Question about nozzle size and my Hydrostat high/low settings.

chowchow

Hello my burner motor takes a .90-80B nozzle thats what came with the Beckett system i have. What would be some reasons a HVAC man might change the nozzle to a different size? Would they change from a solid to hollow? Or from .90 to .65 would this use less oil? Or from 80B to 70B just say. Im wondering if i put in a different nozzle will i use less oil. Also part 2 is my Hydrostat i have set at 140 low and 170 high with a 10 differential, now the 10 diff cant be changed with the current set up i have. So i just was wondering is 140 low and 170 high a good setting for optimal oil consumption or should i set the low to 130 and the high to 180? Any help is greatly appreciated. And i must say i have been on many message boards and this is by far the most helpful and knowledgeable one ive been on. Thanks.

Jamie Hall

The important thing to remember is that the oil consumption isn't controlled by the nozzle, at least not directly, but by the heat loss of the structure and the efficiency of the boiler. A smaller nozzle, all else equal, will simply cause the boiler to run longer to heat the house.

Now the choice of nozzle is made by trying to get the best -- most efficient and cleanest -- combustion out of your particular boiler setup. A really good oil person may try different nozzles or patterns to make sure that the chosen one produces the best results in your situation. He or she may also choose a smaller one in some cases, if it produces good combustion, if the boiler is bigger than it needs to be for the structure -- but there are limitations on that.

HVACNUT

Some boilers offer multiple firing rates.
What make and model is the boiler?
What make and model is the burner.
What is making hot water, a tankless coil in the boiler, or an indirect water heater? 

chowchow

Ita a Peerless WBV-03 and the beckett came with the unit already and the Hydrostat. I have a tankless coil. Anyone have any answers to my Hydrostat question? Thanks for replys. Also can you switch from a solid nozzle to a hollow?

SuperTech

I have a WBV-03 without a tankless coil and use a .75 80B. With a tankless coil I would probably stick with a .85 80B since it's easier to find than a .90 80B.

Your settings are OK. I usually see the low anywhere from 140-160⁰, high 170-190⁰. Hopefully you have a thermostatic mixing valve on the coil. If you do I would set the low limit for 160⁰ for a little more hot water capacity. 

chowchow

Yes the .90-80B is very hard to find i looked for a while and finally found 2 that had to be shipped from kentucky home-depot not a common nozzle. So if i set to 160 low then put to 190 high? Also can you go from a solid nozzle to a hollow one? Whats the purpose of a hollow and a solid nozzle, what do they do thats different is it the spray pattern?

EBEBRATT-Ed

@chowchow

Set the high limit to 190. This may keep the boiler from cyclin on high limit. 190 will give you an average baseboard temp of 180 which is normal. The boiler will only get to 190 if you have less baseboard installed that the boilers capacity.

The low limit determines the tankless water temp. Set it as low as possible to still be able to get enough domestic hot water you will have to play with it.

130 is probably too low and 160 may be too high. It depends on your water usage. Adjust it 5 degrees at a time till you find the sweet spot.

EdTheHeaterMan

The spray pattern of a nozzle should be matched to the air pattern from the burner. On older oil burners (pre 1960 models) that do not have the flame retention design of your Beckett burner, Burner service personnel were trained to look at the shape of the combustion chamber and the air handling parts of the burner. By matching the oil particles to where the air firm the burner ends up in the fire box, You can get a clean (smoke free) flame with less excess air.

The flame retention air pattern makes the oil droplets move to conform with the high velocity air pattern. It actually causes the oil droplets to follow into a low pressure area right next to the turbulator and get caught up in the air pattern that causes the flame to burn within 1/8" of the turbulator. That is called "flame retention" because the flame looks like it is retained on the actual turbulator.

So, if the higher velocity air is moving the oil droplets out of the actual spray pattern, why does it matter if one uses a 45° or 60° or even a 90° angle? And what does the solid or hollow spray pattern do for the flame? Basically it is the same idea. There are 3 air patterns in every flame retention burner design. The center hole where the oil spray is introduced is the primary air that picks up the oil. The slots in the flame retention ring enter the chamber at a lower pressure in a swirling pattern that causes the oil to circle back to that lower pressure area and get caught up in the swirling air pattern. This is the most efficient and hottest way to burn oil. If that is all the air that is needed for complete combustion then the burner's job is done. That might be on firing rates lower than .75 GPH.

