Hello,

I'm a first time poster and live in MA.

I've built a 16' x 20' 320 sq. ft. room off the north side of my house. It has lots of Harvy vinyl windows (low-E glass) which encompass most of the wall space. The ceiling is cathedral (R30) with 2 fans, 11' to the peak with 8' high walls (R13). The room is constructed on piers and as such the underneath (R30) is exposed to the cold. The only sun it gets is from the west, which is'nt much. 

We plan on using this room as a family room year round.

I have an old 1952 American Standard oil fired boiler with baseboards.

Question:  What's the best way to heat this room?
                  
                  Baseboard, radiant (electric,hydro). electric baseboard, wood/pellet stove

Thank you in advance for your responses.

Cold in MA.

"Best" can mean different things to people.   Are you looking for most comfortable?  Least costly to install?  Least costly to run?  Most convenient?

As for adding baseboard or radiant onto your existing system... you will need to determine heat load for your entire house to determine if your existing boiler has the "free" capacity necessary to heat this new room and the remainder of your house.  It is likely to be over-sized (because most heating systems are) so it might not be a problem, but you will want to be sure.

Electric baseboard is likely the least expensive to install, but costly to run.

Pellet and wood stoves are likely to be the least expensive to run, but they require the most "user intervention".  Are you okay with lugging wood or pellets through the snow and cleaning out the ashes?

As you can see, there are things you must take into consideration.

On a slightly different note... if your floor is insulated with fiberglass and "open to the air", you are going to want to seal that (I'd suggest a rigid foam board).  Air flow will completely defeat the fiberglass and you will always have a cold floor (and a lot of heat loss).

Regards,
Ed 

Thanx Ed.

Radiant would be most comfortable, but not cheap. (electric radiant would be cheaper to install, but expensive to run, hyrdonic radiant can be costly up front.

Hydronic baseboards running of the same boiler as the rest of the system would be pretty comfortable, not too expensive to install or operate.  It needs to be it's own zone though, as the heat loss characteristics may make it very difficult to balance with a zone over a full basement or slab, especially since this has a HUGE glazing heat loss factor.

If you're cast iron beast of a boiler is in good condition after nigh-on 60 years of service (and many are), it could still be running efficiencies over 80% as long as it's not short-cycling.  Have it's combustion efficiency checked sometime, and measure it's duty-cycle & minimum burns.  If the raw combustion efficiency is under 75% and can't be tuned up higher, it may be time to replace it. If it's over 80% and the minimum burn cycles are over 5 minutes, it's not terrible. If it runs much shorter burns you can probably cut fuel use by double digits using the retrofit economizer controls from Intellicon or Beckett .  (Often a DIY project, for a couple-hundred up front for the hardware the ROI is pretty good.)  Retrofit "outdoor reset" controls are typically a bit more expensive, but may deliver slightly better savings (and aren't as easily DIY installations.)

Small woodstoves etc may make more sense if this is an occasional use room, but it takes more user interaction & maintenance than hydronic baseboards with a programmable thermostat running it.  The heat loss of all that glazing is quite high, so running that zone with a programmable setback will save quite a bit. (Letting it fall to 50-55F overnight while you sleep is fine, and the boiler is probably big enough that it can recover ~15-20F in 60-90 minutes if you give it enough baseboard to work with.  Timed to begin the recovery burn an hour ahead of when you'd usually expect to use it is probably the right thing to do. )

Keep track of your fuel use, read the specs on the side of the boiler, and when the time comes you'll have a good chance of sizing the boiler properly for the load (most I've seen in MA are 3-4x oversized, with high fuel-consumption consequences.)   Play around with the FSA calculator downloadble online here:  


http://www.nora-oilheat.org/site20/index.mv?screen=home

A synopsis of the science behind the model used by the FSA tool lives here:

http://www.nora-oilheat.org/site20/uploads/FullReportBrookhavenEfficiencyTest.pdf

I'm by no means an expert, but I'll give my opinion..  Based on your description (north facing, lots of windows, on piers), you're going to have significant heat loss - I can't imagine that it's a very efficient room (not faulting you, sometimes there's only so much you can do).  If it were me, I'd focus on the lower operating costs since I know I'm going to be losing a lot of the heat I'm producing.  I'm looking into a pellet stove in lieu of a fireplace in our great room.  The more I see, the more I like them.  There is more "upkeep", but even a small stove should have a hopper that holds 50 lbs of pellets.  The smallest stoves I've seen are rated to heat up to 1500 sq ft, so if you're heating 300 it shouldn't be running constantly.  I wouldn't be surprised if you could get a couple days of heating before needing to dump in another bag.

