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[kybaseball]

Just kinda curious about this. I checked my stove and it was on 175 so I went back in to check the vent to see what the temp is coming out. I checked it and it was 136. Just curious to see what others may be getting out the vent. Thanks

[willieG]

temps out the vent may vary greatly..temps out the vent will change drastically depending on CFM you are moving..and to a smaller amount by what the temp of the air going over the heat exchanger is as heat transfer has a lot to do with the delta between the cold temp (the air being sent to the heat exchanger via the blower)  and the water temps in the  exchanger.  although it may be intersting to see how these temps vary  depending on type of furnace is in the home. i know my in home furnace is an "in ground water furnace" adn was designed to move  lots of air at low temps...it never goes off low speed (not sure of cfm) but my ductwork is huge. (my duct where my exchange is measures 24 x 14) i may just measure my heat output and post it for you and see what the difference might be

[jerkash]

My stove settings are 170-180 and my vent temp is around 110 degrees.  I have a 3-speed pump and run it on low

[jrider]

My stove settings are at 170-180.  When I sit my indoor thermometer on top of my vents, it usually reads about 95-96.  I'll be honest, I don't know much about heating but I have been very happy with the purchase of my OWB last year. 

[Scott7m]

Temp outside 170-175

Vent temp 115-120

[tree climber]

vent temp115 setings 170 160

[kybaseball]

My stove settings are 170-180 and my vent temp is around 110 degrees.  I have a 3-speed pump and run it on low

I also have a 3 speed pump but it is ran on high. Should I change that to low? Or what would change if I did move the speed to low or medium?

[Scott7m]

Leave on high, slowing the speed would increase delta T and we want that

[coondog1]

Man I am jealous  ...love this forum hopefully me and scottm7 can hook up after some tax money gets rolling .The electric and propane is eating me up ....

[Scott7m]

Man I am jealous  ...love this forum hopefully me and scottm7 can hook up after some tax money gets rolling .The electric and propane is eating me up ....

Yea...  This cold snap has people worrying about what the next bill is gonna look like.  There is nothing better than being warm as toast and know that it's not costing you out the wazoo

[willieG]

my  blower fan on my "water furnace" is in low speed (950 cfm so says owners manual) and my water temp from the OWB is between 170 and 175 as i take this readiing at the register...105.3

[horse62049]

I have did alot of checking on this i have a 3 speed water pump running on low was 119 medium 121 high 127 now u can go and change your blower speed on your furnace most have low medium and high changing the air speed along with water speed can make a big difference in temp I aim on high now tomorrow i aim going to go to medium and then low and see what temp difference is.I will up date with results tomorrow night

[creeker]

So... I take it is better to run the circulating pump at the highest setting vs. the low?  I run mine on low currently.

[Scott7m]

Hotter isn't always better, it just varies folks.  This is part of why each job is a design within itself and one pump might cover you but not the next guy.

There is numerous variables, line size, how many restrictions there may be, pump size, heat exchanger type... 

So there is no set answer, low may be fine, it just depends.

What we look for is a delta t around 20, that's the difference between supply side of coil vs return side, 180-160 is delta t of 20.  You may be heating your home fine on low, but if your gpm is to low, your return temps could be way to cold. 

Pump speed don't change efficiency really, your home requires the same # of btu, regardless of the heat source or pump size etc....    Higher pump speeds result in higher register temps, they also increase return temps,as the coil is at an average higher temp..

Sooooo....  With all that, set ups are just different, the only thing running a pump higher would hurt is probably just a bit more electric use by the pump, but if your system was designed to be run on low, it may be fine, most installers don't get to technical and a lot wouldn't know what delta t even is

[willieG]

as scott says the only thing you need be concerned with really is the return water temps to your OWB.  if your return water is lower than what your dealer tells you it should be you need to move water faster (or take less heat from it, and most of us don't want to do that)

if your return temps are high and your house is not heating good enough you need to take more heat from the water (bigger exchanger or faster blower or another heat source?)

if your house is heating and you are happy,  and the return water temp  is high enough  then who cares about the temp at the vent

heat at the vents is controlled by  many things (or a combination of things)  heat of incoming water...GPM being delivered...size of exchanger...CFM of air being moved...

as for your "delta" there is nothing set in stone that is has to be 20 degrees, that is just an industry standard that is used as a target in most cases as it is also easy to work with when counting btu's. if your delta is 10 or 25 as long as yoru sytsem can maintain the  proper return temps and can recover it should be fine

i know they say a delta that is more than 20 may increase fuel usage but we are burningn wood, i would try and tweak my sytem to get to that target i guess, but i wouldn't lose any sleep over it