HIGH HUMIDITY 60 % +. Within the last month, I moved into a new house. It has dry walls and not plaster walls. The furnace and hot water tank were installed a week or so before we moved in to the house. Last week we determined that there is a humidity issue when the windows were sweating. We are trying to determine the source of the humidity. The contractor feels it may be the high efficiency furnace. I have a Lennox g61mp. The combustion air is pulled from within the un finished basement. Should the air be pulled from the outside? The gases are vented via PVC pipe which slopes back to the furnace.
Could the furnace be causing the humidity problem? If yes, what could be causing the humidity problem? The installer said it is not the furnace.
Maintaining the proper humidity levels in the home is important not only for health (as indicated on High Performance HVAC Humidifiers Page) but also for the wood products in the home including doors and windows. The quick answer to your question about the furnace causing the humidity problems is no. Gas furnaces and other heating appliances tend to dehumidify the air and do not create any more humidification. I wonder where your supply vents are located and are they directed to blow hot air towards the windows? Condensation is created when the temperature of air is colder than the dew point. A prime place for this to occur is windows and doors. This is part of the reason why many supply vents for forced air systems, and radiators for hot water systems, are placed near windows and doors. It keeps the windows warmer and above the dew point and also makes the air warm from your heat loss near these locations.
Lennox G61MP Gas Furnace
The furnace you describe, the Lennox G61MP, is a condensing furnace and having the combustion air intake in the basement actually contributes to removing humidity from the basement. It sucks the air from the basement for use in the combustion process and the humidity in this air is condensed during the combustion process in the heat exchanger. This condensation is gotten rid of down a condensation drain near the furnace or blown out the exhaust where the combustion gases are expelled. If your supply vents are located near the doors and windows and you still have this problem then it may be time for new doors and windows as you have too much heat loss at these places and all the humidity is being condensed around the windows in your home.
Home Humidity Problems Maintaining Proper Home Humidity
17) I have a Heil gas/electric package unit in my home. I, particularly, want to know, if I can close off a section to save on heating. Heating dealers have not been helpful as they hedge on whether and how this can be done with the system still running at it’s most efficient. I have closed doors to seal off area. Then closed floor registers. Should I also close air return in that area? I just read this should not be done at all as it decreases units efficiency? Will you please advise. I am thinking of closing off part of the house to save energy on HVAC. Thank you.
Hello and Thank you for emailing High Performance HVAC, Dorothy, Your registers should not be closed off as it is bad for the unit. The unit was installed based on the size of your home and the needed airflow for the house. This is designed airflow and requires all registers to be open to get the designed airflow through the unit and all the ducts. Closing off registers restricts airflow and is the same as a dirty filter which restricts airflow and causes problems with the unit. I have seen this before and I cover this on the HVAC filter page. In a gas pack it will cause excessive heat build up inside the unit and cause the unit to trip on high limit safety if you close off too many registers as the required airflow is not moving across the heat exchange so the heat continues to build up in the heat exchanger and eventually trips this high limit safety. Leave all your registers open and make sure you have a clean filter to maximize the unit. The best way to get the most efficiency out of the unit is to get a programmable thermostat and run the unit only as necessary. For more information on this see the thermostat pages concerning programmable thermostats and there use. Additionally, making sure you have good windows and doors to minimize heat loss will also help. Adding insulation to your attic space and other areas will also help reduce the amount the unit runs will result in savings and additionally having a humidifier installed will also help you remain comfortable in the winter time. For more information on why a humidifier will help you remain more comfortable in the winter see the humidifiers page.
Thanks for emailing High Performance HVAC. Hope this helps you.
Richard High Performance HVAC
Richard Many thanks for your very prompt response! What you say ties in with what I read regarding stress on the unit. However, this Victorian “cottage” is 3,000 sq. ft. w/ 12 ft. ceilings is now too big for only my husband and I. Is there not a way we can isolate the unused space and save on heating without stressing the unit? We have done all that you suggested. Storm windows, doors, etc., except for the attic insulation. The company that installed the unit is no longer in business and the man that I got to service it after that died. last fall. I’m in a very small town and the nearest Heil dealers seem to be 40 or more miles away. I did print a list of those I found. Haven’t called any yet as I ran across your webpage. My final question is, given the size of the unit, could I convert to 2 zones somehow? And, only heat the occupied part in winter? Thanks for you patience and help.
No unless you installed a whole new system (two new systems for zoning) or de-rating your current unit and buy another smaller unit. Also it doesn’t have to be a Heil dealer to work on the unit. Many gas packs are very similar in design and functionality. Any qualified HVAC tech should completely understand your unit and how to repair it. Not many would know how to de-rate it though. This would likely need Heil involved to give you the engineering data for derating and exactly how to derate the equipment. We are talking about a 2 ton system (I think) so you can’t derate too much. Generally the tonnage is the size of the air conditioning and doesn’t refer to the heating because the system is designed for airflow for air conditioning. You don’t want to derate the air conditioning but you can derate the gas heater side of the equipment. If the unit is older than 5 years I don’t recommend this. Richard
Closing Off Part of the House To Save Energy on HVAC
With the ever increasing cost of energy we must ask ourselves how can we save energy? This question can be answered easily by someone who understands energy saving methods and I will show you different ways to save energy.
Why do we want to save energy? To many this question is easy to answer and while some be thinking the answer is axiomatic you may be surprised at how some people answer that question. To me the core reason for saving energy is two things: 1) To save money and 2) It is incredibly irresponsible to waste good energy. It is kind of like cooking a Porterhouse T-bone and only eating half and throwing the rest of the delicious steak away. What an incredible waste! I am sure others may answer the question in a different way including the greenies who would say many things that include environmental concerns however I wish to remain A-political in my technical writing (including my responses to comments) so I will refrain from telling others what I think of the Greenies and their impossible disingenuous agenda. So read on for energy saving options to help yourself. Continue reading “How to Save Energy: Methods of Saving Energy Google PowerMeter” »