If the nozzle is introducing more oil than the primary and secondary air offers, the excess oil will need additional air from the burner. That is where the third air outlets come in. Those oil droplets that burn further out in the chamber will use the third air flow opening. That happens around the outside of the retention ring. The more fuel the larger the opening.

Depending on how that air pattern ends up inside a combustion chamber will determine what GPH, angle and patterns works best in any particular boiler or furnace. It is all figured out by the manufacturer during R & D testing. Why the .85 45° nozzle work better in the Weil McLain WGO boiler when the same burner uses a .85 80° nozzle in a Burnham boiler all depends on the way the air and oil move in the firebox or that particular appliance.

So when a technician selects a nozzle that is different from the previous one or the one that came with the burner, they may have a good reason OR it might just be that they did not have the right one with them on the truck. SO... once you find the best nozzle for your system. Then purchase a box of them for future use.

EdTheHeaterMan

As far as setting the temperatures on your HydroStat, the lower the temperature the better. So if 165° high limit gets you sufficient heat on the coldest day of the year, there is no need to set it any higher. If 140° low setting gets you in a place where you have enough hot water, there is no need to set it any higher.

The hotter temperatures will just make the heater loose heat faster. The higher the temperature difference is between the hot water in the boiler and the air that is outside the boiler and traveling thru the boiler, up the chimney, when it is not operating, the greater the heat transfer losses will be.

The boiler is always getting cooler when ever it is not firing. 190° boiler temperature metal will transfer more heat to 70° basement or boiler room air that 140° boiler metal temperature will. It is a fact of the laws of thermodynamics. That is a law you can't break no matter how hard you try. In laymen's terms: hot goes to cold . The more hot you have the more it will move to cold. So keeping the boiler colder will always use less fuel in the long run. Any hot water that is not used for showering or room comfort etc. is wasted energy. Once you find the lowest possible boiler temperature that keeps you comfortable, that is the temperature settings you want to keep.

chowchow

EdTheHeaterMan said:

As far as setting the temperatures on your HydroStat, the lower the temperature the better. So if 165° high limit gets you sufficient heat on the coldest day of the year, there is no need to set it any higher. If 140° low setting gets you in a place where you have enough hot water, there is no need to set it any higher.

The hotter temperatures will just make the heater loose heat faster. The higher the temperature difference is between the hot water in the boiler and the air that is outside the boiler and traveling thru the boiler, up the chimney, when it is not operating, the greater the heat transfer losses will be.

The boiler is always getting cooler when ever it is not firing. 190° boiler temperature metal will transfer more heat to 70° basement or boiler room air that 140° boiler metal temperature will. It is a fact of the laws of thermodynamics. That is a law you can't break no matter how hard you try. In laymen's terms: hot goes to cold . The more hot you have the more it will move to cold. So keeping the boiler colder will always use less fuel in the long run. Any hot water that is not used for showering or room comfort etc. is wasted energy. Once you find the lowest possible boiler temperature that keeps you comfortable, that is the temperature settings you want to keep.

So i have had it at 140 low and 170 high for about 14 months and i get enough heat and hot water so should i just leave it? Some are saying to put up to 190, and a low of 160 it gets confusing with different opinions? Now i cant change my differential on my hydrostat its set at 10 for my set up, now if i could change it would that give me better performance/less oil usage?

chowchow

Thanks to all who put in their 2 cents.

HVACNUT

The boiler settings are fine. Leave it where you have it.
You realize you can't take full advantage of the Hydrostat when using a tankless coil. You can't use the economy setting, and you can't set it up for cold start like you could if it had an indirect water heater. 

