Reducing heat above gas fireplace insert
Hi there-
I'm looking to get some advice on how to reduce the heat on the surface directly above our new gas fire place insert. We just finished the upgrade and really love the look and design (see photo), but the surface is so hot (250-270 F) that it's cracking the mud and plaster in more than one place (only one is on a seam)
Here are the details:
The unit is a Valor G4 with no fan
The surface of the fireplace was prepped with hardibacker, glued and screwed to the sub structure with a hot mud float to even out the surface.
Venetian plaster applied to finish.
Looking for suggestions/advice to make sure we're using the right materials to prep the surface before the plaster is applied and also to reduce the heat on the surface above the fireplace. Obviously we can turn down the flame to lower the temp, but it would be great to have the option of using all the features of the gas insert and not have to limit its flexibility.
Thanks in advance for the advice and suggestions.
Comments (17)
PROSabrina Alfin Interiors
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Austin Lee
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Comments (5)Andrelaplume2, a few comments. You do not state where you live. I have a similar situation. I have a 20 year-old, 1700 square-foot, all-electric, split foyer home in Baltimore. I have been in the house for 5 years. The heat pump is original Trane (we should count our blessings that they have lasted 20-plus years). I have a masonry fireplace in the below-grade family room. I have allergies (dust, pollen, grass, weeds, cats, etc - I get an allergy shot every 3 weeks and have been doing so since childhood). I have been using my fireplace w/one-of-a-kind wood-burning insert to suppliment the heat pump. The insert raises the temperature of the family room from 65 to 72 degrees. The thermostat is in the living room and set at 68. The layout of the house is not open so the heat does not directly go to the second floor living area (where the thermosat is located) and bedrooms, but it does add BTU's to the house and heats the floor of the living room. The fireplace does not affect my allergies. Neither does mowing the lawn. Are you so sure of the effects of wood-burners on your allergies that you write-off the best sources of heat from your masonry fireplace (wood/pellet insert or stoves)? Propane and electric resistance heat are the most expensive sources of heat - and by a large margin as compared to other sources of heat. I run the house fan in the summer only. This does 2 things. First, it helps to move air in the summer (I have ceiling fans also). Second, the wife doesn't know when the A/C compressor cycles off so there is less of a chance that she is playing with the thermostat. You can run your house fan in the winter with your new heat source and see how it works. I find that there is cold-feeling air blowing out of the vents in the winter time when the firepace is going in the family room (there are no return vents in the family room in the ceiling). Is there a return vent in the ceiling near your fireplace? I agree with Bob Brown from the HVAC Forum that your basement heating should be done with your current HVAC system. When you replace your current heat pump, you can increase it's capacity if needed and add ductwork to your basement. My opinions....See MoreGas fireplace insert vs. house heat
Comments (12)I clipped this post from a previous discussion on gas inserts to provide additional info on the subject. Posted by: renron on 12.19.2006 at 07:28 pm in Fireplaces Forum First, DON'T install a ventless fireplace!!! Even though the MFG.s will tell you the exhaust fumes are OK, do you really want to breathe them? Many people end up with Major Headaches and chronic breathing issues. Does it sound like a good idea to breathe burnt exhaust gasses? B type flue(vent) pipes are dual thickness pipes. A pipe inside another pipe, suitable for use at 1" or more to flammable materials. Outer casing pipe is sealed and will not conduct air. D (Direct Vent) type flue(vent) pipes are also dual layers but they are capable of exhausting burnt gas through the inner pipe and importing exterior(outside) combustion air for burning. Think of a straw inside a larger straw. Inside straw blowing, outside straw sucking outside air for combustion. A fan is usually used to help exhaust the burnt gasses. Details below: B-Vent (Natural Vent) gas fireplaces are designed primarily for decorative use. Generally they produce a larger and more realistic yellow flame. B-vent fireplaces are sometimes available without a glass window, so many homeowners are attracted to this design because of the open, realistic flame effect; some models do have a glass window so the existence of a window on a fireplace does not define its product classification. Natural vent gas fireplaces use room air for combustion and vent fumes through a vent or chimney that must terminate vertically above the roof line. The key to determining whether a B-vent fireplace will meet your heating needs is to check the manufacturer's listed efficiency rating (gas consumed x efficiency = heat output). While efficient, heater-rated B-vent fireplaces do exist, many lower quality "builder grade" fireplaces have no efficiency rating and, therefore, will not supply substantial heat. In fact, this category of fireplace will often use the greatest amount of gas at the lowest range of efficiencies. If you live in a warmer climate where you want the aesthetics of a fire without much heat, this may be the appliance for you. Likewise, bedrooms and smaller rooms may be a good candidate for a b-vent fireplace, but please check building codes to see if this class of fireplace is approved in your locality or for installation in the room where you'd like to use it. Local/national codes in some areas prohibit the use of b-vent rated appliances, especially in colder climates. Be aware that very "air tight" houses can cause performance problems with b-vent rated appliances, so please consult an experienced fireplace installer who can advise you on the proper installation and use you are considering. Direct Vent Fireplaces offer the most features with respect to gas consumption, efficiency ratings and venting options. A direct vent fireplace will always have a glass window because these fireplaces are sealed systems using a double walled venting system. Combustion air enters the appliance via one section of pipe while fumes and moisture are vented through the other pipe. Most often, a double wall "pipe within a pipe" system is used. Subject to each model's requirements for distance and offsets, direct vent fireplace venting may be terminated either horizontally or vertically. Efficiency rating will average 65% to 84%, similar to ratings on gas furnaces. Keep in mind that these appliances must "waste" some of the heat produced to create a draft of rising warm air to evacuate the fumes produced without aid of a forced air exhaust system. Think of direct vent fireplaces as a decorative furnace: the beauty of a realistic flame with high efficiency. This appliance is great for primary or supplental heating and for emergency backup heating as most work without aid of electricity. Because this is a sealed system that uses outside air for combustion, direct vent fireplaces are usually the favored choice among those in the fireplace industry because of their greater efficiency and exceptionally reliable performance. Hope this info helps, I am a General Contractor. Renron...See MoreNo love from 'fireplaces' forum - gas insert, anyone?
