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Kenai Keeper
Heating Quandry in Alaska

I finished our basement last year and thought that my idea of in-wall unit heaters would be sufficient due to my walls being ICF floor to ceiling but I was wrong. Two of the three heaters crapped out on me and now I'm approaching a new winter with reservations regarding my judgment on heating choices. I have several rooms and a full kitchen; one room (under the garage) is just storage but gets quite frigid even with it's own door. Our temps here in Alaska drop to pretty cold during the winter, thus the panic of getting a new and efficient heating system.

I have two available loops on the existing HWBB furnace but I can't shake the feeling that there is a more cost effective way of heating the very insulated walls. Can I get some ideas/feedback? Thanks in advance.

NashuaTech
Re: Heating Quandry in Alaska

Kanal Keeper:

There's usually no need to get a different heating system---but some calculations will have to be done to make sure you have enough boiler output and enough convector output (baseboard, rads, in-wall unit heaters, etc.) to provide sufficient heat to the rooms---some insulation may have to be added to non-ICF walls/floors, especially to the sub-floor of the room over the garage---urethane foam is often added to these sub-floors, sometimes with a dedicated radiant copper or PEX loop inside the foam.

Are the heaters that "crapped out" hooked up & a part of the hot water heating system??

Could you post back to advise the OUTPUT of your boiler---this is usually on a name plate at the front of the boiler, and will say something like "70,000 btu/hour output"---also the approx. age of the boiler.

Also post if you can find the heat output. brand & model # of the other in-wall unit heaters and length in feet of the baseboard in each room, and the square footage of each room.

If your boiler operates at 180 degrees water temp (normal) during the winter heating season, then each foot of baseboard puts out approx. 550 btu/hour---it is usually customary in very cold climates to install baseboard around every exterior wall in the room to get sufficient heat output---especially if there are numerous windows in the room, or if the windows are at all drafty, or single pane, etc.

This info can be used to do a HEAT LOSS CALCULATION for each room to establish if you have sufficient convectors in each room--and also if you have sufficient convectors for the entire house---as long as the boiler has sufficient output to heat the house--additional convectors and loops can always be added to get the rooms warmer.

Consult the HLC's below to get an approximation of how much heat in btu's per hour each room needs---then calculate how many feet of baseboard or other convector you have in the room---the figures should closely match.

Adding up the totals of all HLC's for each room should give you the total HLC for the entire house---this figure should closely approximate the OUTPUT in btu's/hour of your boiler.

It should be noted that the HLC's below are only rough estimates---they do not take into account severe drops in temperature, high ceilings over 8', a lot of glass (many windows per room, sliding glass doors, etc.), prevailing winter winds & window/siding integrity, etc.---a comprehensive computer-driven HLC, called a Manual J calculation can be purchased at various rates at various on-line vendors if the need arises.

What part of Alaska is this & how cold does it get???

What is the brand/type of "in-wall heaters you mention??

Please post back.

http://www.bgmsupply.com/calculateheatloss.asp
http://hearth.com/calc/roomcalc.html
http://www.heatload.com

Kenai Keeper
Re: Heating Quandry in Alaska

Thanks for the reply;

the model is a Weil Mclain CGs - 6 pin
DOE Heating Capacity 140,000 BTU/Hr

The square footage in the basement is about 1,250 with just a few windows; the room that is beneath the garage is a variable that I'm undecided as of yet, (weather or not to heat it).

As for the locale? Wasilla, just north of Anchorage about 45 minutes. Coldest temps reach to around -20 for a stretch mid winter in Jan/Feb.

Kenai Keeper
Re: Heating Quandry in Alaska
NashuaTech wrote:

Kanal Keeper:

There's usually no need to get a different heating system---but some calculations will have to be done to make sure you have enough boiler output and enough convector (baseboard, rads, in-wall unit heaters, etc.) to provide sufficient heat to the rooms---some insulation may have to be added to non-ICF walls, especially the room over the garage.

Are the heaters that "crapped out" hooked up & a part of the hot water heating system??