About ash cleanup, I saw some that are direct vent & have a heat exchanger.  In the process, they kind of expel the ash out the vent, so cleanup is very minimal.

Something else to consider, that you didn't mention.  Assuming that you are going to have fairly high heat loss, you may want to consider installing some doors to separate the addition from the rest of the house.  When you go into the room, that pellet stove would heat it up very quickly..

As far as cost, they are not terribly expensive.  The units we were looking at (those smaller ones that heat up to 1500 sq ft) were $2300-$2700, for the most part..

Thanx for the input!

The thing with pellets is I need a place to store the bags.

Don't forget to get your $$ from the Feds when you get a biomass stove.

 

Steve

Thanx Dana for the in depth discussion.

I figured if I insulated well that would be enough.

Maybe this room should only be 3 season?

 

Steve

Steve,

If you make this a 3 season room, (which makes sense to me) be carefull using a seperate zone on your hydronic heating.  IF you don't heat the room and it gets cold enough, the pipes will freeze and burst which is never pretty.  If you go hydonic, you need to heat it in the winter (you could set it to 45° though).

eric

For a simple heat-loss model, insert the insulation parameters here:

http://www.chromalox.com/resource-center/calculators/comfort-heater.aspx

To come up with the R-factor for the windows, look up the U-value from the manufacturer, and insert it into 1/U=R.  For the R-factor of the walls use:

http://www.ornl.gov/sci/roofs+walls/AWT/InteractiveCalculators/NS/Calc.htm

The floor's R-value won't be the R-30 you have stuffed in there, due to thermal bridging of the joists- figure it's really ~R25. Use similar fudge-factors for the ceiling.  For the wall abutting conditioned space, use R100.

For Burlington MA, your design temperature (for sizing the radiation or stove output) would likely be ~3-5F, but use 0F if you like.  If you use 1.5-2x as much radiation or stove as is required for maintaining the heat, recovery from deep setbacks will be quick and you can let temps fall to ~50F when you're not in there to make it cheap to heat.  (Using the room heat loss tool, see how much LESS you lose at 50F than at 68F, even when it's zero out.

To get a crude estimate the fuel use, the average daily temps in Burlington for January/February are ~25F. From that you can calculate the fuel use at 50F, 60F & 70F.  If you have a 50F overnight setback it'll probably average ~60F for those hours, and use 70F for the occupied hours.  Heat loss per hour x hours will be the total BTUs lost.  Assume the boiler & system is running 75% efficiency, so  142000BTUs/gallon in fuel energy becomes ~100,000 BTUs delivered as heat to the room- every 100,000BTUs of heat lost is a gallon of oil burnt.  A setback thermostat and extra baseboard to allow deep setbacks will cut the fuel use by a significant fraction (could be 15% or more on a very lossy room that's only occupied 6-8 hours out of every 24.)  Mind you, the true heat loss during the day will have a lower average- this calc will be imperfect, but should hit within 25%. If you want to calculate for December & March, use 40F for an average outside temp. November & April will be but a fraction of the heat load of January & February, and won't model well with crude arithmetic.

Then you can figure whether you really want to pay the fuel to be able use it from half-past December until half-past March.

Tight fitting insulating shades/shutters can improve the heat loss of the glazing considerably, but requires user-diligence.

You should put glasses in windows for to keep sun light heat in your room.




General Contractor Virginia

In our country people use for heating national brand heater that is the perfect result of heating when if you want to buy heater i advice you national heater is provide you best result.

Load shouldn't be that high for a 320SF room. To qualify as living squares in many places you have to have the ability to maintain 68*.....automatically, ruling out solid fuel.
In the abscence of automatic heat the area becomes "unoccupied" which may have property tax advantage.

If you want to heat it baseboard would seem the way since you already have the heat plant.....depending on electric rates however, 3$ gallon fuel oil can cost more than resistance heat.

