Chicago Multi-family HVAC Retrofit

[Vijay T.]

Hello,

My apologies if this topic is covered elsewhere. If so, feel free to point me to it.

We are about to acquire a 10+ unit multi-family residential building in Chicago built c. 1970, and are exploring options for updating the HVAC.

There is currently a hot water boiler (three actually, and the original ones) for baseboard heat common to the whole building. Also, there are common domestic hot water tanks (gas paid by the owner), and a single gas meter so all tenants' cooking gas is paid by the owner as well.

We are exploring options for reducing the high gas-utility expense. Ideally, all of the tenants would pay for their own gas use (they are currently metered individually for electricity). The cost of doing so is the main question we are exploring.

The main unknown: the logistics/cost of running individual gas lines to each unit and giving each a separate gas meter.

Here are some of the options we are considering:
1) Keep the system basically as is, but update it for greater energy efficiency.
- Install two new high efficiency condensing boilers, and update windows and insulation for better heat loss performance.
PROS - a) minimally invasive; b) can provide 15-30% reduction in heating costs (we are told).
CONS - a)total gas expense is still paid by the landlord; b) individual units won't have individual control (except for a thermostat controlled shutoff valve for heat/water in each unit); c) AC would be available on with in wall/window units.

2) Try to individually meter each units' gas and provide each with a traditional forced air heating/cooling system.
PROS: a)gas expense could be completely removed for landlord (huge)- even tankless hot water could be installed in each unit; b) each unit would have their own climate control.
CONS: a) constructions costs of running new gas lines and soffiting sheet metal duct work. b) highly invasive with collateral construction costs; c) future costs of maintenance on multiple systems vs a single building-wide system.

3) An electric based heating system
- This is tricky in my mind because of the high cost of electric heat. We live in Chicago with harsh winters and expensive electric supply costs. I can't imagine shouldering that expense as a tenant, although I've been told that there are a number of nice buildings that utilize primarily electric heat.
- Also, we would have to run 220 lines to each unit.

4) Mini-split system.
PROS: a) minimally invasive; b) individual unit and in-unit-zone control; c) high efficiency
CONS: a) given Chicago's extreme cold snaps in winter, they cannot be (according to code) used as a "primary" heat source.
- One possible solution would be to keep the existing boiler/baseboard system for backup and/or use in extreme cold (possibly triggered by an outside temperature sensor). Then, of course, we haven't eliminated the heating gas expense, only reduced it. To what extent, is the question.
- Another solution would be to supply supplemental heat via electric baseboard heaters.


There a few moving parts to figure out here.

I'm sure that many people have experience with this very issue, and I'd love to hear about it!~

Thanks!

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[Laura Bottorff]

Thanks for the update, @Vijay T.! It's really helpful to know how other people decided. 

@John Warren: Thank you for chiming in! Would you have a moment to give your opinion on my specific issue (details below)?

I'm owner-occupying my 4-unit, and it is otherwise currently unrented while I work on other needed repairs. I recently had one of my steam pipes leak and then break (I found it on Thanksgiving...a wonderful holiday surprise!) which steamed my entire basement, buckled the hardwood flooring in Unit 1 above, and sent steam through the back wall (all my walls are hollow/uninsulated here in a 100 year old brick building) all the way through up Unit 1, 2, and 3. So...I have a bunch of flooring out right now in Unit 1 and at least some plaster and drywall rehab to complete in all of the units through that insurance claim now. I was going to wait to do a forced air/heat install until the next time I needed to replace one of the unit's floors (estimated at 4-5yrs from now)...but that decision timeline has now been accelerated because of the water damage disaster floor removal. The steam system has been giving me problems in general since I bought the place, and I am concerned about having future leaks/damaging events like the one I'm going through now. 

The 3 main units are large (3-bedroom, all Queen+ sized) with separate dining and living rooms - so I feel that Electric heating will be too pricey - especially considering that the vinyl windows are not very well sealed and I do not currently have the budget to replace. Electric does sound like a good choice for the 1-bedroom Garden/Basement unit. Cooking gas is already separated for Units 2 & 3 and I had intended to work on getting a separate meter for Unit 1 (probably leave G on the building meter). Electric is separate for all units and I recently increased my service to 400 AMP while completing a necessary electrical box repair.

The building is definitely not in an A-class neighborhood, but it's been gentrifying and was recently reclassified as West Town (was considered part of Humboldt Park when I purchased). It's probably somewhere around B. Previous tenants have had to purchase 6-8 window air conditioning units for summer...which seems like an unreasonable ask to me, but I'm not originally from the Midwest so I'm not sure what the perception on that type of purchase typically is here among natives.