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radiant and or furnace heat in basement question

noah99 Member Posts: 10
Hi all,
I have a 2500sq ft. basement with radiant zoned floor heat by a viessmann boiler as well as a Trane xc95m furnace supplying heat to the area. We have lived in the home for 4 years and in the past I have closed off all the heat registers and just ran the floor heat in the basement and use the furnace for the rest of the home. This fall I have been reading that I should never close my heat registers in the basement in the winter and have since opened them(I have no dampers installed to decrease the basement flow). The temperature is now very comfortable in the basement at 21-22c, but I have not even turned on the floor heat yet(live in Canada). My question is how should I set up the heating my basement with radiant or furnace heat or a combination? and which is most efficient. My basement has been very comfortable in the past with the radiant heat and would like to continue this way but I am concerned about having all the basement heat registers closed and causing issues with my furnace as well as no fresh air being introduced into the basement living space. Any help with this would be greatly appreciated as I am sure there are other homes that have this type of set up and would like to know how they heat their basement.


  • Tim McElwain
    Tim McElwain Member Posts: 4,593
    Go ahead and close those registers to almost closed just so a little air movement will be available and go back to using the radiant. That should work fine.

    The article probably did not want registers closed for fear that pipes would freeze, that will be more than taken care of with the radiant.
  • Gordy
    Gordy Member Posts: 9,537
    Do you have returns in the basement, and in each room except kitchen , and baths upstairs?

    That furnace modulates, and has a variable speed blower. As Tim said you should be fine.
  • noah99
    noah99 Member Posts: 10
    yes there are cold air returns in all the rooms in the basement and in the other rooms in the home other than the kitchen area and bathrooms. will leaving the registers open just a bit prevent any chance of a neg/pos air pressure issue in the home
  • Gordy
    Gordy Member Posts: 9,537
    You will be fine.
  • don_9
    don_9 Member Posts: 395
    I would not closed the register bc what would happen is the fan will ramp up to try and maintain airflow.more power comsumption not to mention higher temp rise across the hx causing the furnace to cycle on limit.what you could do is install a zone damper system with a bypass n connect the basement zone on a two stage heat tstat,let the infloor be your primary heat n the furnace second stage.You can even add a outdoor stat along with it to hold the basement zone out even longer.Just for the record, a psc motor would last longer then a ecm motor when it facing a high static distribution system.Closing your vent will create a higher static issue which means a very short life for that very expensive ecm motor.
  • noah99
    noah99 Member Posts: 10
    I have 34 heat registers in the home and have read that it is acceptable to close 30% of them with out problem? I may only leave a few open in the basement(11 registers) just a bit to help airflow and not really heat so my floor heat would be the primary heat source would this be ok
  • Gordy
    Gordy Member Posts: 9,537
    Like suggested just leave them open a wee bit. WAtch furnace for cycling
  • SWEI
    SWEI Member Posts: 7,356
    How many you can close without impact depends on quite a few variables (duct sizing and design, the particular motor and fan characteristics, air density, and more.) A variable-speed constant-pressure ECM is the real answer.