Avoid Unvented Gas Heaters

unvented heaters
by Catherine Silver

You WILL experience a residue all over your house if you run an unvented heater. We supplemented our radiant heat system running the unvented heater periodically in the cooler side to our house in the kitchen to try to offset the higher gas costs of last year, but it isn't worth it. I will be removing the unvented heater. Even with the window slightly cracked I had a film on all glass window surfaces- so you know it is everywhere. Thanks for posting this article.
(On another note- Our radiant system was a retrofit situation- I don't recommend it under certain existing floors. It is excellent in the concrete pours but far less efficient under existing floors )

Vent free [ROOM VENTED HEATERS FIREPLACES & GAS LOGS
by Perry Bumpers

You are right on target with your informatiom about ventfree [ ROOMVENTED PRODUCTS] It does not matter if it is a ventfree log , space heater or ventfree fireplace. The results are the same when a ventfree product is used to heat with . Bad smell ,water running down windows & walls, discolored walls & celings. SOOT SOOT & more SOOT [soot is very common with ventfree logs and fireplaces ]. People complaining with more headakes , sinus problems ,colds sore throats. The list just goes on and own. Most information that the consumer is given about ventfree is incorrect. They are made to belive they can use the ROOMVENTED HEATER , LOG. OR FIREPLACE TO HEAT THERE HOME WITH. All the consumer is told is 99.9% of you heat comes in the room. You loose no heat up you flue. Heat for pennies a day. Save big $$$$ heating with ventfree products. It always about the heat. Hardly anyone that sells a ventfree [ ROOMVENTED] product makes the customer aware of sizeing guidelines for ventfree products. That they should be used no more than 2 to 4 hrs in a 24 hr period. Never to be used as primary heat suppliment only. That you must provide proper combustion & ventalition air. New tight build homes may require 2 windows open to provide enought combustion air. This is not a concern when a directvent fireplace insert or stove is used. The air for combustion comes from out side you home. Vent free products burns up the good air in the home and dumps the trash out in the room where your family lives. YOU LIVE IN YOU FIREPLACE WHEN YOU USE A VENTFREE IN YOUR HOME. Probably 75% of all ventfree products sold are to large fo the room they were installed in. There are 1000's of homes that have a window A/C unit & a ventfree product of some type that is there only heat source. EVEN THOUGH VENTFREE IS NEVER SUPPOSE TO BE SOLD OR INSTALLED FOR PRIMARY HEAT. Do your research you may have to go around the world to get the correct info . usually some where other than the gas company or the person selling ventfree products. GOOGLE DANGERS OF VENTFREE. You will have to dig a little but some good info there. I have been in the hearth industry for over 20 years now. I would never sell my customers a ventfree product . I would never put a ventfree in my own home. Sure I could have jumped on the band wagon made some money. My customers & there homes & families are more important to me than the bottom line. My company and my dealers that I sell to have replaced 100'S of ventfree [ROOMVENTED] products in the area's my personal stores are in we have replaced well over 400 ventfree LOGS & FIREPLACES with directvent products. We have added many more fireplaces in homes where they have removed there space heaters as well. They we all removed because of these reasons. The consumer would say. The heat is great. BUT I can't stand the smell. I have this white chalkey film all over my brick ,stone , tile on the front of my fireplace. [just think about what your breathing.] I get headakes all the time when my heater is on. It sooted up my house. There is so much water. I have to keep rags laying in my window seals. It seems my children are sick from the time we turn the fireplace on till the time we stop unsing it in the spring. I have been hearing these stories for over 20 years now. I have worked hard to inform the public in the areas we work. Ventfree products are not good for our families , homes, or our health. I have had other companies try to lable my company and my self as A liar , exstreamest, alarmest, & just a plain nuts . What amazing to me alot of these comments are made by those that I'm helping to sell 1000' up on 1000 of dollars of there gas. Why is that. Could it be like alot of other things in this country today. They don't want the public to know the truth. Do the research . Its just sad that you can't find out correct information by most who sell the ventfree ROOM VENT products. Make sure you always buy a vented product. I would choose a directvent with the sealed combustion chamber. Don't be mislead .Alot of directvents on the market can heat a home . The up front cost for a directvent may be a little more but it elimates all the issues that are caused by a roomvented ventfree product. The directvent can be used in any room . Can be used 24 hrs per day . Also they don't cost any more to operate than a ventfree product. Most people that sell ventfree try to may the consumer belive ventfree use much less gas. The orfice measures the fuel that comes into the fireplace ,log or space heater. If it a 30,000 btu orfice it 30,000 btu's. vented , unvented or directvent. That is all the gas per hr that will be used.. Gas is a great product it provides great heat. It just should always be vented.. THANKS, for trying to help inform the public about THE DANGERS OF VENTFREE PRODUCTS.

unvented heaters
by Paul Hempel

Mr Wilson's article is spot on recommending avoiding vent free gas appliances, but there are some other negative issues he didn't touch on that can make them even less desirable.

