HLF(heat loss factor)

Had to jump in on this. Stove is LL pioneer tv, power vent,just installed this year. Software 015. Originally i remember seeing HLF when scrolling through the setup menus, left it at ZERO, was going to set it to ONE to see what it did, (i might have, but don't think i did). Old house, no insulation in walls,some in attic, new windows and doors. Temps are set at 70 day, 72 for night(to get a bit more heat upstairs). When it goes to night mode, it kicks up a bit, fan usually comes on, room temp will go up to 74 or so, fan will keep running. I would think the fan should shut off once it sees the correct temp or slighty higher, maybe the software holds its settings and watches for further increases then it will kick back? It's not a problem anyway if 2 degrees overshoot is all it does(i can't tell unless i look at the thermometer). Now when i go to setup menus, i can not find the HLF setting! I know it was there. Can i unplug the network cable for 1 or 2 minutes to reset this?

Mozz, the HLF setting has the bug in V2 015. Use of anything but HLF 0 is discouraged.

From the sounds of it though you don't need to use it. 2 degrees of overshoot is to be expected when a setpoint change is made.

As for the fan, it will run whenever the feedrate is above 8 (if I remember right). It also has a delayed reaction compared to the feedrate, so it may take several minutes at 8 or higher feedrate before that fan is going to start turning. Likewise, it will take several minutes after the feedrate crosses back below 8 before the fan will stop turning. By several minutes I mean anywhere from 5 to 20 minutes depending on circumstances.

Lastly, the HLF setting should not be disappearing on you. Please check again and make sure you aren't skipping past it by mistake. I do this all the time, those three letter setting names start to blur together. Powering down and then up again shouldn't make a difference, but it can't hurt to try though.

gambler wrote:What exactly is the HLF setting on the coal-trol controlling? Is it the lag to lower the feed rate once the T-stat sees the set temp? In my house my T-stat is kind of far from the stove heat so it takes a while to get to temp and once it is at temp the feed rate drops but then it will become quite a bit cooler in the house before the stove responds. It just seems like a vicious cycle up and down and I think it would work better if the feed rate did not drop as fast or if the feed rate had a longer dwell at the higher feed once the T-stat saw the set temp.

( UPDATE )I talked to Neil the other day and we decide to try an experiment. Instead of running my portable fan and blowing the warm air out of the stove room I ran my furnace blower instead.He was thinking that I had an air movement issue and the T-stat was not seeing the temp change fast enough. With the HLF = 0 and the furnace fan running my upstairs bedrooms were a few degrees cooler than when I used the portable fan and the furnace fan did not wash as much heat out of the stove room as the portable fan and I still had a heat lag. Next I went back to my portable fan and a HLF=1 setting and things have been working great. Stove room is cooler and the upstairs bedrooms are warmer and I don't have that real long lag that I had before. I think part of my issue is that I have a lot of glass (doors and windows) on the front of my house plus my living room has a 14ft vaulted ceiling. With the HLF=1 setting I am totally happy with the performance of the coal-trol unit. And thanks to Paul and Neil for taking time from their busy schedule to talk with me and give me advice on using their product.

Scrolled through the menus, i just can not find the HLF setting, i know it was there. It goes TIME, DEG, MIN, MAX, IGN. FR. HLf and tbrn is gone. I can get into feed and test. Thinking of what i did before, the only thing is i changed the network cable to a 7 ft piece instead of the longer cable.

Um, I'm going to PM you on this. That is very odd.

Hyfire I with only the 90K burner running.

HLF = 0
Min = 6
max = 40

Doesn't seem to be hitting the setpoint on the setback settings in the morning. When it kicks up in the morning at 5am, it never reaches the setpoint by 6-6:30. Should it more than 1 degree difference? Maybe increase setpoint 2-3 degrees?

-or- Should I try increasing the Max feed to 45-50?

-or- change the HLF = 1

-or- light the 40K burner to give it more heat so it satisifies quicker.

It maintains nicely on Temp HOLD, maybe 1 degree overshoot.....

I don;t want to do too much if it is simple calibration fix.

Thanks guys!

All of those options should help it reach the new setpoint temp more quickly, however they all will also probably exacerbate any overshoot you see and thus mean more time before the control will settle on the new setpoint temperature.

With our control there is a tradeoff between time to settle, overshoot amount, and time to first hitting a setpoint temp. Increasing the BTU capability, either through increased MAX or increasing BTU capability with a second stoker, will shorten the 3rd time, but will very likely increase the first two. Increasing HLF can have the same effect.

So general rules of thumb:
- If you are seeing large overshoots (more than 3 degrees) when making a setpoint change then it may help to decrease your MAX setting and/or increase air circulation through the space being heated. This should have the effect of lowering overshoot amount, but will also increase time to setpoint and time to settle.

- If you are seeing little or no overshoot, but very long times until the setpoint is met (3+ hours) then it can help to either use a higher HLF setting (again only on V2 020 or higher), increase insulation factor in the heated space, light up the second stoker (if available), or increase MAX (being careful not to set it too high so that hot coals come of the end of the grate). Overshoot may increase, but 2-3 degrees of overshoot is probably an acceptable tradeoff for increased responsiveness.

