Full Renovation - Installing new oil fired boiler and indirect water heater

LadyEKent

Hi All I'm new here,

So here is my deal,

We completely gutted a home and are renovating everything. It will be getting all new Anderson 400 series windows, all new spray foam insulation, will have 2 wood stoves, and we will be using flat panel wall radiators, the home is roughly 2500 sq ft.
I am doing my darnedest to keep from oversizing the boiler too much, yet every company I speak to wants me to put 100-120k btu worth of boiler into the house which I feel is excessive.

I don't intend on putting more than 45k worth of radiators into the house, I see no need for it. I told the most recent heating company that I would like to install the smallest of the Burnham MPO IQ series oil boilers, but they still came back saying that I need at least 100k of BTU. With the 45k worth of radiators and the indirect water heater (stainless, likely 40-50 gal, I think they suggested Super Stor), do i really need more than the MPO IQ 84? Or am I screwing myself with too little radiation? I appreciate any advice on this matter.

LadyEKent

Yeah Ive been researching for over a month at this point and from what I can tell, you are right in me needing less than the IQ 84. I guess my real concern is if I need to add more radiation to keep up with that boiler or if it will be fine with just the 45k worth of radiations and indirect water heater.

LadyEKent

For heatloss, is there an easy way to do a calculation? The home is in the Manchester NH USA area

SWEI

It all starts with a room-by-room heat loss. From that comes radiator sizing, pipe sizing, and boiler/controls decisions.

If you are not planning on using TRVs, I would suggest putting the room(s) with the woodstoves on a separate zone (or zones.)

There are a few smaller (70k) oil-fired boilers available from other makers. What are your oil and LPG prices like there?

GreenGene

If you're half decent with a computer you can use this, go to the info tab and pick the options that best match the house and temperatures, then go to the input and put in each room, all the windows and exterior doors for each room and eventually below your cool and heat load numbers will add up.

You'll probably end in the 65-80k range.

LadyEKent

GreenGene said:

If you're half decent with a computer you can use this, go to the info tab and pick the options that best match the house and temperatures, then go to the input and put in each room, all the windows and exterior doors for each room and eventually below your cool and heat load numbers will add up.

You'll probably end in the 65-80k range.

when calculating the floor area/floor edge in this program, what exactly is the difference between the two

NEVERMIND

LadyEKent

SWEI said:

It all starts with a room-by-room heat loss. From that comes radiator sizing, pipe sizing, and boiler/controls decisions.

If you are not planning on using TRVs, I would suggest putting the room(s) with the woodstoves on a separate zone (or zones.)

There are a few smaller (70k) oil-fired boilers available from other makers. What are your oil and LPG prices like there?

I hadnt considered putting the room with wood stoves on a seperate zone, seeing as they are both on the first floor and with a mostly open floor plan (basically one large room with a bathroom and office), the first floor will have its own zone.

Oil is 1.98 and Proprane is 2.52

SWEI

The idea is to shut off the heat to rooms as they are heated by the wood stove. If the heat makes its way into other rooms, the thermostat for those areas will shut down the boiler. TRVs will give you even finer-grained control over the system.

At that price, keep the oil.

LadyEKent

So basically if I can convince the husband to insulate the floor of the 1st floor/ceiling of basement, the btu heat loss will be less than 58k

JUGHNE

A concern I see is where does the make up air for the 2 wood stoves come from. With a house you hope will be as tight as you are paying for, there is not a lot of air infiltration for combustion air for the stoves that will move a lot of air up their chimneys.

I know of a house spray foamed in the 70's that cannot use the fireplace (I know it is a big air mover...more so than a stove) and run the clothes dryer at the same time. Smoke down the chimney.

You have to consider that a clothes dryer, bath and kitchen exhaust fans require a lot of air coming into the house. Sometimes it finds that air by pulling in down your chimneys.

That 70's house always had oil burner sooting problems until a combustion air pipe was brought directly into the furnace cabinet from the well ventilated attic space.

Your basement if unfinished may have enough combustion air for an oil burner boiler.......but 2 wood stoves upstairs.....it may be too tight. IMO

SWEI

Combustion air is a big deal. A barometric damper can work wonders for a woodstove.

JUGHNE

That damper could be for the basement/boiler space and if the basement area is fairly sealed from the upstairs wood stoves, they may not benefit from it.
I have cut in a fairly large floor grill behind wood stoves to get air from the unfinished basement or crawl space.

Some wood burners have combustion air provisions included....always a good idea. IMO

SWEI

I was thinking along the lines of a Field Controls MAS.

JUGHNE

Is there ductwork in the house?

Harvey Ramer

You can go smaller with a Burnham LE series oil. They can also be down fired, with the proper baffles of course. They are high efficiency, as oil boilers go. They do need protection against condensation and the are more noisy than the mpo. They are a sweet little boiler though.


Just make sure you have a spin on oil filter installed on a small boiler like that. It will save you a ton of grief.

kcopp

I would look into QHT products. They have both 3 pass oil boilers and panel rads. The N. American stocking dealer in out of portsmouth and Bell Simons on Holt Ave in Manchester stocks them.
I am in the Seacoast so its a bit out of my way...