My basement is almost completely finished except for a 180 sqft room. This room is right next to a utility space containing a high efficiency Lennox furnace. This photo is looking into the utility space from the room I plan to finish:

Utility room with furnace

I'm planning to remodel/finish the room to be used as a home office and close off the furnace space, but I need a way to heat the room (cold long winters here in MT).

I thought about underfloor electric radiant heat, but it's expensive and not nearly as efficient as my furnace.

Given that the furnace is so close and accessible, is it possible to add a separate zone off the furnace to a single vent near the flow? Or any better ideas?

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    you can basically knock a hole in that big round pipe on the left for now, hook it to a vent when finished. if you want a zone you'll need one of those electric damper things. – dandavis Feb 16 '18 at 20:28

Yes, assuming your furnace is adequately sized to also heat this additional space, it should be fairly easy to add ductwork that serves it. Controlling it as an independent zone may be more complicated: because it's a small room, if it's calling for heat when the rest of your home is not, your system might be significantly overpowered for that zone. That would mean too much heat and too much airflow trying to go to a smaller space. There are solutions for this (multi-stage furnaces, bypass dampers, etc.) but they add cost and complexity.

To judge the capacity, calculate the heat load for your home and for this potential added room. Ideally, you can work out the details of how much airflow you'll need to this room and what size ducting would deliver that. You will get more airflow here because you're so close to the blower.

If the system is powerful enough, you can add supply and return ventilation to serve this room to an existing zone. You can use a manual damper on the supply vent to shut off this area if you're not planning to use it for a while. The downside here is that if the room is cold and you want it warmed up, you'll have to warm up the rest of your house too.

Other options to consider:

  • Electric heating. Expensive to operate, but cheap to install, heats up fast, and provides great room-level control. Electric baseboard is the standard option but you can also do an electric heater with a blower or even under-floor electric heat.
  • Electric heat/cool systems. If you're likely to want cooling in this room in summers, mini-split systems are available that can heat (air source heat pump) and cool. That might not be a great option for you because air source heat pumps don't work well in very cold outdoor temperatures.
  • No built-in heating. You can heat a small room fairly effectively with a plug-in electric heater when you need it. You'll likely get a lot of residual heat from the furnace nearby. Maybe once the room is insulated you will be content with a $20 plug-in heater and a warm sweater?
  • Single-room heaters using other fuels. You can get wall-mounted gas heaters, maybe even kerosene or wood pellets. You can get a wood stove.

Lots of options. The key question may be how you use it. If you're using it frequently, adding the room to an existing heating zone is probably best. If you're using it rarely, electric baseboard is a solid overall option.

  • Great info, thanks! I use the room very frequently as I work from home. At least 8 hours per day on weekdays + a few hours per day on the weekends. Good point about waiting to see what it feels like once insulated. The biggest problem might be the floor currently: concrete is very cold. Planning to do engineered hardwood. – Trevor Hartman Feb 16 '18 at 21:10
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    Make sure you insulate the floor then. Foam boards work well for this. – Shimon Rura Feb 16 '18 at 23:19

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