is to go to motorized mixing valves (3 ways). The Vision 2 controls set up from HTP will let you do this and give you the choice of a separate outdoor reset on each zone. Also it will change the boiler set point for each zone if it is different so if the higher temp zones arent calling you will run at the lower more efficient temps. Pretty neat stuff. WW

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Ted_9

Rebel, he wants to save $2 dollars.

Rebel, I dont agree with your approach, but you make a very good point. I fact, most of the diagrams in the installation manual are P/S piping. Let me go into more detail. In the regular Munchkin manual, the 1st 2 diagrams are not P/S. The rest are. I the Vision one book, all of the diagrams show P/S piping.

JCD, its not much more to do it the right way.

PATRIOT HEATING & COOLING, INC.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

JDemme

Thanks Rebel for your RUDE answer to a simple question. You don't need to respond if you have no sensible input. As an energy consultant I earn a fantastic amount of dollars annually. I never realized that the American dream was attainable by an average non-college educated guy. I earn substantially more than my lawyer, typically by not following the directions. Anyone can follow the directions.

My hero's, Wilbur and Orville, did not follow the directions. Parasitic pumping costs can be a substantial portion of the heating energy load in a well insulated home. I deal with micro-load homes where a couple 007s on constant circulation can be more than 10% of the electricity consumed by the home.

My goal here is energy efficiency. If it costs triple to install but saves some energy, then it is a success. This is an experimental system.

JDemme

Thanks Wayco. I will check into this!

jerry scharf_2

This information would have been helpful in the first post

JCD,

When people post here, 99% of the time it is for residential or commercial installs rather than experimental systems. If you don't tell people this is an experiment, people have to assume that it's for a customer who knows little about the operation of their heating system. In that case, rebel may have been tactless, but not so far off the mark.

The question is if you use a larger pump to overcome the head loss in both the boiler and the system loop, would that use more or less electricity than two smaller pumps each carrying the specific load and volume required. I've had the same question and decided not to tackle it on this round of plumbing.

When I thought about the experiment, here's what I came up with plumbing wise. On the closely spaced tees attaching the boiler to the system loop, put a full flow ball valve like you would for power purging. Then use add a bypass loop with a full port ball valve around the boiler pump, and make sure there are isolation valves on the boiler pump. This allows you with just the swing of a few valves to change the piping from P/S to single loop. I would also want to make sure I had something that allowed me to change the type of pump I'm using to run the primary loop (they can vary in flange to flange distance.) I will probably do the boiler pump bypass part, but not the setup to take different pumps in the system loop.

I think you understand what the deal is with the flow switch in the munchkin, so the rest is really up to you.

I wouldn't do any of this in a system where wasn't someone who was quite experienced with boiler systems was around to babysit things.

jerry