# Condensing oil fired boiler



## Morning Wood (Jan 12, 2008)

Is there anything out there yet that is a good reliable unit. I've got to make a choice on a boiler soon. It's either propane or oil. Everyone I've talked to says the oil technology just isn't here yet. But the price of propane is scary. Also, maintenance costs are a factor to consider. Only looking at condensing units? Any thoughts? Thanks, Nick.


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## Morning Wood (Jan 12, 2008)

Wow. No one. Should I try to HVAC section?


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## Jackfre (Mar 1, 2012)

*BAck in the mid-80's*

Back in the mid-80's I represented a company which made a condensing oil furnace. Ultimately, it put them out of business. To bad, as they were good folks, but they put the product out to general sales rather than strict certification of the installers prior to buying. 

Net/net the service requirement is just to great. Savings are eaten up by component failure and cleaning costs. Ph of the condensate is in the 2.6 range vs gas' 3.1. 

IMHO, your best bet is to buy a large lp tank rather than have the company supply a smaller tank. That lets you get over the heating season, depending upon your heat loads, and not have to be buying mid-season. I'm starting a remodel soon and will be installing a 1000 gallon tank to replace my current 250.

Oil has 140ktu/gal where lp has 92kbtu. On the face of it, oil would win, but 100 times out of 100 I would go with a gas fired modcon boiler with a good outdoor reset system and be done with it. You will gain about 10-12% efficiency gain over the oil unit and the benefit of modulation will save you about 30% and make you more comfortable.

The real issue with oil is that it is kind of a boutique fuel. 80% of the oil sold for residential heating is in the greater northeast. Major manuf look at development costs of a product and say, "Gee, I can spend X$ developing a new high efficiency gas unit or heat pump that will sell all over the country or I can spend the same X$ on an oil fired unit I can sell in the northeast". The product development costs do not work out.

There are other things you can add to your home to reduce your overall heating bill, minimize oil consumption and save money. is your current oil boiler in decent condition?


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## Morning Wood (Jan 12, 2008)

I am adding an 2k square ft addition to my house and gutting the existing 1k square ft house. Existing boiler is going bye bye. Burnham with beckett burner. it is probably from the 80's. 3k square ft total when all said and done. Peak design load is about 50k btu's for the house. Double wall construction, lots of insulation everywhere, lots of attention to air sealing, air recovery unit, etc. Defintely going wall mounted modulating condensing boiler. Was decided on the Buderus GB142, but thought I might consider oil one more time or a different gas fired manufacturer like triangle tube. The buderus comes with the manifold already assembled so there is quite a bit of savings right there.


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## Jackfre (Mar 1, 2012)

Buderus is a good unit as is the Triangle Tube. I would put the Rinnai against either of them. It too comes with the low loss header and is a SS hx. I'm biased as I represented them in New England for 21 yrs. I would suggest you look into mini-split heat pumps for cooling and dehu. Don't oversize them in Cape Ann (lovely area) as you will need dehu more than cooling there. What is your distribution system?


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## Morning Wood (Jan 12, 2008)

Radiant hydronic in living spaces. Baseboard in bedrooms. We are seriously considering Mitsubishi mini splits, which may get rid of baseboard in the bedrooms. Putting in the smallest head units possible. I think we only require like a 2 ton system which is impossible to accomplish with the floor plan. They will be used mostly for ac and dehumidifying, but may be used for heat too if the radiant can't jump back quick enough on warm sunny days. I will look at the Rinnai and ask my plumber about it.


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## Jackfre (Mar 1, 2012)

*Look at Fujitsu too*

Again, my bias is noted as I represented them for 12 yrs in New England.
What I did with the mini-splits was to put a multi unit in the bedrooms and put the highest efficiency 12 (25 seer/12hspf) unit in the primary living area. I run the ms downstairs with my Rinnai Energysaver to heat the first floor. The upstairs unit hardly ever run.

It is a good idea to have alternate heat in conjunction with your radiant. The lead/lag issues with radiant mean it is best when the system has a load against it, even with the most precisely programmed ODR system. In Sept, most of Oct and even into Nov as well as April, may early June you will not want to run the boiler but will have no problem running the ms


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## Morning Wood (Jan 12, 2008)

The way the house is laid out we will have two outdoor condensers. One will run our master and main living space and the other will end up running one of those small ducted head units and probably another small unit for the rest of the downstairs. Not ideal, but the way it has to be. I looked at the Rinnai, and it doesn't seem to modulate down very far on propane. Everywhere is granite and ledge, so burying a tank is going to be costly, but I like the idea of owning a tank.


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## Jackfre (Mar 1, 2012)

In MA I believe the max oil storage is two 330 gallon tanks. I was on the NFPA 31 Committee for about 15 yrs and there was discussion of allowing double that, but check with your local ahj and your oil supplier. If I was going to have a lot of storage of #2 I'd build a bunker to hold it in the event of a leak. If you decide to go oil, just get a Buderus and a Riello cast iron and service it properly and you will hit the low to mid 80's. Drop an indirect off the boiler and you will be set. Get the best ODR unit you can. Buderus has their own. Pricey, but worth it. Run your mini-splits as much as you can and you can get 80% of our heating with them. Again, I would try to put the bedrooms on one multi. Line set lengths are quite liberal. Try to lay it out that way. The multi's are not as efficient as the single heads. Make sure you use the Air-Tec wall mounting brackets to support the condensers. You want them way off the ground.


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## Splinter (Apr 5, 2005)

http://www.viessmann.com/com/en/products/Oil_fired_boilers.html

I have a natural gas Viessman condensing boiler... Easy setup, works great... It was a bit warmer this winter, but my gas usage was 35% lower than last year. (avg 9 degree difference last year to this year)


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