Baseboard in closet


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Old 09-23-07, 08:21 PM
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Baseboard in closet

I'm in the process of converting my breezway to be a mudroom/ part of my house and part of this includes heating the space

I'm adding an 8ft section of baseboard in the room but unfortunatly about 2 feet of it will be covered or I should say inside the closet i'm building on one end of the room.

Has anyone ever had to do anything like this? Any suggestions?

I was kinda looking forward to warm toasty jackets but I don't really want to lose needed btu's to heat the room.
 
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Old 09-24-07, 03:16 PM
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Have you done a heat loss analysis on the room to determine how many BTU's you need to heat it ? That's really the first step. Then, you need to know if the boiler has the extra capacity to supply the BTU's you need (most are oversized, so might not be an issue.) If you will be tapping into an existing heating circuit to supply the hot h2o for the new baseboard, will the rooms downstream of the new bb suffer from having cooler water flowing into their respective bb's ?

How big is the room ? Windows / doors / outside walls / amount of insulation , etc all come into the heat loss calculation.
 
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Old 09-24-07, 07:57 PM
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Originally Posted by NJ Trooper
Have you done a heat loss analysis on the room to determine how many BTU's you need to heat it ? That's really the first step. Then, you need to know if the boiler has the extra capacity to supply the BTU's you need (most are oversized, so might not be an issue.) If you will be tapping into an existing heating circuit to supply the hot h2o for the new baseboard, will the rooms downstream of the new bb suffer from having cooler water flowing into their respective bb's ?

How big is the room ? Windows / doors / outside walls / amount of insulation , etc all come into the heat loss calculation.

Actually where I'm tapping in is at the end of the line so i won't be affecting other rooms.

My boiler can handle the extra btu draw (it's way oversized)

I did do a heat loss calc and I can get away with what 6-8 feet will put out so due to this closet issue i'm going to go with the 6 footer cuz it's only the mudroom and i don't want it to hot.


The one thing I am concered about though is if my taco 05 circ pump will handle the zillion 90's i have to put in for this add. I guess i can wait and see and swap to the 07 if need be unless anyone has any ideas?
 
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Old 09-25-07, 02:58 PM
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See if you can find long sweep 90's ... or even make yer own out of a standard 45 and a street 45 ... if you add a bunch of restriction, the whole loop will suffer becuz the water will be moving slower. You might consider piping with PEX also, and not use all them restrictions.

Are you currently running appx 20* delta on the existing loop ?

Look at the Grundfos 15-58 superbrute as a replacement if you find it necessary to do so. Three speeds, so you can tailor to your needs. Medium is appx equal to the 007 Taco, although I understand that Taco recently redesigned the 007 and the new design has a much flatter pump curve.
 
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Old 09-25-07, 04:26 PM
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You may be able to use soft-drawn (bendable) copper and a minimum of hard-drawn 90s. Or, you could use larger size 90s adapting them to the existing piping.
 
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Old 09-25-07, 07:47 PM
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Originally Posted by NJ Trooper
Are you currently running appx 20* delta on the existing loop ?

Not sure what you mean here?
 
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Old 09-25-07, 08:33 PM
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Also why does the taco 5 on the taco website say 0-18 gpm


Is it adjustable somehow?

The 07 is only 2 more gpm at 20 so that probably wouldn't make a big difference.

I'm really not sure how I'm going to know if have enough flow.
 
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Old 09-26-07, 08:24 AM
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The flow of a pump is dependent on how much resistance to flow there is. If there are next to no restrictions then it will flow 18 gpm. Pumps have curves where as the head (resistance) decreases, the flow increases. The system has it's own curve - overlap them and it looks like a supply demand curve intersection. I'm not so sure I explained that very well...
 
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Old 09-26-07, 03:17 PM
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What seems simple at first, isn't ...

Let's start with a few basics.

Most boiler systems are set up to run a recommended 'delta T' of 20*F.

This means the water coming back to the boiler ideally will be 20* cooler than the water leaving.

The piping has a recommended flow rate for a few reasons. You don't really want to _hear_ the water flowing in the heat pipes, and don't want excessive flow scouring the inside of the pipe and causing erosion, and eventually leaks.

In the case of 3/4" pipe, the recommended flow rate is 4 GPM.

In order to attain the 20*F delta (difference), for every GPM of flow, you would need to remove 10,000 BTU of heat from the water.

