Options Needed to Replace Ancient Apartment Boilers

[Mechblue]

I have two 8 unit buildings in Michigan. They are each heated by a large central boiler circa 1950. None of the units have A/C or individual thermostats. This results in HUGE operational costs and very low occupant satisfaction, as they can't control the temperature at all. The apartments range from 650 sf to 800 sf, and are on crawl spaces with a relatively shallow pitch roof above. The apartments are in the downtown of a fairly affluent area. I need to do something about the heating/cooling situation in order to bring the rents in line with the market.

I've spent a lot of time reading about the pros and cons of different heating systems. I'd like to investigate putting a series of high velocity heat and AC units in the attic space (1 per apartment). I'm considering this because the ductwork for a LV system is not feasible given the structure I'm dealing with (I think). Both buildings are single story, and the gas and electricity are already individually metered and available at each apartment.

Okay, so now you have some background, here are the questions: Are HV systems generally suitable for an attic space for both heating and cooling in my area? All of the houses I've ever owned/seen have the HVAC in the unit or in the basement. Has anyone ever heard of such a retrofit on an apartment building? Are the issues with drainage etc. that I've read about with HV systems avoidable via a knowledgeable installer or am I looking for a problem? What type of venting would be required for such an attic installation (assuming natural gas for heat)?

Thanks for any feedback you can provide.

[BaldLoonie]

HV air handlers don't have provision for gas heat. They can have a water coil for hot water off a boiler. Or electric heat with straight cool or heat pump though I hate seeing a heat pump on HV air handlers due to the low airflow. They are great to be in an attic.

[Mechblue]

HV air handlers don't have provision for gas heat. They can have a water coil for hot water off a boiler. Or electric heat with straight cool or heat pump though I hate seeing a heat pump on HV air handlers due to the low airflow. They are great to be in an attic.

Would a heat pump/electric heat provide sufficient heating in order to keep the units comfortable? Most of the heat here in SE Michigan is natural gas based. How would the operating costs for an electric unit compare to a LV natural gas furnace (I know there are not enough details to really answer that but guesstimate is fine by me.) Could I install a gas fired boiler right next to the HV air handler? Sorry if that's a stupid question.

[R123]

You could also put in some ductless mini splits or PTAC's

[jtrammel]

Would a heat pump/electric heat provide sufficient heating in order to keep the units comfortable? Most of the heat here in SE Michigan is natural gas based. How would the operating costs for an electric unit compare to a LV natural gas furnace (I know there are not enough details to really answer that but guesstimate is fine by me.) Could I install a gas fired boiler right next to the HV air handler? Sorry if that's a stupid question.

I'm sure there is a way to get conventional (LV) duct in, how high is the crawlspace? The operating costs of electric heat would be really high in Michigan, enough to not keep tenants very long. Have some contractors out to take a look and give you some different options.

[HVACCory617]

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[jpsmith1cm]

HVACCory617

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[MicahWes]

I agree with R123. Those small apartments sound like a great application for mini-splits. You might even be able to put a ducted mini-split in so that the bedroom can have a supply.

[Poodle Head Mikey]

What I would push for would be a HV A/C system for each unit with a hydronic heating coil in the return duct. I like to lay the water coils in right above the large ceiling-mount air-return filter-grille.

And install a tankless water heater for each unit's domestic hot water.

And use a small bronze pump and a stainless steel plate frame HX to make the heating water.

PHM
------

I have two 8 unit buildings in Michigan. They are each heated by a large central boiler circa 1950. None of the units have A/C or individual thermostats. This results in HUGE operational costs and very low occupant satisfaction, as they can't control the temperature at all. The apartments range from 650 sf to 800 sf, and are on crawl spaces with a relatively shallow pitch roof above. The apartments are in the downtown of a fairly affluent area. I need to do something about the heating/cooling situation in order to bring the rents in line with the market.

I've spent a lot of time reading about the pros and cons of different heating systems. I'd like to investigate putting a series of high velocity heat and AC units in the attic space (1 per apartment). I'm considering this because the ductwork for a LV system is not feasible given the structure I'm dealing with (I think). Both buildings are single story, and the gas and electricity are already individually metered and available at each apartment.

Okay, so now you have some background, here are the questions: Are HV systems generally suitable for an attic space for both heating and cooling in my area? All of the houses I've ever owned/seen have the HVAC in the unit or in the basement. Has anyone ever heard of such a retrofit on an apartment building? Are the issues with drainage etc. that I've read about with HV systems avoidable via a knowledgeable installer or am I looking for a problem? What type of venting would be required for such an attic installation (assuming natural gas for heat)?

Thanks for any feedback you can provide.

[Poodle Head Mikey]

What I would push for would be a HV A/C system for each unit with a hydronic heating coil in the return duct. I like to lay the water coils in right above the large ceiling-mount air-return filter-grille.

And install a tankless water heater for each unit's domestic hot water.

And use a small bronze pump and a stainless steel plate frame HX to make the heating water.

PHM
------

I have two 8 unit buildings in Michigan. They are each heated by a large central boiler circa 1950. None of the units have A/C or individual thermostats. This results in HUGE operational costs and very low occupant satisfaction, as they can't control the temperature at all. The apartments range from 650 sf to 800 sf, and are on crawl spaces with a relatively shallow pitch roof above. The apartments are in the downtown of a fairly affluent area. I need to do something about the heating/cooling situation in order to bring the rents in line with the market.

I've spent a lot of time reading about the pros and cons of different heating systems. I'd like to investigate putting a series of high velocity heat and AC units in the attic space (1 per apartment). I'm considering this because the ductwork for a LV system is not feasible given the structure I'm dealing with (I think). Both buildings are single story, and the gas and electricity are already individually metered and available at each apartment.

Okay, so now you have some background, here are the questions: Are HV systems generally suitable for an attic space for both heating and cooling in my area? All of the houses I've ever owned/seen have the HVAC in the unit or in the basement. Has anyone ever heard of such a retrofit on an apartment building? Are the issues with drainage etc. that I've read about with HV systems avoidable via a knowledgeable installer or am I looking for a problem? What type of venting would be required for such an attic installation (assuming natural gas for heat)?

Thanks for any feedback you can provide.

[ammoniadog]

Are you trying to push the utility costs onto your tenants, or are you OK with continuing to pay the heating bill?

You didn't mention what type of boiler system you have, but there are usually cost effective ways to retrofit thermostat controls on the heating units. If you have radiators, they make valves that you can put on them that have a knob that can be set to maintain temperature in the space. They don't need any electricity to make them work. That might be an option worth checking into.