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Heating Bedrooms

We live in MA so winters are long and cold. Our master bedroom is above the garage and it is so cold in there that we do not use this room for the whole winter which is about 6 to 8 months a year. My husband I move out to a smaller room/office. The house was built in 1938 so for heating we have radiators. There is one in there which works fine but it is so cold that the heat does not last long. Also, the thermostat is in the dinning room down stairs so it could be warm 70 degree down stairs but it would be 50 degree in this room. I would like to use this room as our pemanent bed room but not sure what can we do about this.

Also, my elderly mother lives with us and I would also like to heat her room. It is not as cold but for her it is cold. She keeps her room closed most of the time to keep the room warm. we tried the space heaters but were not worth it. They did not heat the room enough. We are thinking to put elecric baseboard heaters in her room. Would this work? What kind should I be looking for?

By the way I love to watch your shows.


Re: Heating Bedrooms


This type of room (over a freezing garage) has always been a real problem to heat.

When you consider the cold slab that is providing radiational cooling (like a block of ice) right below the room, the problem of heating such a room is difficult, but not impossible to overcome.

Your first point of attack should be to create as tight an "envelope" of insulation surrounding the room as possible.

That means having insulation blown into the exterior walls and attic (R19 for the walls and R40 for the attic).

The floor between the garage & the apt has to be hit with spray insulating foam to get an airtight seal & maximize insulation value between the garage & the bedrooms.

Consult the Yellow Pages under "insulation" to get estimates for this work---it's usually only a few hundred dollars---the cost is well worth it when savings in fuel and cooling over the years are considered---not to mention the comfort of the occupants.

You say you have "radiators", but what type are they---hot water or steam???

And are they large enough to heat the rooms (radiator sizing)???

And is the water (if hydronic) hot enough to provide adequate heat for the rooms???

You can check the temp of the rad water coming into the bedrooms by holding your fingers onto the incoming pipes at the rads as they heat up---if the water is hot enough (180 degrees) you will not be able to hold your fingers to the piping for more than a second or two---if there is not enough heat in the hot water supplying the rads, you can hold your fingers indefinitely on the piping.

Sizing the rads:

Assuming the rad water is hot enough (180 degrees), you have to "size" the rad in the room to make sure it is large enough to heat the room.

For this, 170 btu/hr for each sq.ft. of rad is assumed---this is multiplied by the # of rad sections.

Thus, a rad that is 24 sections and 1/2' wide and 3' high = .5 (1/2 ft.) X 3 = 1.5 sq.ft. X 24 = 36 sq.ft. X 170 = 6120 btu/hr for the heat output of this rad.

Next, multiply the sq. footage of the room:

A room 15 X 10 = 150 sq.ft. X 50 (heat factor) = 7500 btu/hr heat need for this room---this means the rad is too small to heat the room & another rad has to be added.

Adding additional rads can be done with both hot water radiators, or steam radiators.

If hot water, baseboard can be substituted, as this is easier to install in some cases.

The "heat factor" used in these calculations is arbitrary, and can be anywhere between 30 btu/hr to 70 btu/hr, based on window condition, insulation factors, height of ceilings, radiational cooling, etc.

An extensive heat loss calculation using the free site below by Slant/fin should be done to get a more accurate result.

Also Google "cold room over garage" and "cold room above garage" for additional background info.

Having the t-stat in another room is problematic---this has to be solved (if it is hot water heat) by putting the bedroom & mother's room on a separate zone with it's own t-stat---not that hard to do if it's hot water heat.

This would give much better temp control of the above-garage rooms.

Please post back with the additional info requested.


Re: Heating Bedrooms

Thanks for your reply. It's excellent. We were wondering if we should have it done now or wait till summer. Someone told us to wait till summer which we can certainly do. Also, can we have all the outside wall sprayed. The house was built in 1938 and I am not sure if they put enough insulation. Again thank you very much for your suggestions.

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