Just getting started. Help!

[nwomatt]

I have just built a shop 32 x 48 well insulated with 7 - 1/2" pex floor zones. It is 150' from my house. (Approx 2500sq') today I just buried the thermopex 1" line from building to building. I plan to add a piece on the side of the shop next week to house my new gasification boiler which i have yet to buy. I was planning on a new horizon bio mass combo 60 with 1000 gal storage which also I don't have. Is the 60 a good unit?? I do have a 1000 gal. Gas tank that was designed for underground. It is thick. Can this be used for storage? I hope to learn from this site and post progress for others like me to learn. Hopefully I get a few hits.

 

[nwomatt]

I forgot to mention a few details. I want to heat the house with a rad in the existing f/a system , the hot water , and possibly a floor zone in entry way which doesn't exist yet. And of course have a heated shop all winter. Our winter last year was fairly mild but is not uncommon to see temps reach -30 - -40 for a week or two stretch in the dead of it. I burn mostly ash and birch. Cut split and dried usually two seasons

 

[jebatty]

Ambitious! First things first. 1) Determine your heat loss in all buildings to be heated; 2) determine gpm flow required and delta-T for each heated space based on heat loss; 3) determine size of supply/return piping between the boiler/storage and each heated space to carry the required gpm's; 4) determine pump head in each supply/return line and heat emiiters at required gpm's; 5) determine size of circulators needed to provide required gpm's at pump head.

For your shop, full insulation under the entire floor (2" minimum) as well as perimeter insulation and vertical insulation down to the frost line around the perimeter is pretty important, and will make a big difference in heating the shop in your cold climate. My shop is the same size as yours, 14' side walls, and our winter temps approach yours as well. My boiler and 1000 gal pressurized storage is in the shop, 6 - 1/2" pex loops. I keep the floor sensor set at 61F, interior shop stays 55-64F, with 55F during really cold periods and 64F high during very mild periods. I plumbed for a unit heater to provide a heat boost when needed, but I never installed the unit heater -- don't need it.

I know nothing about your desired boiler. If your system and storage are to be pressurized, a gas tank will not work for pressurized storage.

Have fun.

 

[nwomatt]

Thanks Jim. Is there a site or somewhere I can go to help me figure out the sizing stuff. What type of a tank do you have? Are you happy with the Tarm?

 

[stee6043]

Welcome to the site! From what I have heard the Biomass is a great unit. Depending on your predicted load you may want to consider a 80Kw unit. There is no downside to having a larger boiler if you're running storage. And -30 to -40 is likely going to create an above average load depending on the house/shop setup.

I'd be willing to bet you can find 99% of all the information you need right here on Hearth. I know I did. Read on....read on.

 

[flyingcow]

Jebatty asked about insulation under your slab. Did you do that? If so how much?

 

[nwomatt]

Yes I have 2" of rid god foam under the entire slab. I have not done around the outside yet by will before I landscape

 

[nwomatt]

I am on the hunt for storage now. I'm pretty sure I can get used lp tanks but how do I clean them??

 

[VTHeatGeek]

I have about a 3000 sq ft house with a 28 x 32 attached garage that I can heat with no problems using my Biomass 60 with 500 gallons of storage. I only have 2 cast iron radiators in the garage and they are plenty to keep it warm. I used 1 1/4 Thermopex from my outside stove building to the house which can transfer about twice the BTU that 1" pipe can so I'm not sure a larger boiler will help alot except for bringing storage to temp quicker. I would definitely used 1 1/4 pipe in the boiler shed to storage to get the BTU transfer.

 

[maple1]

I am on the hunt for storage now. I'm pretty sure I can get used lp tanks but how do I clean them??

All I did was get the tank situated so there was an opening at the low point for water to run out, stick a bent pressure washer wand in an upper port, and have at it with the pressure washer. After all was said and done, I'm not even sure that was necessary - they didn't seem to be very dirty. I've got my tanks sitting horizontally not quite level, with a drain on the lower end (in/out port on higher opposite end at bottom). Thinking the dirt should collect at the lower end at the drain (which is right under the top tank in/out port) and I can just drain a bit once in a while - like a sediment drain.

EDIT: that's the inside. Outside was looking kind of ratty, so I just wire wheeled off the loose stuff & gave it a coat of rust paint with a roller.

 

[mikefrommaine]

I have the biomass 60. Been burning for a year and would buy it again. Depending on your house heat load 1" pex might be on the small side as others have said. I'm adding storage this year and plan to use 1.5" between the boiler and my tanks.

 

[goosegunner]

If the storage is in the shop instead of the house the 1" will not matter as much. You can run large pipe from boiler to storage and use the 1" for the house load from storage.