Could you post back to advise the OUTPUT of your boiler---this is usually on a name plate at the front of the boiler, and will say something like "70,000 btu/hour output"---also the approx. age of the boiler.

Also post if you can find the heat output. brand & model # of the other in-wall unit heaters and length in feet of the baseboard in each room.

If your boiler operates at 180 degrees water temp (normal) during the winter heating season, then each foot of baseboard puts out approx. 550 btu/hour.

This info can be used to do a HEAT LOSS CALCULATION for each room to establish if you have sufficient convectors in each room--and also if you have sufficient convectors for the entire house---as long as the boiler has sufficient output to heat the house--additional convectors and loops can always be added to get the rooms warmer.

Consult the HLC's below to get an approximation of how much heat in btu's per hour each room needs---then calculate how many feet of baseboard or other convector you have in the room---the figures should closely match.

Adding up the totals of all HLC's for each room should give you the total HLC for the entire house---this figure should closely approximate the OUTPUT in btu's/hour of your boiler.

It should be noted that the HLC's below are only rough estimates---they do not take into account severe drops in temperature, high ceilings over 8', a lot of glass (many windows, sliding doors, etc.)---a comprehensive computer-driven HLC, called a Manual J calculation can be purchased at various rates at various on-line vendors. I'll look into that but I'm sure that it's all pretty basic, I don't have ANY ceilings in the basement over 8' and the windows are standard sliders (55").

What part of Alaska is this & how cold does it get??? Wasilla, just north of Anchorage

What is the brand/type of "in-wall heaters you mention?? Generic Home-Depot types with on-panel thermostats. (not my best idea)

Please post back.

http://www.bgmsupply.com/calculateheatloss.asp
http://hearth.com/calc/roomcalc.html
http://www.burnham.com/heatloss1.htm

I'm sorry about the confusing post reply's, I have three young daughters that keep pulling me away from the computer... gotta love em! :o

JLMCDANIEL
Re: Heating Quandry in Alaska

One thing you might want to check out is the EdenPure heater. Safe around children and power usage low enough to run off emergency generator.
Jack

BraytonAK
Re: Heating Quandry in Alaska

Kenai Keeper: I'm in Anchorage, so I know what weather you're up against. It's good that you have the CGs for the direct-vent ability. That keeps cold air from being drawn in to make up for the heat that's blown out the flue.

Without knowing the specs of your entire home, I have to suspect that the HWBB could be extended to the rooms of the basement. Adding another zone would be the wisest way to do it, otherwise you'd have no control over the temperature in the basement.

If you are concerned about adding a new zone to your boiler hitting your gas bill, you could have an Outdoor Reset Module installed. This is a vague name for a device that lowers the boiler water temperature based on the outdoor temperature. This can make you feel that your boiler is 'sluggish' to heat, but it does a great job at reducing the amount of gas you consume. With the reset control in place, it works best to just leave the thermostat at a constant setting. The boiler can handle this. If you turn up the thermostat it can take a long time to get to where you want it because the water isn't 180° until your "design day", which for us is -20°F. Set it and forget it. An outdoor reset on the CGs could safely go as low as 140° water temp without risking condensation in the boiler (which would rust it out since it's not made to be a condensing boiler).

Have a heat loss calculation done that factors in the entire living area, but not the basement. I would exclude the basement because it sounds like it wasn't considered as living space when the boiler was installed. If the boiler (140K BTU) is more than necessary for your original living space, then it would have capacity to have a zone added for the basement.

My old boiler was 140K BTU, which was twice the output needed for my home. We downsized to a 70K BTU unit with the outdoor reset. My neighbor on the other side of our zero lot line still has the original boiler setup. Last winter their gas bill peaked at $380, whereas mine was $180. This summer his gas bill is $80 while mine dipped to $19 last month. (That's with a gas clothes dryer and hot water heater.) I'm not sure how much of that difference is just the outdoor reset and just the downsized boiler. I could deactivate it for a winter and let you know! (Yeah, right!) :D

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