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Would like to add second furnace?


C-COOP's Avatar
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04-03-18, 07:50 AM   #1  
Would like to add second furnace?

I have a mother-in-law suite that is connected to our utility room in out basement. It is always cold in there and would like to add it's own thermostat and heating source. (no interest in trying to balance the existing heat in there) I know electric heat is expensive so was thinking a small furnace or a gas fireplace. Unit can be in the suite or could be in the utility room next door and just blow into the suite. Any thoughts/advice for you all?

Maybe considering something like this:
https://www.homedepot.ca/en/home/p.d...001058676.html

 
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Tony P.'s Avatar
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04-03-18, 09:33 AM   #2  
I can't comment on your specific question but I'd like to offer two related thoughts. First, consider the option of baseboard heat, particularly if the space is not used on a full time basis. While electric heat may be less efficient to operate, the initial cost savings may make that option worthwhile.

Second, if the space isn't well insulated, doing so may increase your comfort substantially.

 
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04-03-18, 10:07 AM   #3  
Electric heat may not be cost effective heat but it is 100% efficient.
Every dollar of power you put into the heater comes out as heat. No flue - no loss.

A direct vent gas heater is a good choice but must be directly vented thru an outside wall. Could be tough in a basement if it's below ground.


~ Pete ~

 
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04-03-18, 10:10 AM   #4  
Adding or modifying heat should always start by answering the question of "how much"?
Part of that question involves, "what is there now".

One reason this approach is important is because cold walls will remain cold even if you improve the air temp. People inside will be subject to sharing their body temp with those cold walls and thus the level of comfort improvement may not be significant.

on the other hand, if the walls have very little insulation and the rim above has not been air sealed, the decision may be a lot easier if those are done first.

I installed an 8,000 btu gas heater into a small room for my father and it really didn't do the job, that was before I got into energy efficiency. Now I know why.

Bud

 
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04-03-18, 12:35 PM   #5  
It is a completely insulated space and currently has vents from the house furnace in it. It just is the coldest spot in the house. Would like to have a thermostat in the suite that can top off the heat to warmer than the rest of the house.

Maybe I should revisit electric heat, but costs so much more to run though.... really think it should be gas.

 
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04-03-18, 01:09 PM   #6  
The cost to heat it with electric is directly related to the heat loss. If it is well insulated the electric cost will be minimal. Until you do the heat loss calculation you don't know how much heat to add or how much it might cost.

If that cost was going to be $10 per month in the winter you would go electric in a heartbeat. If it was projected to be $400 a month you might revisit how well it is insulated. In between those two numbers would still have the information to make a value based decision. There are people here who can help you do that heat loss determination.

Bud

 
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04-04-18, 07:19 AM   #7  
It is well insulated, including subfloor - but it is around 800 sq ft and I think to boost it from 66 to 72 for example would take a heater running almost all the time during the cold months. 750 watt heater is around $125 month running constantly.... Anything gas has to be cheaper....

 
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04-04-18, 08:08 AM   #8  
I could even hang a garage furnace in the utility room and just duct it into the suite. Opinion?

 
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04-04-18, 08:22 AM   #9  
It wouldn’t run any more then needed if it were sized correctly for the load.
A garage heater? You mean a hanging unit heater? Modifying that with duct is a big no no.

 
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04-04-18, 09:52 AM   #10  
I like gas fireplaces for additional heat. They look nice and heat well. But as Pete mentioned, most require outside venting.

I wouldn't discount electric heat. Once you look into gas piping, venting, ducting, etc, you're in the thousands of $$ for a gas furnace or heater. You could get a couple electric baseboards installed for under $1K (much less if you do it yourself). And for a small area, the yearly cost won't be much of an impact.


Good luck... what's the worst that can happen?

 
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04-06-18, 08:14 AM   #11  
Ha - ok, thanks for the replies - I will revisit electric. Maybe the cost won't be too high just to bump up an area a few extra degrees.

 
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04-06-18, 09:57 AM   #12  
Maybe I missed it, but essentially said it "It is well insulated, including subfloor - but it is around 800 sq ft and I think to boost it from 66 to 72". If the existing heat supplied to that space will still be there then you are ONLY looking to make up the additional boost needed. For that some electric baseboard would not be working very hard. I also have seen the wood cabinet heaters that are very safe and could provide that boost.

Your heating needs are not your heat loss but only the difference between what is currently being supplied and what you need.

Bud


Last edited by Bud9051; 04-06-18 at 09:57 AM. Reason: spelling
 
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04-06-18, 12:45 PM   #13  
I willl add to the pro electric baseboard camp.
The lack of noise, safety and ease of installation make this type of heater the best choice for your application.
Any savings gas might have would be minimal.

I would suggest an electronic thermostat, either built in or wall mounted.
It will vary the output of the heater according to the heating load and give very constant room temperature.


GregH.........HVAC/R Tech

 
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04-06-18, 01:08 PM   #14  
Why not a ductless mini split? Or even a ducted mini split? save you tons of money on electric. no gas!

 
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04-06-18, 07:36 PM   #15  
Thinking about this one:
https://www.costco.ca/Dimplex-PLX-Se...100398903.html

Use it with an external thermostat a few feet away....

 
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04-07-18, 05:24 AM   #16  
750 watts is likely not enough heat.
I would take a guess that at least double that would heat the space before cycling off or modulating if using an electronic thermostat.
There also is the requirement to wire a separate wall mounted thermostat, normally on an opposite or adjacent wall.
A baseboard style heater works fairly well when using a built in thermostat .


GregH.........HVAC/R Tech

 
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