All Forum Posts by: Tom W.

Mayer M. It can be VERY difficult to sell a house with an underground oil tank. Most lenders will not provide financing for such a property. In addition, any real estate attorney worth his price will advise the buyers not to purchase the property until the tank is removed and state certification has been received proving that there is no underground contamination.

@Nicholas D.

Based on the square footage per unit that you provided, I would estimate that you would need less than 40,000 BTU of heating output for each. This is just an estimate and should be verified by heat loss calculations but it should suffice for budget purposes. You can also do a close estimate by adding up the linear footage of radiation in the space and calculating total required BTU's. Standard hot water baseboard produces approximately 500 BTU's per foot.

Based on the above numbers, the smallest Navien boiler would do well for you. It has a heating input range of 12,000 to 60,000 BTU's with a maximum output of 56,000 BTU's. The input is regulated by the boilers internal controls based on water temperature in and out so they are very efficient. They will only produce as much heat as is required based on outdoor temperatures. The same boiler will increase it's input as high as 120,000 BTU's for domestic hot water so there is always plenty of hot water for showers and sinks.

Another nice feature for you as the owner is the ability to monitor and and make adjustments to these boilers via a smart phone app. 

@Nicholas D.

I have installed several different manufacturer's brands of combi boilers. I recommend and have installed the Navien NCB series unit in my own personal projects. TriAngle Tube and Weil-McLain are two other manufacturers that provide reliable products

@Nicholas D.

Ductless split heat pumps are an option but they can be problematic in the northeast. Heat pumps work on the premise that no matter how cold it is outside, it can always get colder. In other words, there is some heat that can be used. The outdoor section of a heat pump extracts that heat from outside and transfers it inside. With older heat pumps, they would only work down until it got down into the 40's outside before they lost most of their ability to extract that heat and would then switch over to electric resistance heating. The newer ductless units are much more efficient and most are rated down to about 5 degrees outdoor temperature while still producing about 60 percent of their maximum rated capacity. That's the good news.

The bad news is that the colder it gets, the more these units need to defrost themselves. Ice builds up on them as a part of normal operation. When they go into defrost mode they stop producing heat. This might not be a big deal when outdoor temperatures are in the upper 30's but when it drops down to the teens or single digits for extended periods of time it can be problematic. The temperature indoors may drop faster than the unit is able to recover it because of multiple or extended defrost cycles per hour. In other words they will be producing less heat at the times when it is needed the most. When you add in additional factors like deep snow drifts around the outdoor unit, the problems begin to compound.

A better solution for you may be to go with gas fired "combi" boilers, one for each apartment as you renovate. A combi-boiler is a small, wall mounted, high efficiency unit that will produce hot water for both heating and domestic hot water. For the small square footage that you have indicated you're probably going to be looking for smaller units that are relatively less expensive. Air conditioning could then be provided by either window units or, depending on your budget, ductless split cooling only units.

@William Horsey 

Mechanical code allows for the use of drywall cavities to move air as long as certain parameters are followed.

1) They cannot be used for supply air

2) They cannot be part of a fire resistance rated assembly

3) They cannot convey air from more than one floor level

4) They have to be isolated from adjacent concealed spaces by fireblocking

5) They cannot be used in exterior walls

In addition, there must be a direct, sealed connection to the furnace. No return can be drawn from the room in which the furnace is located.

@Dan Fornelli

The link you attached is for a 6" chimney liner. You mentioned that this is for a 6 unit apartment building which I would assume has a larger heating unit. The liner kit you are looking at may be undersized for the application. Installing an undersized liner could be just as hazardous as having no liner at all. You should contact a qualified HVAC contractor in your area to have the job done properly. Installation of a liner is not really a high tech job and anyone can do it but chimney sizing is critical and must be matched to the BTU input of all the appliances.

@Dar Fornelli This is a life safety issue and a must fix. Carbon monoxide seeping through the bricks and mortar is colorless, odorless and deadly. Do the right thing. Take the credit and use it to fix the problem ASAP.

@Ryan Kurth

I'm an HVAC contractor and I have a few, used, warm air furnaces that I keep around for emergency and/or construction use. I'm a little too far to be of any help to you but I would suggest contacting your HVAC contractor and see if there is anything he can do to help you out.

@Maybelle Francisco

If your buyer is financing, it is highly unlikely that the lender will approve the loan knowing there is an underground storage tank on the property. Even if it was "properly" abandoned years ago, the possibility remains of soil contamination below the tank. Lenders do not want to take the chance on potential liability.

Pat Jackson As an HVAC contractor myself, I wouldn’t touch it. Too much liability. I would require the owner have the abatement done prior to my work.