The first is that all the gas industry research he mentions is done under ideal conditions, which of course don't exist in the average home. If the logs are even slightly mis-aligned, if there is any dust or pet dander on them, the chances of sooting and the production of toxic by-products will go up dramatically.

And secondly the vent free appliance uses room air for combustion. If that room air is contaminated in any way with say paint fumes, cleaning products, or off-gassing from new carpet or other building materials, all those contaminates are mixed, burned and sent into the room air as a potential witches brew of unknown compounds for the occupants to breathe.

We all understand that the one downside of tighter, more effecient housing is the potential for indoor air quality issues. To install a room vented appliance in a tightly sealed home is sheer folly, and should be actively discouraged by all industry professionals.
Respectfully,
Paul Hempel

Impact of burning contaminants in the house air
by Alex Wilson

Paul,
This is a great comment on the risk of using household air with contaminants as combustion air then venting that into the room. I had never thought of the issue of burning existing contaminants and, in the process, making them more hazardous. Another important reason to ban--or at least avoid--these combustion appliances! Thanks for the input. -Alex

Gas Fire logs
by Thomas

So what are the options / do I put glass windows on the fireplace and vent out the chiminey using the radiant heat source. How can I get the maximum efficiency for this situation.

unvented heaters
by Paul Hempel

Thomas,

Fireplaces tend to specialize in maximum aesthetics, not maximum efficiency.

Burning with glass doors/windows shut will cut the energy coming into your room tremendously, while still drawing unacceptable amounts of room air out the chimney. They will tend to smoke up until you can barely see the fire. Neither you nor the fireplace will be happy.

If efficiency is your goal, consider installing a fireplace insert with a full liner. Inserts require just a fraction of the room air for combustion that an open fireplace would consume. Modern inserts also have large viewing windows that stay relatively clean. They allow you to both enjoy the fire view, and heat your home efficiently.

Your other option is to use the fireplace only during cool spells in the spring and fall when your furnace will not have to waste too much energy heating up replacement air lost to the fireplace. A tight sealing damper and glass doors will help save energy when the fireplace is not in use.

While many of us are open fireplace enthusiasts, open fireplaces are an archaic technology, and likely don't have a place in a tight, modern home striving for energy efficiency.

Paul Hempel

GAS INSERTS
by Perry Bumpers

Thomas , If you want the most efficiency from your fireplace . Use a directvent gas insert. This way all your combustion air comes from out side of your home. Some directvent inserts are at 80% efficiency. Directvent product are the best choice for our families ,health & our homes.

Perry Bumpers

Unvented Gas Heaters
by Anonymous

Can an Unvented Gas Heater be converted to a Vented one? How is this done.
Thanmks, Bob Franks

No
by Martin Holladay, GBA Advisor

Bob,
No.

unvented gas heaters
by Dave Maupin

For the past three years we have used an unvented gas log heater on the main level and an unvented gas wall-mounted heater in the basement. Both are 30,000 btu units. While there is no noticeable odor when we are inside the house, we have noticed a distinct odor upon entering the house. In addition, a film gradually appears on the windows when we use the heaters and, as we have a number of floor to ceiling windows this presents a problem. This year I have noticed a sensation in my lower throat and lungs, much like a sore throat others have commented on, that isn't there in the seasons when the heaters are being used. We're planning to look into units that are vented from the outside. Any suggestions?

It's hard to make a recommendation without inspecting your house
by Martin Holladay, GBA Advisor

Dave,
Clearly, it's time for you to stop using unvented heaters.

Most homes are heated by a vented furnace or a vented boiler. It's also possible to heat a house with hydronic radiators served by a water heater, a vented wood stove, or with an air-source heat pump (for example, a mini-split). There are lot of ways to heat the house, and your choice will depend on a variety of factors, including fuel availability and the configuration of your home. One thing's for sure: you have clearly explained why no one should try to heat a home with an unvented heater.

unvented heaters
by Mark

We have unvented logs in the house we bought and we haven't had any trouble with them so far. Of course they are in the formal dining room and we are lucky if we use them once or twice a month, and then only for a max of a couple of hours. For the amount we use them I'm not sure it's worth switching to get a new gas insert. Our chimney is "decorative" only. We we have to have it lined in order to use a vented gas insert?

Decorative chimneys
by Martin Holladay, GBA Advisor

Mark,
A decorative chimney is not a chimney; it's more like a theatrical prop.

Of course, if you have a new fuel-burning heating appliance installed, it will need to be properly vented. Modern venting options include metal flues (stainless-steel or galvanized) or plastic vents (for condensing appliances). Building code requirements for flues and chimneys are strict. If you are unfamiliar with code requirements, don't guess at venting details. Hire an HVAC professional.

Open the flue
by George

Hi,
We have ventless gas fireplace logs. We don't run them alot, but I'm wondering if there is a way to sort of mitigate the potential problems with ventless logs. For example, what are the consequences of running ventless logs with the flue slightly open? I understand that the flue would then need to be closed when the fireplace is not in use, or install glass doors that can be closed when it is off, but are there other issues? Besides the loss of some heat, do they not function properly ins some way, or cause more sooting, etc? Thanks.