So, if you had 4 GPM flowing, then ideally, you would want to remove 40,000 BTU from that water before returning it to the boiler 20*F cooler than it left.

Let's say you were using fin tube baseboard rated at 600 BTU per lineal foot. If you divide your theoretical 40,000 BTU by 600, you come up with 66 feet of baseboard.

I know this seems like a lot of knowledge that you don't need to know, but it may help clear some fog... continuing ...

Every piece of straight pipe, and every fitting adds restriction to the system. This restriction is called HEAD .

System designers add all these restrictions up, and using pump curves select a pump that will generate the design flow for the system.

How do you know if you have enough / too little flow ?

Look at your existing design. Add up how many feet of baseboard is on the loop. Multiply that by 600. That is going to tell you how many BTU you need to pump into that loop to achieve a 20*F delta. Divide that by 10,000 . That will tell you how many GPM you need to flow in that loop.

You could go around and count all the 90s, 45s, etc, and add them all up to come up with a precise 'total equivalent length', but you can use a 'rule of thumb' here. Take the TOTAL length of the loop in feet, baseboards and all connecting piping, and multiply by 1.5 .

Now, another 'rule of thumb' : To arrive at PUMP HEAD, multiply the total length from above by .04 . That's 4 feet of pump head for every 100 feet of total length.

Take that number to your pump curve chart and select a circulator that will do the job.

ALL THAT SAID:

If your system is well designed to start with, adding 8' of baseboard will likely not change things enough to cause any real problems. BUT, you DO want to minimize the 'knots' you put in the piping to connect that baseboard by keeping the run as 'smooth' as possible.

Sorry for the long post...
 
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Old 09-27-07, 08:35 PM
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Originally Posted by NJ Trooper
What seems simple at first, isn't ...

Let's start with a few basics.

Most boiler systems are set up to run a recommended 'delta T' of 20*F.

This means the water coming back to the boiler ideally will be 20* cooler than the water leaving.

The piping has a recommended flow rate for a few reasons. You don't really want to _hear_ the water flowing in the heat pipes, and don't want excessive flow scouring the inside of the pipe and causing erosion, and eventually leaks.

In the case of 3/4" pipe, the recommended flow rate is 4 GPM.

In order to attain the 20*F delta (difference), for every GPM of flow, you would need to remove 10,000 BTU of heat from the water.

So, if you had 4 GPM flowing, then ideally, you would want to remove 40,000 BTU from that water before returning it to the boiler 20*F cooler than it left.

Let's say you were using fin tube baseboard rated at 600 BTU per lineal foot. If you divide your theoretical 40,000 BTU by 600, you come up with 66 feet of baseboard.

I know this seems like a lot of knowledge that you don't need to know, but it may help clear some fog... continuing ...

Every piece of straight pipe, and every fitting adds restriction to the system. This restriction is called HEAD .

System designers add all these restrictions up, and using pump curves select a pump that will generate the design flow for the system.

How do you know if you have enough / too little flow ?

Look at your existing design. Add up how many feet of baseboard is on the loop. Multiply that by 600. That is going to tell you how many BTU you need to pump into that loop to achieve a 20*F delta. Divide that by 10,000 . That will tell you how many GPM you need to flow in that loop.

You could go around and count all the 90s, 45s, etc, and add them all up to come up with a precise 'total equivalent length', but you can use a 'rule of thumb' here. Take the TOTAL length of the loop in feet, baseboards and all connecting piping, and multiply by 1.5 .

Now, another 'rule of thumb' : To arrive at PUMP HEAD, multiply the total length from above by .04 . That's 4 feet of pump head for every 100 feet of total length.

Take that number to your pump curve chart and select a circulator that will do the job.

ALL THAT SAID:

If your system is well designed to start with, adding 8' of baseboard will likely not change things enough to cause any real problems. BUT, you DO want to minimize the 'knots' you put in the piping to connect that baseboard by keeping the run as 'smooth' as possible.

Sorry for the long post...

Wow dude you really know alot about this stuff huh. I didn't realize how involved these calculations are.

Anyways I'm going to measure up what I got and post back. Thanks.
 
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Old 09-27-07, 09:25 PM
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I learned everything I know from these fine gentlemen right here on this board... took me a couple years, maybe in 25 or 30 years I'll know ALMOST as much as they do !
 
 

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