If you want storage in the house you could do that too. But it would probably be nice to have storage in shop and house. You could use the simple pressurized storage design. The tank in the shop could absorb the bulk of boiler output while the tank in house could be slowly charge as a load.

gg

 

[nwomatt]

I will have 1000 gal pressurized storage right next to boiler in shop piped with 1.5" black iron then supply house with 1" thermopex. Hopefully that is big enough because its already buried. If I want to also add another storage tank in the house what type of tank and how big would I use there?

 

[goosegunner]

That is basically the Same set up that I have, distance to house is also similar. The storage in the house would really depend on your needs.

I do not have storage in my house but I will be adding it in the future. More as a buffer than anything. I would like to add my DHW to my system it would be more responsive with some storage near DHW connection. I also have forced air heat, so the buffer/storage tank could deplete the heat from the water and then replenish from the large storage in the shed. It should also make the forced air heat more responsive if you have hot water staged near the furnace instead of traveling the distance first.

You could also use the buffer/storage tank to supply low temp emmiters like your floor or some radiators. By depleting the buffer/storage in the house of useable btus it would help eliminate mixing of the large storage in your shed by always returning the coolest water to the storage tank bottom.

Now with all that some will post that you should have the boiler and storage in your house. I will agree that the heat loss will be in the home you are trying to heat. But it will also heat your shed that you want to heat. The mess will be out there as with the danger of losing the place you sleep.

In my case if it was all in my home it would be a problem heating my home in the summer when I am heating my pool with the boiler.

gg

 

[jebatty]

With regard to heating the house with a rad (water to air heat exchanger) in a forced air system, a lot is going to depend on the water temperature you need to provide the heat/comfort you want for your 2500 sq ft house. If you need 180F water, then storage for purposes of heating the house when you are not burning the boiler (Biomax or other) will not be of too much use because you will need pretty close to the maximum temp output of the boiler all the time to deliver 180F water. I assume maximum output temp will be in the 185-190F range. And if an assumption of 180F in and 160F out of the wahx (delta-T=20), then 1000 gal storage, heated to 190F, only has 10F available, which amounts to 83,400 btu's, which maybe is 1-2 hours from storage to meet the heat load for your house in cold weather, more of course in milder weather. You can adjust the numbers if your need is for less than 180F water to the wahx or based on your actual heat load.

This doesn't mean that storage will not be useful with regard to your shop or best operation of your boiler, and I nearly always agree that storage is essential with a gasification boiler, with 1000 gal being a generally useful planning objective.

A second consideration will be the 1" Thermopex. The Thermopex website indicates that the pex is CTS. The CTS pex pressure drop table I have shows pressure drop of 4.1psi/100' at 8 gpm and 6.2psi/100' at 10 gpm, which is getting pretty close to maximum flow in 1" pex. This translates to 9.43'/100' pump head at 8 gpm and 14.26'/100' head at 10 gpm, or 28.3' pump head at 8 gpm for your 300' round trip run of Themopex and 42.8' pump head at 10 gpm, both high head situations. At delta-T = 20, 8 gpm is 80,000 btuh and 10 gpm = 100,000 btuh. There will be additional pump head related to fittngs, interior piping, and the pressure drop in the wahx. You can use these numbers or adjust as appropriate when you determine your house heat load and dhw needs.

The fortunate point is with a wahx your need for gpm flow probably will be consistent as various emitters with different flow requirements will not be turning on and off. This means that you're in a good situation for parallel circulators to move that hot water between your boiler/storage and the house. By way of example, three 15-58's in series should meet or possible exceed somewhat the 8 gpm flow amount; or two 0012's or 0014's in series. You can look at pump curves for other options.

This all bring me back to my first post. First things first. 1) Determine your heat loss in all buildings to be heated; 2) determine gpm flow required and delta-T for each heated space based on heat loss; 3) determine size of supply/return piping between the boiler/storage and each heated space to carry the required gpm's; 4) determine pump head in each supply/return line and heat emiiters at required gpm's; 5) determine size of circulators needed to provide required gpm's at pump head. Now add -- 6) determine size of boiler and storage.

 

[Downeast Farmer]

This all bring me back to my first post. First things first. 1) Determine your heat loss in all buildings to be heated; 2) determine gpm flow required and delta-T for each heated space based on heat loss; 3) determine size of supply/return piping between the boiler/storage and each heated space to carry the required gpm's; 4) determine pump head in each supply/return line and heat emiiters at required gpm's; 5) determine size of circulators needed to provide required gpm's at pump head. Now add -- 6) determine size of boiler and storage.

