Questions on Pellet Boiler for New Home Build

[BoilerMan]

I think ledge is site specific, or regional specific. I have no earthworking experience in other parts of the country. Around here, we have "blue ledge" and "rotten or brown ledge". Sometimes it looks just like weathered concrete with stones in a cement-like morter, sometimes it's very dark when wet like a chalkboard, and is a blueish color when allowed to dry.

Sump pumps are very common in this area, largely due to lots of wet landscape and as Fred said, water flows on top of ledge. Heat also is conducted very well through ledge, my well line is only 3.5' deep under my driveway (no snow cover) and we routinely see below zero temps for weeks on end. Never any freezing issues, there is 4" of blue board over it, an it's in a 4" PVC pipe sitting directly on blue (hard) ledge.

One great thing about being directly on ledge is that the is absolutely NO ground movement, and I have seen zero cracks in my slab or drywall.

TS

 

[BoilerMan]

Pretty sure radon can go through a "slab" just as easily as it can go through a basement floor.

Yes you are correct. I have heavy (8mil if I remember) poly overlapped 12" and taped. Then 2" T&G blueboard also taped. This is after we removed all of the organic matter from the ledge and filled with bank-run gravel.

TS

 

[velvetfoot]

On a lake where you have fishing boats blasting by and snowmobiles, it can get quite noisy!

I lived in a rental on a lake for a year and found the same thing. They were racing snowmobiles up and down the lake at night. ugh.

 

[Cal Stanley]

Hello, I just stumbled onto this forum last night and have been reading ever since. What a fantastic resource of information.

My wife and I have a 2 acre piece of land in the Matunuck section of South Kingstown, RI that we have cleared and are building a home on. We have just hired an architect.

The land does not have access to town water or natural gas and because of its proximity to the ocean it needs an Advantec septic system.

We would love to stay away from oil or propane except the using propane for the cooktop. We debated Geothermal and it's still an option but the up front costs are very high.

I just found the pellet boiler option this morning when researching fireplace inserts. I had no idea they existed as they are nearly non-existant in Rhode Island.

I have liked what I've read so for but have a few concerns.

Do they need a backup system? Is it truly feasible to all my heating and DHW needs? Is the initial cost prohibitive when compared to oil or propane systems?

Thank you for any and all advice. It is truly appreciated.

My wife and I recently finished our house in Maine - a ranch with 1430 SF of living space.

SIP walls (about R-22) / Closed cell foam and cellulose over the ceiling (R-63) / Basement insulated to R-20 on the inside / Rim joists R-21. Every seam is taped – as close to air tight as I could make it. I installed a heat recovery ventilator (HRV) to take care of air exchange.

Electric stove/oven, dishwasher, electric water heater (heat pump - GE GeoSpring), washer and dryer NOT running yet.

I originally planned to use a Harman P68 pellet stove in the basement as this is what we have been doing for the past 6 years in our old house. With the government offering a 30% rebate on the system, I looked into GeoThermal. System cost from 2 vendors was about $24,000 (before rebates). Based on oil at $3.50 a gallon, payback would be about 6 years compared to oil heat. Based on $200 per ton, between 15 and 20 years compared to a pellet stove.

During the hot spell we had last summer, we decided to install a Fujitsu mini-split for cooling and let it take up some of the heating load in the colder months. These things are incredible. We are getting 100% of our heat from this 12,000 BTU rated mini-split. The wall unit is mounted in the dining room at one end of the house. That end stays at 68° plus with no problem. The far end (bedrooms) run about 3-4° cooler. We haven't used the pellet stove at all.

Our highest electric bill this winter was for the month of January and that was $205.66 and that was $20 more than December. That's our total electric bill including heat.

The outdoor unit is the AOU12RLS2H
indoor ASU12RLS2 (single indoor unit)

(broken link removed to http://www.fujitsugeneral.com/wallmountedRLS2H.htm)

 

[heaterman]

A pat on the back for you Cal. You did your house right.
Make it as air tight as possible, then use mechanical heat recovery ventilation where needed......and that would be any house built like yours..