As far as firing rate, the WBV-3 offers two with the Beckett AFG.The lower firing rate is shown with a different air tube, head, and using the Low Fire Baffle. 
A tech might be able to install a .75 nozzle @ 140 psi for a .89 GPH input with your setup. We used to use a .75 80°A with a low fire baffle and an F6 head on the Peerless JOT-3 because the flue passages were so tight.
As long as the tech is able to achieve proper draft, a 0 smoke, and all combustion within range. It might take some T&E to get it right, but if you're willing to pay for their time, then go for it.

chowchow

HVACNUT said:

The boiler settings are fine. Leave it where you have it.
You realize you can't take full advantage of the Hydrostat when using a tankless coil. You can't use the economy setting, and you can't set it up for cold start like you could if it had an indirect water heater. 

As far as firing rate, the WBV-3 offers two with the Beckett AFG.The lower firing rate is shown with a different air tube, head, and using the Low Fire Baffle. 
A tech might be able to install a .75 nozzle @ 140 psi for a .89 GPH input with your setup. We used to use a .75 80°A with a low fire baffle and an F6 head on the Peerless JOT-3 because the flue passages were so tight.
As long as the tech is able to achieve proper draft, a 0 smoke, and all combustion within range. It might take some T&E to get it right, but if you're willing to pay for their time, then go for it.

Thanks HVAC.

EdTheHeaterMan

Regarding smaller firing rate. It is a well known fact that shorter cycles are less efficient than longer cycles. That is because it can take as long as 5 minutes for a burner to reach its most efficient operating condition. The colder metal of the combustion chamber makes the oil droplets evaporate slower. This results in colder fire. Some of the oil droplets may even fail to burn completely and cause carbon particles we call smoke. The hotter metal and chamber parts of the appliance will reflect heat back onto the flame improving the droplet evaporation into a burnable fuel. If this process takes 3 or 4 or 5 minutes and the burner cycles off 2 or 3 minutes, then the highest efficiency burn is never really achieved.

If a smaller firing rate can increase the run time by just 30 seconds on each cycle, then that can mean as much as 50+ hours of more efficient operation every season. If it can result in 5 minute longer operation every cycle, then there will be less off cycles per hour and more higher efficient run time per cycle. This could mean hundreds of higher efficiency hours of operation each year. also less wear and tear on the operating parts like limit controls and burner relays and motors.

EdTheHeaterMan

chowchow said:

So i have had it at 140 low and 170 high for about 14 months and i get enough heat and hot water so should i just leave it? Some are saying to put up to 190, and a low of 160 it gets confusing with different opinions? Now i cant change my differential on my hydrostat its set at 10 for my set up, now if i could change it would that give me better performance/less oil usage?

Leave it where it is if you have comfort and hot water to your satisfaction. If you want to get bold, you can try setting high limit to 165° or even 160° if you want to test the limits of your system. What will happen? Nothing! You will not notice any difference because at that lower temperature the radiators will just take a little longer to heat the rooms and satisfy the thermostat. (and longer cycles are good). The only difference might happen when it gets very cold outside. If you notice that when the outside temperature drops below a certain number the thermostat can no longer keep up, that is because 160° radiators do not put enough heat in the home fast enough to keep up with how fast the heat is leaving the house.

Here is an example. @ 160° your radiator might have a heating capacity of 480 BTU/h and a 10 ft radiator will then give off 4800 BTU/h.

If your room needs 5200 BTU/h on the coldest day of the year, then the temperature in that room will be fine until the outdoor temperature drops to say 16°F. from that point on the radiator will put out the same amount of heat and the circulator pump will run non stop. as the temperature drops to 15° then 14° the indoor temperature will drop from the 70° thermostat setting down to 69° the 68° and so on as the outdoor temperature drops. This is when you will discover that 160° radiator temperatue is insuffifient,

At that time you can increase the radiator temperature by setting the high limit to 160° and the problem will be solved. The same radiator with 165° water might have an output of 5000 BTU/h or maybe 5200 BTU/h at 170°. When the installer sets up your system, he does not know how the water temperature in the radiators will react on the coldest day of the year. He can only guess that if it worked with the old boiler or old control, that it should be fine wit the new control if set at the same setting. If he does not get a service call after the control was installed "Not enough heat" then they are done and a job well done. No additional service needed. If he gets that service call during a very cold event, then all he needs to do is to adjust the temperature on the limit 10° higher and apologize for the mistake of setting the limit too low.