Finally console units (like those in a hotel room) are relatively in expensive and offer cooling as well.

j

It probably isnt the cheapest solution named, but what about a small mini split HP or something?  I will probably use a 4 zone hp to heat my entire house, at least that is the current plan do to such a low load. 2 heads up and 2 heads in the basement. 

Supposedly talking with a Mitsubishi rep directly, their mini split compressors only run to the demand required, and ramp up and down to meet the load...differently then even a 2 stage "traditional" HP. 

Posted By lzerarc on 15 Aug 2011 09:48 AM

It probably isnt the cheapest solution named, but what about a small mini split HP or something?  I will probably use a 4 zone hp to heat my entire house, at least that is the current plan do to such a low load. 2 heads up and 2 heads in the basement. 

Supposedly talking with a Mitsubishi rep directly, their mini split compressors only run to the demand required, and ramp up and down to meet the load...differently then even a 2 stage "traditional" HP. 

Mini splits have come a long way offering true variable compressors. Where duct work isn't required however (1 room addition) folks would probably be better off with a geo console unit as it would qualify for a tax credit.
j

You all realize that the original post was from 1.5 years ago...

Doing geo (or even a mini-split) for just one room would be ridiculously expensive compared to adding some baseboard to the existing system, but it would be worth getting quotes for both a mini-split and adding baseboard. (What does even a half-ton geo console system cost, starting from scratch?)

A 3/4 to 1-ton mini-split would run ~$3.5-4K, and even at the relatively high local electricity pricing it would be quite a bit cheaper to operate than oil. Better 1-2 ton mini-splits will run a heating season average COP of ~2.5 in this climate (and also qualify for tax credits, albeit not as generous as for geo.) Even at 18-22cents/kwh it still beats $3 oil in an old-school boiler on operating cost, and at $4 oil it's a slam-dunk. (At current oil pricing I've come around to advocating retrofitting mini & multi-splits into homes with oil heat, using the oil-burner as the hail-mary design-day backup. The economics can be compelling.)

Posted By Dana1 on 17 Aug 2011 04:24 PM
A 3/4 to 1-ton mini-split would run ~$3.5-4K,...

That pricing seems pretty high.  You can buy off-brand mini-split heat pumps in that size for <$1000 online. 

You can get Fujitsu and Mistubishi 9000-12000 BTU 23+ SEER single zone heat pumps online for <$1800.

folks would probably be better off with a geo console unit

How is that figured? It's hard to believe you could be better off with a geo unit and all the associated loop and pumping when you need a single room solution.

Posted By ICFHybrid on 18 Aug 2011 01:31 AM

folks would probably be better off with a geo console unit

How is that figured? It's hard to believe you could be better off with a geo unit and all the associated loop and pumping when you need a single room solution.

Posted by Dana

"Doing geo (or even a mini-split) for just one room would be ridiculously expensive compared to adding some baseboard to the existing system, but it would be worth getting quotes for both a mini-split and adding baseboard. (What does even a half-ton geo console system cost, starting from scratch?)"

Reply by Joe:
Agreed, I didn't suggest geo except in comparison to a variable speed mini-split. Baseboards make sense or the original console suggestion I had (non-geo).
A geo console may cost about the same as a variable speed minisplit (not talkin thousand dollar mr slim here) with loop perhaps $1,000. With tax credit (30%) it could easily be the cheaper of the 2 bad choices. might be cheaper outright with open loop and a place to drain.

Posted by Joe 15AUG
"If you want to heat it baseboard would seem the way since you already have the heat plant.....depending on electric rates however, 3$ gallon fuel oil can cost more than resistance heat.

Finally console units (like those in a hotel room) are relatively in expensive and offer cooling as well."

This post (15Aug) adds context to my follow up comments........that's how I figured.
j

Thanx to all who are and have responded to my ?

Please continue conversation as I am gaining knowledge as we go!

Since my original post I have insulated room w/ r13 walls, r34 dense pack and sealed the best I could with foam (no venting), and since it's on pillars I put up r30 batts w/ tuff r 2 sided foil faced board r10 taped seams and foamed all edges.

Thanx again to all!!!!!!!

Steve

I should add there is a lot of glass 2 pane low e argon
(3) 5 x 8 and (2) 5x9 ft and a 6 ft slider
I don't know if the slider has gas but is 2 pane
All are vinyl. The rm is 16x20 w/cathedral ceiling.

Thanx