We are seeing the same results with the Mitsubishi units we've installed. They performed well down to near zero here this winter before efficiency started to fall off. One customer with a house much like yours reported his highest electric bill this winter (still not over here) was $138. Theirs is a 1-1/2T condenser with 2 indoor units. They use a very small indoor wood stove to supplement when the outdoor temp was single digits or below and keep the house at 72* day and night.

 

[AndrewChurchill]

You could look at the Pellergy system. Mine is connected to a Buderus boiler and I have it set up so I can switch over to propane in about 5 minutes. All I have to do is remove two bolts to remove the door and unplug the Pellergy burner. Then I put the propane door with the attached propane burner on, make attach the quick connect and plug the burner in.

Of course it's not an automatic switch over but it saved me several thousand dollars by not having to put in another boiler.

 

[moey]

My wife and I recently finished our house in Maine - a ranch with 1430 SF of living space.

SIP walls (about R-22) / Closed cell foam and cellulose over the ceiling (R-63) / Basement insulated to R-20 on the inside / Rim joists R-21. Every seam is taped – as close to air tight as I could make it. I installed a heat recovery ventilator (HRV) to take care of air exchange.

Electric stove/oven, dishwasher, electric water heater (heat pump - GE GeoSpring), washer and dryer NOT running yet.

I originally planned to use a Harman P68 pellet stove in the basement as this is what we have been doing for the past 6 years in our old house. With the government offering a 30% rebate on the system, I looked into GeoThermal. System cost from 2 vendors was about $24,000 (before rebates). Based on oil at $3.50 a gallon, payback would be about 6 years compared to oil heat. Based on $200 per ton, between 15 and 20 years compared to a pellet stove.

During the hot spell we had last summer, we decided to install a Fujitsu mini-split for cooling and let it take up some of the heating load in the colder months. These things are incredible. We are getting 100% of our heat from this 12,000 BTU rated mini-split. The wall unit is mounted in the dining room at one end of the house. That end stays at 68° plus with no problem. The far end (bedrooms) run about 3-4° cooler. We haven't used the pellet stove at all.

What did you use when it got to -20F or below? At least where I am midcoast maine we had several days when it was -25F. I'm in the process of doing my rim joists to R24 foam and my basement walls to R20 cant wait to see the results.

 

[peakbagger]

The original poster posted from Kingston RI. I expect the winter design temp is probably over zero. Building to an energy efficient standard these days is no brainer, unfortunately many folks would rather spend the extras dollars on for improving efficiency on extra features on the house. If there is a need for a pellet boiler, then the house is designed for style rather than energy efficiency. Several mini splits is the way to go with electric backup and enough solar panels on the roof the net out the house over the course of a year.

In northern NH with far lower design temp and a record cold winter on a 20 year old house, I installed a 1 ton Mitsubishi hyper heat and cut my wood usage by a third and burnt less than 100 gallons of oil since last summer. If I add another smaller minisplit for the second floor I expect I can cut my wood usage down further. I don't have a huge PV system but it looks like I will be able to cover all my electric costs with PV through net metering.

GIven that the typical pellet boiler costs, that money is far better spent on PV and a minisplit.

With regards to Radon, most studies indicates that sealing without negative ventilation doesn't work. Be it a slab or a basement floor, the intent is to maintain a vacuum under the slab above that of the house under the slab so any radon goes out the vent. Sealing the slab or floor reduces the size of the fan but it doesn't eliminate it as a heated house will always be negative relative to the outdoors.

 

[DBoon]

Hi Briarwood,

Welcome to the site!

Like Cal Stanley (also, welcome to you!), I also put in a Fujitsu mini-split heat pump, and had similar and good results. Mine was the 15,000 BTU (rating is for ~5 degrees F, from what I remember, more at higher temperatures). The RLS2H models are the ones to go for - they provide good heat down to -17 degrees F. The Mitsubishi hyper-heat units are also an equivalent alternative, but they were pricier in my area.

If you are a neophyte to construction, you should look into joining the Northeast Sustainable Energy Association (NESEA). They are a fantastic resource and can get you in touch with a lot of top-notch contractors who can consult or build "energy-smart". Get the initial design done right for efficiency, insulation, sealing, etc. before you decide on your heating infrastructure.