Results 1 to 7 of 7
  1. #1

    Three floors with one zone thermostat help please.

    Hello.
    I live in A cold part of UT. This is the first house with a basement that I have owned and also the first time that I have lived in a cold climate.

    I will ask my question first with the backround info below.

    I have three levels with one zone/thermostat. Is there a way to add remote programmable temperature sensors that ONLY turn on the recirculation fan for the HVAC to even up the temperature of the house when the temperatures vary from the main t-stat by X number of degrees?
    OR
    Are the thermostates with the "recirculation" feature where they turn on the FAN for so many minutes 4 or so times a hour effective enough to use that instead of investing the extra money with remote sensors?


    The basement is partialy finished (to be fully finished at a later date), this is also where the gas furnace and central AC is located.

    The house has a total of 3300 SQ FT with aproximately 2500 finished. There are three floors including the basement.

    There is only one HVAC unit unfortunately.

    My issue is that it is difficult to attain an even temperature throughout the house. I have modified the cold air return system to make the basement bearable in the winter. It was totally unusable before. To do this I isolated the utility room in the basement where the HVAC unit is from the rest of the unfinished portion of the basement(drywalled the triangle shaped wall below the stairs). I also added a cold air return with a filter from the finished portion (basement living room) since I found that the suction of the fan has a 3"x 20" opening (that pulls air from the utility room) along with the regular cold air ducting that pulls from the base of the stairs on the main level and another one on the stairs to the basement. I also (after testing the effects) blocked about 60% of the cold air return that is located on the basement stairs (near the top). It now seems to draw more warm air into the basement living room and it is MUCH more comfortable, yet still 3 or 4 degrees cooler than the main level.

    If we plan on using the basement in the winter OR if I am working nights we turn the Fan from "AUTO" to "ON" to even out the temperature for the basement to be comfortable (warmer) or the Master Bedroom (top floor) to cool down if I am sleeping durring the day (southern exposure).

    Thank you for your time.

  2. #2
    Join Date
    Jun 2002
    Location
    Dacula, GA
    Posts
    12,549
    You can do it by eliminating return air ducts. Just put open grills in the top and middle floors so you have free air return all the way to the basement. Then modulate your supply ducts from each floor for heating and cooling. Heat rises and cool air falls. Have your air flow wide open for the basement in the winter and choke it down some on the 1st floor and a lot more on the top.

    For the summer let your return air cool your basement and modify your 1st floor and have the ducts wide open on the top and no supply air for the basement. That should help a lot. I have modified homes where they wanted the basement conditioned this way and by taking the return ducts in the basement (if they have any) and turn them into supply ducts for the basement operating in the winter and or shut off or severely choked in the summer. This works great for me and that what I have set up in my 2 story with a basement.
    "I could have ended the war in a month. I could have made North Vietnam look like a mud puddle."
    "I have little interest in streamlining government or in making it more efficient, for I mean to reduce its size. I do not undertake to promote welfare, for I propose to extend freedom. My aim is not to pass laws, but to repeal them. It is not to inaugurate new programs, but to cancel old ones that do violence to the Constitution."
    Barry Goldwater

  3. #3
    I do open and close registers to move air around for the different times a year. Right now the top floor is relatively closed, mid floor are somewhat open and the basement room is wide open. I basically reverse it for the summer. Each room is modulated to the need (for instance my daughter's room needs more warm air in the winter with two exterior walls, one east facing and one north facing, as compared to my bedroom which has one exterior south facing wall and tends to be much warmer than hers.

    When the system is on and actively conditioning the temperature everything is good, it is when the system is off and the cool air settles to the basement and the warm air rises there is the issue. Since the T-stat is on the main floor the temperature is still comfortable and the T-stat is still satisfied and does not necessarily turn on the heat or AC.

    I am looking for something to even up the temp (turn on the fan) when the system is not actively conditioning the air without having the fan blow 24/7/365. Something more intermitten. That is why I am looking at using the t-stat to regulate the temp. Eventually, I may have to add astand alone heater for the basement once the bedrooms are added.

  4. #4
    Join Date
    Jun 2002
    Location
    Dacula, GA
    Posts
    12,549
    You can use thermal diffusers with built in thermostats or wall mounter thermostats. The build in ones cost around a hundred or two or more and will adjust the air flow to suit your needs in your room which in effect is a zone control for your room or just add on a few zone dampers with thermostats for certain areas and that is down and dirty but you would always have to have some "open" areas to keep the flow across the coil or furnace. Nothing easy here to improve on your existing set up.
    "I could have ended the war in a month. I could have made North Vietnam look like a mud puddle."
    "I have little interest in streamlining government or in making it more efficient, for I mean to reduce its size. I do not undertake to promote welfare, for I propose to extend freedom. My aim is not to pass laws, but to repeal them. It is not to inaugurate new programs, but to cancel old ones that do violence to the Constitution."
    Barry Goldwater

  5. #5
    Join Date
    Jan 2009
    Location
    Keokuk, IA
    Posts
    5,520
    That's a good point, you can isntall independant zone dampers with it own thermostat. THe difference is that only a central zone controller can initiate a call for heating or cooling. Thsi "poor mans zone" system uses the main thermostat as a master temp controller and just modulates airflwo to the other zones locally. It only works to reduce flow to spaces that are overconditioned, but that in itself can help divert flow simultanously to areas underconditioned. Teh dampers don't have to close 100%. You can set a minimum position.

  6. #6
    Join Date
    Dec 2011
    Location
    Fort Worth, TX
    Posts
    80
    This is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise, commentary, or ask questions of the OP here.

    You can find the rules for posting and qualifications here.

    Further infractions may result in loss of posting privileges.
    Last edited by beenthere; 02-28-2013 at 04:22 PM. Reason: Non Pro * Member

  7. #7
    Join Date
    Dec 2011
    Location
    Twin Cities Minnesota
    Posts
    237
    Get one of those Infra red temp. guns,check temps of basement walls,and above on "sill plate"if not insulated can effect alot! I had 43degress at ground line on cement block, at sub-zero temps!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event