space heater

krisman · December 2009

I have an enclosed back porch with quite a few windows, it measures about 25 L x 10 W x 10 H. the sunlight through the windows are just not enough to heat it well and as much as i hate to i am going to have to get a space heater to help the gas furnace, the furnace runs non stop at 74 degrees. I have read where space heaters with built in fans work well and i also know that you guys reccommend oil filled space heaters. I just dont like the idea of burning petroleum in the house. I am new to them so i dont know much about them, so tell me everything. Can you replace the petroleum with plain old vegetable oil? i would feel much safer burning an all natural oil.

BB. · December 2009

Re: space heater

You can compare costs with the Fuel Cost Comparison Calculator--But, if you have natural gas (or even propane), that would most likely be much more cost efficient than using electric heater(s) of any time (unless you only need to heat the porch a few day out of the month (guests, parties, etc. where $5 for 4 days a month is OK and for $5 a day for 30 days a month is too much).

Bay, borrow, beg a cheap/simple 1,500 watt electric heater and put a Kill-A-Watt meter on it for 24 hours on a cool day and see how much it costs you to operate.

Then compare the estimated fuel costs between the electric heater vs natural gas/propane.

My guess is that a good sealed combustion direct vent wall heater or even sealed combustion direct vent gas fire place if it would add to the decor of the room.

But, back to fundamentals--double pane windows, storm windows, lots of insulation, weather stripping, insulation in ceiling/walls/floors, etc. would be my first place to spend the money. I don't know how much glass you have, but possibly replacing with custom (factory built) double pane windows with low E glass may be a big help too.

Possibly building foam insulated "storm windows" for every other window, or to block windows with "uninteresting views" in the winter would help steam heat loss too.

One or two electric ceiling fans to drive heat from the ceiling down to the floor may help too (especially if the heater(s) are not forced air).

-Bill

krisman · December 2009

Re: space heater

well we do have energy effecient windows already installed, and i dont kow why it is so cold . probably because there is no vent installed. the ceiling slopes so theres no way to install fans. i have heard of heat bulbs and we do have a couple of light fixtures back there. would it make sense to get a couple of heat bulbs, put plastic over the outside of the windows and see what it does? what there is also, are a set of full lenght pull blinds where the sliding door used to be to the back porch which i have pulled and closed, it may help a bit but not a whole lot. im running out of options, the porch is cement covered with indoor outdoor carpet. i wanted to make a sunroom enclosed with glass but it was too late, they had done started on it.

BB. · December 2009

Re: space heater

Your best bet energy wise is probably to install a nice set of double pane/weather stripped french doors (or other type door appropriate for the space where the old sliding glass doors were) and only heat the sun room when needed--as opposed to now which is the house heating the sun room through the old sliding door space 24x7 (if I understand you correctly).

I installed a set of Anderson french Doors and was very happy with them (no cold/hot air leaks, well insulated).

Single pane widows are around R-0.85 . Double pane glass windows only run R values of ~1.5-3 (3 if low E glass, U=1/R), and even the simplest insulated 2x4 stud wall can have R-15 insulation.

So, if your home had wall/ceiling insulation, by adding the sun room, you have made a huge cold sink with "poor" insulation of the glass. Keeping the heat in the home, except when the sun room needs heating, is probably the most cost effective plan.

Then looking at heating alternatives (direct vent heater, perhaps a mini-split A/C&Heat-Pump system (should be reasonably efficient down to near freezing, and if it gets over heated in sunny weather, you have a small A/C to help....

I am getting stumped at this point... Adding plastic film (sort of like an additional storm window) may help--but I am not sure that it would be practical for the long term.

But, I am probably getting out of my depth here--I just don't have the cold weather experience that other here may be able to help you with.

-Bill

BB. · December 2009

Re: space heater

I guess I should add there are heat loss calculators like this one... Perhaps one of them would help you size/understand your heat losses.

If you decide that you need some prossional help... A heating contractor should be able to size an aux heater (and even your local utility may have a efficiency assistance program too).

-Bill

icarus · December 2009

Re: space heater

Just an FYI,

Oil filled heaters don't burn oil, they only use oil to add thermal mass to even out the heat.