As far as the adjustable differential on the low limit is concerned, I always set that at 10°. That is for hot water priority (leaving the space heating circulator off if the boiler water is too low to offer enough heat for the DHW coil). That will not effect the burner cycles during a call for hot water.

chowchow

EdTheHeaterMan said:

chowchow said:

So i have had it at 140 low and 170 high for about 14 months and i get enough heat and hot water so should i just leave it? Some are saying to put up to 190, and a low of 160 it gets confusing with different opinions? Now i cant change my differential on my hydrostat its set at 10 for my set up, now if i could change it would that give me better performance/less oil usage?

Leave it where it is if you have comfort and hot water to your satisfaction. If you want to get bold, you can try setting high limit to 165° or even 160° if you want to test the limits of your system. What will happen? Nothing! You will not notice any difference because at that lower temperature the radiators will just take a little longer to heat the rooms and satisfy the thermostat. (and longer cycles are good). The only difference might happen when it gets very cold outside. If you notice that when the outside temperature drops below a certain number the thermostat can no longer keep up, that is because 160° radiators do not put enough heat in the home fast enough to keep up with how fast the heat is leaving the house.

Here is an example. @ 160° your radiator might have a heating capacity of 480 BTU/h and a 10 ft radiator will then give off 4800 BTU/h.

If your room needs 5200 BTU/h on the coldest day of the year, then the temperature in that room will be fine until the outdoor temperature drops to say 16°F. from that point on the radiator will put out the same amount of heat and the circulator pump will run non stop. as the temperature drops to 15° then 14° the indoor temperature will drop from the 70° thermostat setting down to 69° the 68° and so on as the outdoor temperature drops. This is when you will discover that 160° radiator temperatue is insuffifient,

At that time you can increase the radiator temperature by setting the high limit to 160° and the problem will be solved. The same radiator with 165° water might have an output of 5000 BTU/h or maybe 5200 BTU/h at 170°. When the installer sets up your system, he does not know how the water temperature in the radiators will react on the coldest day of the year. He can only guess that if it worked with the old boiler or old control, that it should be fine wit the new control if set at the same setting. If he does not get a service call after the control was installed "Not enough heat" then they are done and a job well done. No additional service needed. If he gets that service call during a very cold event, then all he needs to do is to adjust the temperature on the limit 10° higher and apologize for the mistake of setting the limit too low.

As far as the adjustable differential on the low limit is concerned, I always set that at 10°. That is for hot water priority (leaving the space heating circulator off if the boiler water is too low to offer enough heat for the DHW coil). That will not effect the burner cycles during a call for hot water.

Now Ed let me ask you this in april/may when the weather starts getting warm will i use less oil if i set the Hydrostat to 130 low and 160 high? I usually leave it at where it is year round at 140L/170H but i turn both my thermostats down to 45 degrees F during the spring and summer months to use less oil,what do you think? Just want to hear what temps you would set the H/L at and the thermostats thanks for your time.

MikeAmann

When the weather warms up and you are no longer calling for heat, the 170* hi limit is taken of operation automatically. Your wall thermostats control that function. Think of it this way..... the HI limit and the LO limit are actually both high limits, just one is set to a lower temperature. HL / LL is NOT a window. Summer - no calls for heat - you operate off of the LO limit. Winter - thermostat calls for heat - you operate off of the HI limit. Get it? Set the LL to whatever temp meets your DHW needs.

chowchow

MikeAmann said:

When the weather warms up and you are no longer calling for heat, the 170* hi limit is taken of operation automatically. Your wall thermostats control that function. Think of it this way..... the HI limit and the LO limit are actually both high limits, just one is set to a lower temperature. HL / LL is NOT a window. Summer - no calls for heat - you operate off of the LO limit. Winter - thermostat calls for heat - you operate off of the HI limit. Get it? Set the LL to whatever temp meets your DHW needs.

Thanks mike. So in the summer if i operate off the LO limit setting, 140 is ok, do you think it would be better to lower it or just leave it alone?