Question about insulation on mains in basement

berm

I recently insulated all of the main lines in my basement. Strangely the house (upstairs) actually feels colder than it did before insulating. I have an oil fired steam boiler running on a Heat Timer. Is it possible that the insulated pipes are satisfying the Heat Timer's indoor element faster than the uninsulated pipes and in effect creating a short cycle? Should I simply increase the cycle time?

nicholas bonham-carter

heat timer problem

i would think that the heat timer indoor element should be sensing the arrival of steam on an insulated pipe more accurately than if the pipe were bare. i presume it uses the tekmar style of comparing indoor and outdoor temperatures and arriving at some sort of run-time percentage for the boiler. is your building too big to use a thermostat, so you could compare the result? when you say it feels colder, have you measured the temperature with a thermometer? no doubt the floor feels colder over the newly-insulated pipes.

there should be a display which will show you the temperature sensed by all the sensors, so you could see if one of them is not showing a realistic output. you can compare these temperatures with a digital thermometer and see what may be wrong.--nbc

Dave in QCA

Heat-timer

First, all of the points that Nicholas has made are correct.

Some additional thoughts-- I studied various heat timer models when a few years ago and ended up going with the Tekmar unit.  At that time, there were several Heat-timer models that did not have an interior space sensor.  So, my question is when you refer to the interior sensor, are you referring to the sensor at the end of the steam main that indicates when steam has been established?    What model do you have?

When you insulated the mains, you reduced the total effective radiation of your system.  This is a good thing because the excess heat going into your basement was mostly wasted.  A great deal of it would be absorbed through foundation walls.  But, some of the heat emitted in the basement would actually warm the floor of the first floor.  This useful part of the heat lost from the uninsulated mains is no longer there to assist in heating your first floor.  So, if you do not have an indoor sensor, by all means, adjust the heat timer to produce the space temperature that you desire.  If you have a interior space sensor, it should compensate for itself.  And if this is the case, perhaps you sense that your space is not as warm as it was simply because the floor is not as warm as it was.  In either case, there is no harm in making the necessary adjustment to make yourself comfortable.  You still be saving money because of the heat that is no longer going into the foundation walls.

berm

Heat Timer

Thanks for the responses. I am using a Heat Timer Model EPU-CH (blue panel, 3 lights).

The indoor element is a strap on attached to the last return line in the basement. There is also an outdoor sensor that reads the outside temperature. I think the point about the flooring on the first floor not being as warm due to the insulated pipes in the basement may be on the money. I'm going to monitor this and possibly try increasing the heat adjustment slightly to compensate.

Dave in QCA

Heat Adjustment dial

Yes, I was just reading the manual.  Your model does not have a interior space sensor; it runs base on outdoor temperarue only one the steam cycle has begun, as determined by the interior sensor on the furthest reach leg of the steam line.  Since you have slightly changed the heating characterstic of the building, the fine turning should be with the Heat Adjustment Dial.   You are correct.

malex

Radiant floors

My experience from insulating the mains is similar in that I miss my radiant kitchen floor. But it hardly seems worth over heating the basement for it.

Also, from my half bath that sits on a unisulated crawlspace I have come to realuze how much floor temperature rather than space temperature has to do with comfort.

Jamie Hall

You did?

makes quite a difference.  If you don't believe me, ask my cats -- who won't move from a spot directly above the boiler so long as the boiler is firing!