Tony

niel · December 2009

Re: space heater

if your furnace runs all of the time at 74 degrees you are in a pickle as the worst of winter is yet to come. there may be something wrong with your furnace and i recommend you get it checked and everything evaluated by a professional (hvac). if it checks out then suspect major air leaks in your home that need addressed, but i would imagine that given the current weather conditions that even with a major air leak that it should shut down periodically in spite of this high loss.

krisman · December 2009

Re: space heater

would the type of filters we use in it be dragging the heating power down some? if the filter is too much mass, wouldnt that stop the heat from blowing out well?
also we have a couple of vent coverings over a couple of the vents, the plastic ones you put over vents to divert the air in a different direction, cant think of what theyre called right now but would that have anything to do with it?

krisman · December 2009

Re: space heater

oh and what about some kind of thermal drapes over where the sliding door used to be? cause they removed the track and everything whne they puut the carpet down

niel · December 2009

Re: space heater

those items may influence how long a furnace may run, but i doubt that they would cause the furnace to run constantly at 74 degrees for this time of year. rather than my speculation, what was the low/high temps you are talking about for outside while the furnace was straining at 74 degrees?

BB. · December 2009

Re: space heater

It sounds like you are taking about air vent deflectors.

Depending on how much the restrict the air flow, they could reduce the volume of the air from that one or two air vents--but if they are like the picture in the link above, I doubt it.

Sort of a related issue related to force air systems... Yes, you can block airflow with a deflector or local air filter. The rest of the air goes out the other 5-10 vents.

So, adding a "local filter" will probably dramatically reduce air flow (and heating/cooling). If you need filters, generally a forced air system will have a location to install a large filter in the air return duct or somewhere near the blower assembly. They are designed assuming you have a filter in the main air duct somewhere (and the motors may overheat if no filter--because of the excess amount of air moved without the filter restriction--actually loads down the blower motor more than designed).

However, it is possible to have the another problem.. Say that somebody removed the vent cover from the duct work. Now, there is no restriction to air flow. And all of the hot (or cold) are flows out of the one vent and all of the rest of the other vents are "starved" for airflow.

Generally a forced air system is designed to expect a certain resistance to air flow so that when you place grills and such on the end of the duct works around the system--they all "experience the same amount of pressure" and all similar grills will output the save CFM (cubic feet per minute) air flow throughout the duct-work system.

So, say you had a cold (or wet that needed to be dried out) basement at one time. Somebody took off the grill or two in the basement and forgot to put them back on... Now, most of the heat (CFM's) are dumped into the basement and the rest of the vents (and rooms in the home) are now starved for heat (or A/C in the summer).

Putting some sort of thermal drapes across the ex-doorway would be a great help in keeping the rest of the home warm. In my previous small home, I used to put 7mil (heavy plastic sheeting used as a drop cloth taped round an expanding shower rod) across the hallway to the bedrooms. We had a wall heater in that area and it did a very nice job of keeping the heat in the back part of the home when we were not using the front of the home.

For our case, we wanted to keep the rest of the home unheated to reduce costs when the rooms were not being used. And the hallway was not visible to the main part of the home--so the clear plastic was not a huge issue hanging in the small hall.

Depending on how much natural light you want in your home, you may have a choice between heavy/but dark thermal drapes. Or try some sort of light colored shear white/colored drapes that let light in a block most of the heat loss during the day (perhaps two sets).

Depending on how cold/windy your home is--that is why I also suggested installing French Doors--so you could get light in without letting your heat out.

Closing off the old doorway, of course, will not help you heat the sun room in the winter. That will require another solution (local heating, better insulation, etc.).

-Bill

westbranch · December 2009

Re: space heater

Is this a "New Build" or a renovation. If new you have a major problem,and should go back to the builder... if a reno, there is something that has been done to the heat system as most furnaces run about 25 - 40 % of the time, depending on ambient outside temperatures...if sized correctly.

Can you give a more complete description of the house. include the furnace (?? BTUs) oil, gas or electric.

which vents are actually blowing hot or warm air etc..

HTH
Eric

krisman · December 2009

Re: space heater

i just mean that all i have right now separating the enclosed back porch and the kitchen are blinds that were used for the old sliding door befor it was removed. putting up thermal drapes in place of the blinds would help wouldnt it? the temp outside when the furnace ran non stop was 32 and under. right now it is 37 outside and the furnace has kicked off for a few minutes. so at least it isnt running all the time. and i did look for a place in the central unit to change the filter but could not find a place, so if the vents dont really need a filter then no wonder it is running so much

BB. · December 2009

Re: space heater

Generally, blocking one or two vents with filter cloth (I guess that is what you did) will tend to "unbalance" the heating. In the rooms with the filter--those rooms would probably be on the cold side. And/or the other rooms would tend to be on the warm side because all of the hot air is being shunted to the other rooms.