- Increasing air circulation and easing heat transfer from the stove to the heated space is always a good idea. For a room stove that is heating a house, this can be difficult but it is vital to getting optimum performance too. For furnace supplement stoves and others tied into a central HVAC system that means either turning on the blower all the time or utilizing a limit switch setup that will kick on the blower when the plenum air reaches a certain temp.

- The more closely the heat source can be "coupled" to the space being heated the better. This means fans, floor registers, and better air and heat circulation for room stoves which heat a house. Central location for the stove can also help in this case. For furnaces and stoves in more or less unheated basements it means minimizing the impact the cold basement air has on the upstairs air being heated. Ducting is key, both heated air and cold air return. Cold air return should enter the stove's convection channel and/or heat jacket with a minimum of air mixing in from the basement. If this can not be avoided, then using constant blower air circulation is a must in order for the Coal-Trol to be able to best deal with the unseen temperature drop associated with the basement air coming into the system. In this case, even with constant air flow, the large cold air mass of the basement will act as a significant drag on the speed with which temperature changes can be made in the upstairs air. This can result in overshoots and long settling times that may only be able to be slightly improved by experimentation with HLF and MAX adjustments.

I do have Ver. 020
I will change the HLF =1 and see what happens tonight.
for now....and I raised max to 45 for a start.

Thanks for the input, probably help others out too!

I will try a few different options. Will post results.

This morning, it was right on the setpoint when I got up, I have it ramping up an hour before I get up! I think that did it.
HLF = 1
Min Feed = 6
Max Feed = 45
The temp going upstairs is 110-120 degrees in the pipe (about 4' from the stove).
Exhaust Temp = 175-200 Deg. (in the pipe)

it's not real cold out yet (26-30), so once it starts staying colder, will lite the other burner if needed.

Thanks!

Hi Dave, What time in the morning do you set your temp? I'm having the same problem others are not reaching set point when I get up. I keep making the set point time earlier & earlier in the morning. Are you reaching the set point temp at the time you set? EG if you set the time at 6 am & temp at 72 degrees does it reach that temp at 6am? I set mine at 4:30 am & I still don't reach set point at 6:30am. I raised max feed rate to 45 & HLF 1. I have ver. 2.021. Thanks.

I have both burners running now....and I changed my HLF = 2 and seems to do a bit better, I have it set at least an hour before I get up and it seems to reach it now. I only have a 2-3 degree difference (setback temps), it depends on your difference in temps.

SPC - How much are you changing the setpoint on your setback?

Seems to working good, it is getting really cold tonight (20 Degs), we will see how it does.

WNY wrote:SPC - How much are you changing the setpoint on your setback?

Thanks Dave, Mine is set at 72 at 4:30 am & 68 at 8 pm, 4 degrees.

Try a 2 or 3 degree swing and see if it gets to it...all the stuff that Paul V. mentioned, every house/heating is different....

I left mine on hold last night and it was great. It was 17 outside and the house was nice (also, put another stove in the attached garage and heating the upstairs now much better.)

Since coal heat is so steady and even in a stoker using the Coal-Trol I have found that it is more efficient to run the same temp day and night. When I first got the unit last year I experimented with setback temps, the savings in coal were minimal and the time it took to reheat the house and the resulting overshoot each day all but negated what I had saved by the lower set point at night.

As WNY suggested I would say that 2 degrees (3 max) would be all you want to set back at night. As has been posted (if you have the right firmware in the Tstat) you can play with the HLF to speed up the recovery from setback, but the resulting overshoot will run the temp at least 3 degrees above set point.

Of course every house is different and you just have to play for a little bit to accomplish operation the way you want it. The Col-Trol PID is set up for the slow responding stable nature of coal and those guys have done a great job trying to match all circumstances. Paul gave all the basic considerations for making adjustments and you will be able to improve the situation by following his advice.

My advice is to let the Coal-Trol and stoker combination do what it does best, keep your house at a stable temp (minimize or eliminate any night set back). I think you will find overall that it gives you the best use of your coal and doesn't cost any more than large differences in night setback.

This opinion in no way reflects the opinion of the Forum owner, its members or manufacturer's rep's.

Matthaus wrote:Since coal heat is so steady and even in a stoker using the Coal-Trol I have found that it is more efficient to run the same temp day and night. When I first got the unit last year I experimented with setback temps, the savings in coal were minimal and the time it took to reheat the house and the resulting overshoot each day all but negated what I had saved by the lower set point at night.

As WNY suggested I would say that 2 degrees (3 max) would be all you want to set back at night. As has been posted (if you have the right firmware in the Tstat) you can play with the HLF to speed up the recovery from setback, but the resulting overshoot will run the temp at least 3 degrees above set point.

Of course every house is different and you just have to play for a little bit to accomplish operation the way you want it. The Col-Trol PID is set up for the slow responding stable nature of coal and those guys have done a great job trying to match all circumstances. Paul gave all the basic considerations for making adjustments and you will be able to improve the situation by following his advice.

My advice is to let the Coal-Trol and stoker combination do what it does best, keep your house at a stable temp (minimize or eliminate any night set back). I think you will find overall that it gives you the best use of your coal and doesn't cost any more than large differences in night setback.

This opinion in no way reflects the opinion of the Forum owner, its members or manufacturer's rep's.

I tend to agree!