I've been working through this process outlined by jebatty (and less specifically by others). It all hinges on that initial heat loss calculation, which is a fairly nebulous number (despite the concrete language of Manual J: infiltration can be the overwhelming determinant of heat loss, as anyone who has gone a visiting in Maine during the winter surely knows) and a moving one at that--like the bobber that got away and is now floating downriver. What I mean is this: my heat loss is going to vary by a factor of 2 over time as I work to lower it, a process that will take a few years.

You can finesse the boiler sizing issue within certain limits with storage--go ahead and size the boiler for today's heat loss and build fewer fires later as your loss lessens, if you've got enough storage.

Can you finesse the radiant distribution system in a similar way? Can you design the system to deliver the BTUs for the given delta T for today's heat loss and then just run the system at a lower temperature later?

You'd pay an economic cost for this way of proceeding (for having oversized the boiler and distribution system for the long-term average), but will have designed a system that addresses the heat loss over time.

Is there a better way to be approaching this question of system sizing?

 

[Tennman]

Hate that I'm on my iPad w/o a real keyboard. Read the BioMass sticky. I don't recall any dissatisfied Biomass owners and I'm one of the relatively early owners now in my 4th season. Certainly lots of green users but we all seem to eventually get on track with help from EKO owners. As far as the cost effective Eastern Europe produced boilers I'm glad I took a chance on the BioMass. Our 4800 sf home is heated with a 60 just fine but Ina much milder climate. I won't suggest a size for your area but I can tell you the BioMass 60 is an excellent unit for the price. You didn't mention the length of your underground run but with almost 95% certainty your 1" line is too small for the 60's output. To transfer the btu's/hr will require excessive velocity to get to your most likely energy transfer rate. I have 1 1/4 lines and my velocity is really less than ideal. I should have sprung for 1 1/2". That decision is costing me in paying for the amps to drive my 0013 pump. Stee is right regarding over sizing if you have storage. But if you get an 80 then you're really screwed with 1" lines.... Well I think your screwed now if you go with a 60. Go to the taco site and do the very simple math on sizing your pump. Quickly you'll see the effects of flow velocity and the resulting wall "friction" in the head loss calcs. I'm adding 1000 gal this summer finally. I've finally reached the point of burning well seasoned wood that the need for storage is apparent. Ok. I'm off to the next airport. If your interested I may be able to get someone to send my spreadsheet for sizing your pump. Just like doing a heat loss calc is very informative, understanding losses due to line size and things like elbows is invaluable. Wish I'd have done it before buying my pex. Realllly???? 40 below?? Is that on the Rankin or some other scale? If it got to -40F where I lived once in a while I'd have an 80.... Maybe a 100 -40! Yikes

 

[Floydian]

I've been working through this process outlined by jebatty (and less specifically by others). It all hinges on that initial heat loss calculation, which is a fairly nebulous number (despite the concrete language of Manual J: infiltration can be the overwhelming determinant of heat loss, as anyone who has gone a visiting in Maine during the winter surely knows) and a moving one at that--like the bobber that got away and is now floating downriver. What I mean is this: my heat loss is going to vary by a factor of 2 over time as I work to lower it, a process that will take a few years. You can finesse the boiler sizing issue within certain limits with storage--go ahead and size the boiler for today's heat loss and build fewer fires later as your loss lessens, if you've got enough storage. Can you finesse the radiant distribution system in a similar way? Can you design the system to deliver the BTUs for the given delta T for today's heat loss and then just run the system at a lower temperature later? You'd pay an economic cost for this way of proceeding (for having oversized the boiler and distribution system for the long-term average), but will have designed a system that addresses the heat loss over time. Is there a better way to be approaching this question of system sizing?

Hello Downeast Farmer,

You are thinking in the right direction here. Over sizing the boiler to the heat load is no problem with enough storage in the equation. Designing a system that can easily change supply temp is no problem either and planning for this from the get go is the way to do it, IMO. I am using a Grundfos Alpha with a Taco iValve(mixing valve) with outdoor reset and this type of control would be great with panel rads (or cast iron) with TRV's. You would simply lower the reset ratio on the ivalve as you lower your heat load over time.

Here is my setup: https://www.hearth.com/talk/threads/vedolux-37.101909/

As far as load calculations...you might consider a blower door test with IR imaging. This would give as close to a real world number on your air exchange rate as you can get. It would also show you the places in your house that you should address first. I recommend this site http://www.greenbuildingadvisor.com/ for helping plan your energy upgrades-the search bar is your friend!

And along those lines, how extensive do you plan on getting with these upgrades to the house? Do you see new windows and siding in your future?

Hope this helps,

Noah