Depending on where the thermostat is located, The room will be 72F (or whatever you set) and the other rooms will be, on average warmer or colder than the thermostat depending on air flow and damper configuration).

If you have too little airflow through the central furnace (I am assuming natural gas or propane), the heat exchanger may run hot and the limit switch may turn off the flame to keep it from overheating (reducing the total amount of heat/BTU's through the furnace; reducing efficiency; and possibly not able to keep up with heat in the house because the flame is not on 100% of the time).

Note, I would guess there should be a filter somewhere in your furnace intake path--or in some older furnaces I have seen, you unplug and lift up the blower motor tray, and find a filter right under that tray (or, if you are not the first owner of the home, somebody else took out a plugged filter and never replaced it).

In the end, shutting the 6-8 foot hole in the wall to your sun room should help keep heat in your home, reduce furnace cycle time, and reduce your heating costs.

But, that will leave you with a cold sun room (no heat from house)--unless you address that issue.

I am not a HVAC person--at some point it may be worth your time and money to get your furnace system looked at. There is probably nothing wrong--but if you cannot find a filter, either there is a dirty system filter that maybe reducing airflow (and reducing heater efficiency) or there is no filter which may be spreading dust through the home and air ducts.

There is only so much I (and others) can guess at in these posts.

-Bill

westbranch · December 2009

Re: space heater

I re-read posts 1 , 3 and the last one... from what you are saying the furnace used to keep you warm and toasty...

now that the sliding door is gone so is all your heat... conclusion is that the heat is getting out of the house either thru the 'hole in the wall' (where the slider was) or through the spaces around the glass in the porch. Most probably in the ceiling of the porch as heat rises , and when in sealed area/room will 'build up' at the top and gradually work its way down to near the floor. If this is not happening you have a 'hole' somewhere near the top that is letting all the heat out, find it seal it and you ought to be warm depending on the ability of the furnace to heat the additional space..

you need to know that glassed in areas (porches) are notoriously hard to 'heat' 24/7 due to the poor insulating properties of glass... this may be a losing battle for your existing /any furnace.

HTH
Eric

krisman · December 2009

Re: space heater

thanks for the advice, but it really isnt a sunroom at all. its just enclosed with 5 windows, maybe 6. i did want a sunroom but i really had no say, so this is what we ended up with. there are blinds on each window and it does ok in the summer, but the winter is very hard to heat cause there are no vents to get any heat to it. oh and there are 2 doors that lead to the outside too, they both have draft guards but still cold air would find a way to get it, or at least i would guess right? ive thought about putting a fleece blanket over each of the doors, would this help any? and yes the furnace worked great but that was back when we had no filters in each vent, then again the furnace is 20 years old. and with a split level heat pump, does this mean that it would have to fit in the window kind of like a window ac?

icarus · December 2009

Re: space heater

Save ourself some trouble, go here:http://us.sanyo.com:80/HVAC-Single-Split-Systems and read how they work.

Tony

westbranch · December 2009

Re: space heater

weather - 34 C, sunny and no wind this morning..

I would suggest a nice set of french doors to close off the hole for the winter, end of problem until you want to use it in the winter..

As an experiment can you get some heavy plastic and sealing tape to close off the 'hole'. this will tell you if you have a furnace problem if the house gets warmer...

Is the new room an old porch? has it been well insulated top, bottom and sides? injectable foam sealant used around all windows and doors, etc, etc? the 24/7 comment is what I am focusing on...

HTH
Eric

krisman · December 2009

Re: space heater

i think i have found the cause of why the furnace isnt heating to its full potential. the enclosed back porch has 2 doors that lead to the outside. on one of the doors, it is sealed at the bottom but starting about halfway up, it doesnt look sealed. it is bad enough that the top corner of the inside door has small cobwebs where little spiders have gotten through i guess. its cold enough that the door handle is nearly freezing to the touch on the inside. it has to be the cause because that is the coldest part of the house. now what i need to know is what do i need to get to seal the top of the door? i would like to stay as environmentally friendly as i can but i know most insulation isnt, so im open to suggestions.

