nozzle choice - Peerless WBV-3 with Beckett

Local HVAC guy recommended this boiler and burner, with a .85gph nozzle on the Beckett, AFUE 86.2%.

Peerless lit shows it can also use a .60gph nozzle if using a Riello F-3 (or even 1.10gph on a Beckett). Riello with .60 shows AFUE 87.5%.

As I have a *small* need (under 100K btu), wouldn't using a .65 nozzle be the choice?

I'd think a smaller nozzle would use less fuel and thus the .85 would be wasteful and/or overkill. How do you choose a nozzle and burner?

Thanks.
Tom

 

Your heat loss will dictate which nozzle should be used in a boiler with multiple firing rates.

 

Thanks Grady. The S/F calculator shows an 18,000 btu/hr loss. It's a small house, around 1000 sq ft living space.

How do I figure nozzle for that heat loss? Is there a chart or calculator somewhere I can use?

Thanks.
Tom

 

I am assuming you are talking about a Peerless 3 section boiler?

It sounds like you will be using the lowest firing rate allowed by the manufacturer. Be aware, as a oil heating tech, that the smaller the nozzle below .85 increases your probability of problems as the hole in the nozzle gets smaller and easier to plug up. I would never go lower than a ..60 nozzle as I have had many problems. If you are going to use the .65 nozzle, it is best to have 2 oil filters, one standard at the tank, and one "spin in" type at the burner.

The .65 nozzle is a little more efficient and will cause the boiler to start/stop or cycle less often. The firing rate is also determined by the oil pump pressure. Nozzles firing rates are based on 100psi delivered from the oil pump, but most oil pumps today are coming set at 140psi and many older pumps have been reset, as it was found to solve some burner problems. So a .65 nozzle at 140psi is approx. equivalent to a .85 nozzle. I don't have my chart with me.

The spray angle and spray pattern are determined by the combustion chamber size and configuration. Follow manufacturers specs for those.

 

Yep - WBV-3 Peerless 3 section. With my small house (1000 sqft), that's the smallest the HVAC guys around here recommend.

Excellent suggestion.

The Beckett and Riello burner pumps show 100psi, so I'm assuming the .65 nozzle really gives .65gph.

Again, many thanks. As the .65 at 100psi is more efficient, as you say, sounds like I'm better off using a Riello-3 with .65 nozzle than the Beckett at .85.

Tom

 

Bear in mind, Riello burners are not as well known and you may find a harder time finding a service tech for one in your area.

Also, I think they show the pumps at 100psi, on the brochures, but when they arrive, they are set at 140psi. There will be something to advise you when the burner arrives.

 

Thanks Mark. Is my assumption pretty much correct? With my relatively small btu need (small house, etc.), the smaller nozzle gives a slight increase in efficiency? I learned from a Beckett tech that I can use the .65 on the Beckett (instead of a Riello).

In other words, with my needs, the Beckett burner with a .65 nozzle is a better choice for me than the same Beckett with a .85?

Thanks.
Tom

 

Yes, the smaller nozzle should be more efficient, because less temp going up the chimney.
Riello burners are good burners, but go with Beckett if you are going to have nobody in your area to service them.

FYI - nozzle sizes are suggested sizes from the manufacturer. It does not mean that you cannot stray from the recommendation.

 

I was just looking at the nozzle specs for the WBV-03. With a Riello F3 you can use a .50 nozzle at 145# of pump pressure to yield an input of about .60gph. The smallest recommended nozzle with the Beckett is .75 @ 140#. This would give you an input of +/-.90 gph. The smallest nozzle used with a Carlin burner is .65 @ 150# giving an input of +/-.80 gph. With your minimal heat loss, the Riello would be your best bet but as Mark said, fuel filtration with the small nozzles is critical. Riello burners are "different" so if you do opt for the Riello, just make sure your service company is comfortable with them. More & more companies are using them all the time.