SteveC
May 14, 2009, 06:09 PM
Just a litte information that might help somebody.
I'm one of those people that have an extreme sensitivity to temperature changes. Thats why I have so many temp sensing devices in my house.
We just moved into a new home about 60 days ago and I have had and extremely difficult time getting the temperature stabilized to suit me.
So, I have temp sensors in about every room of the house, not all but most.
All of the electronic temp sensing devices have some degree of error in them and it was driving me batty as to why I couldn't get the place stabilized. I like to keep the temp at exactly 70 degrees in the entire house except at night in the bedroom, we like to keep it at exactly 67 degrees, no higher, no lower.
I have an RCS TX15B for main HVAC control and it was reading the temp as I wanted it, but the house was too cool but the bedroom would get too hot when the setpoint automatically rolls back to 67 at 10:00pm.
After researching a bit I came up with the answer. The RCS sets right at the top of the stairs coming from the basement where I have my office with 9 computers generating heat and a family room. Since heat rises it was coming up the stairwell and making the RCS think it was warmer in the great room than it really was, by 2 degrees on average.
So, I hung a standard mercury thermometer in the middle of ceiling in the great room and let it set for 2 hours. I then calibrated the RCS to match THAT temperature rather than what it was reading at the top of the stairs.
Now the RCS actually is reacting to the ambient air temp in the great room instead of the air movement from downstairs and now keeps the greatroom exactly where I want it.
Next problem, we close the bedroom door at night and even with 1 of the two heat vents closed completely and the 2nd 1/2 closed it was still getting too hot to sleep comfortably, SO. I again hung my mercury thermo from the ceiling right in the center of room to get the ambient air temp.
I then installed a Templinc in the bedroom and checked the descrepancy between the two which was 4 degrees. In my 24x7 monitor program I check (every 15 minutes at night) the reading from the templinc, apply the 4 degree offset to get the actual ambient air. If the templinc rises above the desired 67 degrees the program sends a command to the RCS to lower the setpoint by
1 degree which results in a drop of course in the greatroom but keeps the bedroom correct.
We get up at 5:00am so at 4:30am the program moves the setpoint on the RCS back up to 70. At 5:30 HCA does the morning alarm sequence by sounding an X10 chime at 5:00am, 5:15am and again at 5:30am (built in snooze) but, when we get up the temp has risen back to the desired 70 degrees and since the bedroom door is now open the whole house stabilizes pretty quickly to the desired 70 degrees.
We both leave the house at 7:00am so at 6:45 the program sends a setpoint of
65 degrees to the RCS where the house remains until 4:00pm at which time it sets back to 70 and when I get home at 4:30 the house is right where I want it to be.
Just thought you all might be insterested in a 'poor mans' zoned HVAC system. The key was getting the ambient air temp
I'm one of those people that have an extreme sensitivity to temperature changes. Thats why I have so many temp sensing devices in my house.
We just moved into a new home about 60 days ago and I have had and extremely difficult time getting the temperature stabilized to suit me.
So, I have temp sensors in about every room of the house, not all but most.
All of the electronic temp sensing devices have some degree of error in them and it was driving me batty as to why I couldn't get the place stabilized. I like to keep the temp at exactly 70 degrees in the entire house except at night in the bedroom, we like to keep it at exactly 67 degrees, no higher, no lower.
I have an RCS TX15B for main HVAC control and it was reading the temp as I wanted it, but the house was too cool but the bedroom would get too hot when the setpoint automatically rolls back to 67 at 10:00pm.
After researching a bit I came up with the answer. The RCS sets right at the top of the stairs coming from the basement where I have my office with 9 computers generating heat and a family room. Since heat rises it was coming up the stairwell and making the RCS think it was warmer in the great room than it really was, by 2 degrees on average.
So, I hung a standard mercury thermometer in the middle of ceiling in the great room and let it set for 2 hours. I then calibrated the RCS to match THAT temperature rather than what it was reading at the top of the stairs.
Now the RCS actually is reacting to the ambient air temp in the great room instead of the air movement from downstairs and now keeps the greatroom exactly where I want it.
Next problem, we close the bedroom door at night and even with 1 of the two heat vents closed completely and the 2nd 1/2 closed it was still getting too hot to sleep comfortably, SO. I again hung my mercury thermo from the ceiling right in the center of room to get the ambient air temp.
I then installed a Templinc in the bedroom and checked the descrepancy between the two which was 4 degrees. In my 24x7 monitor program I check (every 15 minutes at night) the reading from the templinc, apply the 4 degree offset to get the actual ambient air. If the templinc rises above the desired 67 degrees the program sends a command to the RCS to lower the setpoint by
1 degree which results in a drop of course in the greatroom but keeps the bedroom correct.
We get up at 5:00am so at 4:30am the program moves the setpoint on the RCS back up to 70. At 5:30 HCA does the morning alarm sequence by sounding an X10 chime at 5:00am, 5:15am and again at 5:30am (built in snooze) but, when we get up the temp has risen back to the desired 70 degrees and since the bedroom door is now open the whole house stabilizes pretty quickly to the desired 70 degrees.
We both leave the house at 7:00am so at 6:45 the program sends a setpoint of
65 degrees to the RCS where the house remains until 4:00pm at which time it sets back to 70 and when I get home at 4:30 the house is right where I want it to be.
Just thought you all might be insterested in a 'poor mans' zoned HVAC system. The key was getting the ambient air temp