BB. · December 2009

Re: space heater

You can get a can of insulation foam at the local home store and inject it into gaps behind window/door frames. Can be very messy but it can work. You need a good sized crack/access point to get the tube into the frame area. Also, don't put too much in... It will expand its volume several times over the next few minutes before it hardens... Too much can cause problems (leaking out under pressure/pushing something out of alignment).

You also need to close up with drapes or french/silding doors in your existing opening. Will make the energy losses going out through the porch/sun room less important (at least for now).

-Bill

krisman · December 2009

Re: space heater

thats what i thought you would say. would that just be a temporary fix or will i need to install a new door or frame in the near future? is this stuff toxic? just want to make sure so i will know to wear a mask. i hate chemicals but it has to be done.

BB. · December 2009

Re: space heater

It does not appear to be very toxic (no smells that I can tell once it cures). Fairly aggressive glue-like properties--so it is a pain to clean up or disassemble later. I used it on my door/window change outs (seal up old sash-cord/spring balance areas, etc.) for a couple homes and plan on the sealant being there for decades to come (after that, it will be somebody else's problem).

Get fresh cans--If they get a year on them, they don't seem to work anymore (at least the ones I have used). A used can needs to be tossed when you are finished (can't save for use next week).

Can't take UV--so cover (wood, metal, etc.) to protect from sun.

No matter what you do--you probably are going to need to seal that old sliding glass doorway with something. The cold leaks around the doors are not helping--but it is probably just a small part of the problem (heat loss).

-Bill

westbranch · December 2009

Re: space heater

You want to get the 'window and door ' variety of foam, also called low expansion. no it is not toxic but sticks worse than anything else you will meet up with, once cured it has to be mechanically removed... wear disposable gloves and safety glasses. Excess has to be cut off
inject in stages and wait at least 15 minutes , better a half hour before reapplying..
HTH
Eric

krisman · December 2009

Re: space heater

i wanted to see what everyone thought of this, i know it is a little expensive but supposedly green, http://doitbest.com/Adhesives+and+Caulk-Henkel+Corporation-model-1183480-doitbest-sku-276515.dib

and when i do this, is this going to glue the door to the frame? because thats where the space is, between the door and frame. and whats going to happen when i spray this on and let it set, and then having to open the door eventually, wont it be stuck then, or when i do open it wont the foam break off?

Solar Guppy · December 2009

Re: space heater

Nothing "green" about that, its run of the mill expanding foam ... the "Great Stuff" brand is the exact same stuff and cost less than 5 bucks a can at you localHD or Lowes retailers

icarus · December 2009

Re: space heater

From the link: "minimal expanding urethane foam sealant"

$22 for 29 oz can, plus shipping.

Same stuff as in the "great stuff" or "Geocell" foams for about 1/2 the price.

I think the only thing "green" would be your money in their pocket!

That said, sealing air leaks slowing infiltration is one of the easiest, cheapest way to save energy, hence being green.

Tony

krisman · December 2009

Re: space heater

yes but if it eats your lungs up with the off gas that it emits, its worth paying a little more for the safe stuff. the only problem is i cant find any eco friendly spray foam anywhere. if this stuff is hard to remove, wouldnt sticking pieces of fleece in the gap or something like that do the same thing? i started to put up a fleece blanket over the whole inside of the door but i couldnt find anything to hold it up. i was afraid to tape it up fearing the tape might not come off, i dont like the idea of nails messing up the wood frame.

Solar Guppy · December 2009

Re: space heater

I have never read that urethane foam sealant has any off gassing. Its used everywhere in new construction today. Your falling for marketing hype that tags something with the word "green" to sell it for more. you link is the exact same stuff at home depot sells for $4.79 can, just a different label

krisman · December 2009

Re: space heater

yeah i guess youre right. ill stick with the great stuff and the thermal drapes.

Now if someone can just tell me how to stop one of my bathroom lights from flickering, ill be ok. sorry, thats another thing i cant seem to find the answer to online.

icarus · December 2009

Re: space heater

Buy a copy of "wiring simplified".

dwh · December 2009

Re: space heater

krisman wrote: »

yeah i guess youre right. ill stick with the great stuff and the thermal drapes.

Now if someone can just tell me how to stop one of my bathroom lights from flickering, ill be ok. sorry, thats another thing i cant seem to find the answer to online.

If it's fluorescent, first check that is has adequate incoming voltage, then probably replace the ballast and/or the lamp sockets.

If it's incandescent, check all connections for tightness. In bathrooms, corrosion is a common problem, so sometimes you have to replace the switch or the socket in the fixture.

space heater

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