Comments (1)I have a gas fireplace and the brick right above the fireplace still gets some black soot. But my white mantel (which is closer to the fire opening) does not. But I also have a regular wood burning fireplace in another room and I don't think you will have a problem. You could try it and see if you get any smoke build up and just stop using it as soon as you see black on the bricks. I doubt it could get to your mantel since its so high above the opening. But if you keep it regularly cleaned off, it shouldn't stain your brick. You probably don't retain much heat from vented gas. It goes up the chimney like the wood fire does. But after growing up with real fires, I love my gas fireplace since I don't have to do any work to get a fire. My only beef is that the logs get lots of black soot on them and I have to clean it off at least once a year. It stains the ceramic logs and that can't be removed completely....See MoreVented Gas Fireplace Logs versus full insert?
Comments (3)Assuming your fireplace draws properly, smoke shouldn't be a problem for the existing wood fireplace - though I can appreciate your concern with the new TV, etc. If you're getting smoke in the room; the fireplace isn't functioning properly: learn about draft at http://www.highschimney.com/articles/chimney-airflow-problems/ As for gas logs, you can use vented logs all day vs a limited burn time for ventless logs. The fire will likely be adjusted to have a yellow flame (vs a blue one like your kitchen stove might) so as to look more like a wood fire. That necessarily means that you will have somewhat incomplete combustion. You'll want CO detectors around because if the exhaust isn't going up the chimney as it should be, you won't get any warning (ie no smoke to choke on). You have to put something in place to insure the fireplace damper can never close 100%- a clipboard clip on the damper plate is often used. Your fireplace has to still work for wood, so don't let anyone suggest you have a smaller liner. This is not something you install yourself; a plumber will run the gas line. I'd suggest getting your log set in a hearth store, where they'll cost more no doubt, but you'll also get knowledgeable people and access to professional installation. And you are right: you do lose heat with an open fireplace. I love the official expression for it: "negative heat gain." Here is a link that might be useful: Types of gas firepaces...See MoreSusan
last yearAustin Lee
last year
lucky998877
last yearYou said how to reduce the heat to the surface above...this is what I did. This hollow metal mantle will not let the heat rise above it. Gets very hot below, totally cool ontop... I can have candles on the mantle and they don't melt. I have a TV mounted there which is why I researched it so much. But yes, this is a very different style than your wooden one.
PROBeth H. :
last yearlast modified: last yearI read over the G4 install instructions :
Be aware of hot wall surfaces!
The wall directly above the fireplace can get very hot when the fireplace heats. Although safe, it may reach temperatures in ex- cess of 200oF (93°C) depending on choice of optional accessories. Do not touch!
- Be aware of hot shelf/hearth/floor surfaces! Any projections directly around the fireplace can get very hot when the fireplace heats. Although safe, they may reach temperatures in excess of 200oF (93°C) depend- ing on their elevation. Be careful of touching these! Do not put objects on the hearth or shelf. Temperature of projection surfaces will be reduced when barrier screens are installed.
- Some parts of the fireplace are extremely hot, particu- larly the glass window. Use the barrier screen provid- ed or a gate to reduce the risk of severe burns. The glass windows can exceed 500°F at full capacity.
I suggest you read page 4 for the safety concerns. Nothing should be within 3 feet of this unit!
You have the glass barrier on there, yes? (hard to see in the photo)
The glass front assembly must be in place and sealed before the unit can be placed into safe operation.
Venting ok?
This gas fireplace and vent assembly must be vented directly to the outside and must never be attached to a chimney serving a separate solid fuel burning ap- pliance. Each gas appliance must use a separate vent system. Common vent systems are prohibited.
Finishing Materials
Combustible Materials: Materials made of or surfaced with wood, compressed paper, plant fibers, plastics, or other material that can ignite and burn, whether flame proofed or not, or plastered or unplastered.
What kind of plaster did you use? you would need to check w/that company to see if there is a heat restriction. if there is, you may have to remove and instead float the surface w/a cement or stucco material that is more resistant to heat.
Materials that are reported as passing ASTM E 136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 °C.WARNING
Some materials or items, although safe, may discolor, shrink, warp, crack, peel, and so on because of the heat produced by the fireplace. Avoid placing candles, paintings, photos, and other items sensitive to heat around the fireplace
Installation PlanningBefore Installation
- YOU NEED TO KNOW FROM THE HOMEOWNER:
Whether any facing material will be used over
the existing fireplace. - What trim, front, and optional accessories (if
any) will be installed with this unit.
This is not a DIY thing, so I'm glad you had a pro. If you want to read over the specs,https://www.valorfireplaces.com/media/G4/english/785YN-P-Installation.pdf
Just insure that everything was done correctly.
Other than that, I think the plaster you've applied doesn't meant the heat specs. Best to remove and do something else. Over CEMENT BOARD with nothing combustible behind it.You can investigate this further, but I think they have a heat resistant plaster/stucco for fireplaces and such.
https://www.plasterersnews.com/heat-resistant-plaster/
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